The total process by which organisms produce offspring. (Stedman, 25th ed)
Reproduction without fusion of two types of cells, mostly found in ALGAE; FUNGI; and PLANTS. Asexual reproduction occurs in several ways, such as budding, fission, or splitting from "parent" cells. Only few groups of ANIMALS reproduce asexually or unisexually (PARTHENOGENESIS).
The expected number of new cases of an infection caused by an infected individual, in a population consisting of susceptible contacts only.
The capacity to conceive or to induce conception. It may refer to either the male or female.
Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
Sexual activities of animals.
The totality of characteristics of reproductive structure, functions, PHENOTYPE, and GENOTYPE, differentiating the MALE from the FEMALE organism.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The normal length of time of an organism's life.
Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.
The process of laying or shedding fully developed eggs (OVA) from the female body. The term is usually used for certain INSECTS or FISHES with an organ called ovipositor where eggs are stored or deposited before expulsion from the body.
A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.
The number of offspring produced at one birth by a viviparous animal.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
The number of offspring produced at one birth by an oviparous or ovoviviparous animal.
Conception after the death of the male or female biological parent through techniques such as the use of gametes that have been stored during his or her lifetime or that were collected immediately after his or her death.
A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
Achievement of full sexual capacity in animals and in humans.
The capability of producing eggs (OVA) from which young are hatched outside the body. While mostly referring to nonmammalian species, this does include MAMMALS of the order MONOTREMATA.
Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.
The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.
Asexual reproduction resulting in the formation of viable seeds from FLOWERS without fertlization (i.e. use of POLLEN). Progeny plants produced from apomictic seeds are perfect clones of the parent.
The number of males per 100 females.
The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
Intercellular signaling peptides that were originally characterized by their ability to suppress NEOPLASM METASTASIS. Kisspeptins have since been found to play an important role in the neuroendocrine regulation of REPRODUCTION.
Diminished or absent ability of a female to achieve conception.
The reproductive organs of plants.
The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.
The active production and accumulation of VITELLINS (egg yolk proteins) in the non-mammalian OOCYTES from circulating precursors, VITELLOGENINS. Vitellogenesis usually begins after the first MEIOSIS and is regulated by estrogenic hormones.
The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.
A class of minute animals of the phylum Aschelminthes.
An assisted fertilization technique consisting of the microinjection of a single viable sperm into an extracted ovum. It is used principally to overcome low sperm count, low sperm motility, inability of sperm to penetrate the egg, or other conditions related to male infertility (INFERTILITY, MALE).
Women who allow themselves to be impregnated with the understanding that the offspring are to be given over to the parents who have commissioned the surrogate.
The gamete-producing glands, OVARY or TESTIS.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Fungal genes that mostly encode TRANSCRIPTION FACTORS. In some FUNGI they also encode PHEROMONES and PHEROMONE RECEPTORS. The transcription factors control expression of specific proteins that give a cell its mating identity. Opposite mating type identities are required for mating.
The ratio of the number of conceptions (CONCEPTION) including LIVE BIRTH; STILLBIRTH; and fetal losses, to the mean number of females of reproductive age in a population during a set time period.
Social structure of a group as it relates to the relative social rank of dominance status of its members. (APA, Thesaurus of Psychological Index Terms, 8th ed.)
The fertilizing element of plants that contains the male GAMETOPHYTES.
The element in plants that contains the female GAMETOPHYTES.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
Human behavior or decision related to REPRODUCTION.
The transfer of mammalian embryos from an in vivo or in vitro environment to a suitable host to improve pregnancy or gestational outcome in human or animal. In human fertility treatment programs, preimplantation embryos ranging from the 4-cell stage to the blastocyst stage are transferred to the uterine cavity between 3-5 days after FERTILIZATION IN VITRO.
The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
Insects of the family Formicidae, very common and widespread, probably the most successful of all the insect groups. All ants are social insects, and most colonies contain three castes, queens, males, and workers. Their habits are often very elaborate and a great many studies have been made of ant behavior. Ants produce a number of secretions that function in offense, defense, and communication. (From Borror, et al., An Introduction to the Study of Insects, 4th ed, p676)
A genus of bacteria comprised of a heterogenous group of gram-negative small rods and coccoid forms associated with arthropods. (From Bergey's Manual of Systematic Bacteriology, vol 1, 1984)
The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.
Animal behavior associated with the nest; includes construction, effects of size and material; behavior of the adult during the nesting period and the effect of the nest on the behavior of the young.
Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.
Any of numerous winged hymenopterous insects of social as well as solitary habits and having formidable stings.
A family (Aphididae) of small insects, in the suborder Sternorrhyncha, that suck the juices of plants. Important genera include Schizaphis and Myzus. The latter is known to carry more than 100 virus diseases between plants.
The relationships of groups of organisms as reflected by their genetic makeup.
Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.
Genotypic differences observed among individuals in a population.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
A plant genus of the family CAMPANULACEAE used medicinally and is a source of LOBELINE.
Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
The physical measurements of a body.
The external elements and conditions which surround, influence, and affect the life and development of an organism or population.
A growth from a pollen grain down into the flower style which allows two sperm to pass, one to the ovum within the ovule, and the other to the central cell of the ovule to produce endosperm of SEEDS.
The condition of carrying two or more FETUSES simultaneously.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.
Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.
Phospholipoglycoproteins produced in the fat body of egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. Vitellogenins are secreted into the HEMOLYMPH, and taken into the OOCYTES by receptor-mediated ENDOCYTOSIS to form the major yolk proteins, VITELLINS. Vitellogenin production is under the regulation of steroid hormones, such as ESTRADIOL and JUVENILE HORMONES in insects.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The discharge of an OVUM from a rupturing follicle in the OVARY.
Techniques for the artifical induction of ovulation, the rupture of the follicle and release of the ovum.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
The period of cyclic physiological and behavior changes in non-primate female mammals that exhibit ESTRUS. The estrous cycle generally consists of 4 or 5 distinct periods corresponding to the endocrine status (PROESTRUS; ESTRUS; METESTRUS; DIESTRUS; and ANESTRUS).
The transfer of POLLEN grains (male gametes) to the plant ovule (female gamete).
A large family of fruit flies in the order DIPTERA, comprising over 4,500 species in about 100 genera. They have patterned wings and brightly colored bodies and are found predominantly in the tropical latitudes.
Number of individuals in a population relative to space.
Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Procedure of producing an imprint or negative likeness of the teeth and/or edentulous areas. Impressions are made in plastic material which becomes hardened or set while in contact with the tissue. They are later filled with plaster of Paris or artificial stone to produce a facsimile of the oral structures present. Impressions may be made of a full complement of teeth, of areas where some teeth have been removed, or in a mouth from which all teeth have been extracted. (Illustrated Dictionary of Dentistry, 1982)
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.
Elements of limited time intervals, contributing to particular results or situations.
Reproductive bodies produced by fungi.
The family of agile, keen-sighted mongooses of Asia and Africa that feed on RODENTS and SNAKES.
The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.
Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.
Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.
Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.
Chemical substances, excreted by an organism into the environment, that elicit behavioral or physiological responses from other organisms of the same species. Perception of these chemical signals may be olfactory or by contact.
The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
Any behavior caused by or affecting another individual, usually of the same species.
The deposit of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.
The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.
The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Exogenous agents, synthetic and naturally occurring, which are capable of disrupting the functions of the ENDOCRINE SYSTEM including the maintenance of HOMEOSTASIS and the regulation of developmental processes. Endocrine disruptors are compounds that can mimic HORMONES, or enhance or block the binding of hormones to their receptors, or otherwise lead to activating or inhibiting the endocrine signaling pathways and hormone metabolism.
The physiological processes, properties, and states characteristic of plants.
The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.
The male reproductive organs. They are divided into the external organs (PENIS; SCROTUM;and URETHRA) and the internal organs (TESTIS; EPIDIDYMIS; VAS DEFERENS; SEMINAL VESICLES; EJACULATORY DUCTS; PROSTATE; and BULBOURETHRAL GLANDS).
Substances used to create an impression, or negative reproduction, of the teeth and dental arches. These materials include dental plasters and cements, metallic oxide pastes, silicone base materials, or elastomeric materials.
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
Social rank-order established by certain behavioral patterns.
The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.
Periodic casting off FEATHERS; HAIR; or cuticle. Molting is a process of sloughing or desquamation, especially the shedding of an outer covering and the development of a new one. This phenomenon permits growth in ARTHROPODS, skin renewal in AMPHIBIANS and REPTILES, and the shedding of winter coats in BIRDS and MAMMALS.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
Compounds, either natural or synthetic, which block development of the growing insect.
Physiological processes, factors, properties and characteristics pertaining to REPRODUCTION.
A neuropeptide that is highly homologous to GALANIN. It is produced by proteolytic processing of a larger protein that is unrelated to prepro-galanin and preferentially binds to GALANIN-2 RECEPTOR.
Morphological and physiological development of EMBRYOS.
The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).
The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. In addition to reproductive organ secretions, it contains SPERMATOZOA and their nutrient plasma.
The process of germ cell development in plants, from the primordial PLANT GERM CELLS to the mature haploid PLANT GAMETES.
An order of BIRDS comprising the waterfowl, particularly DUCKS; GEESE; swans; and screamers.
An order of BIRDS including over 300 species that primarily inhabit coastal waters, beaches, and marshes. They are comprised of shorebirds, gulls, and terns.
Common name for perch-like fish of the family Cichlidae, belonging to the suborder Labroidei, order PERCIFORMES.
The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus (the body) which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
The selection or choice of sexual partner in animals. Often this reproductive preference is based on traits in the potential mate, such as coloration, size, or behavioral boldness. If the chosen ones are genetically different from the rejected ones, then NATURAL SELECTION is occurring.
Non-native organisms brought into a region, habitat, or ECOSYSTEM by human activity.
Transfer of preovulatory oocytes from donor to a suitable host. Oocytes are collected, fertilized in vitro, and transferred to a host that can be human or animal.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
A technique in assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED) consisting of hormonal stimulation of the ovaries, follicular aspiration of preovulatory oocytes, in-vitro fertilization, and intrafallopian transfer of zygotes at the pronuclear stage (before cleavage).
A family of freshwater fish comprising the minnows or CARPS.
Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.
Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
An extensive order of highly specialized insects including bees, wasps, and ants.
Relationship between individuals when one individual threatens or becomes aggressive and the other individual remains passive or attempts to escape.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.
Animals and plants which have, as their normal mode of reproduction, both male and female sex organs in the same individual.
Expulsion of the product of FERTILIZATION before completing the term of GESTATION and without deliberate interference.
Artificial introduction of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.
Increase, over a specific period of time, in the number of individuals living in a country or region.
The female reproductive organs. The external organs include the VULVA; BARTHOLIN'S GLANDS; and CLITORIS. The internal organs include the VAGINA; UTERUS; OVARY; and FALLOPIAN TUBES.
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.
The science of breeding, feeding and care of domestic animals; includes housing and nutrition.
The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)
The mating of plants or non-human animals which are closely related genetically.
PASSERIFORMES of the suborder, Oscines, in which the flexor tendons of the toes are separate, and the lower syrinx has 4 to 9 pairs of tensor muscles inserted at both ends of the tracheal half rings. They include many commonly recognized birds such as CROWS; FINCHES; robins; SPARROWS; and SWALLOWS.
A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).
Pheromones that elicit sexual attraction or mating behavior usually in members of the opposite sex in the same species.
The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Insect members of the superfamily Apoidea, found almost everywhere, particularly on flowers. About 3500 species occur in North America. They differ from most WASPS in that their young are fed honey and pollen rather than animal food.
A count of SPERM in the ejaculum, expressed as number per milliliter.
A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
Animals considered to be wild or feral or not adapted for domestic use. It does not include wild animals in zoos for which ANIMALS, ZOO is available.
An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.
A genus of the subfamily SIGMODONTINAE consisting of 49 species. Two of these are widely used in medical research. They are P. leucopus, or the white-footed mouse, and P. maniculatus, or the deer mouse.
Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.
The observable response an animal makes to any situation.
A genus of hamsters characterized by small size, very short tail, and short, broad feet with hairy soles.
The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.
A widely distributed order of perching BIRDS, including more than half of all bird species.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
The direct struggle between individuals for environmental necessities or for a common goal.
The family Gryllidae consists of the common house cricket, Acheta domesticus, which is used in neurological and physiological studies. Other genera include Gryllotalpa (mole cricket); Gryllus (field cricket); and Oecanthus (tree cricket).
A species of fruit fly originating in sub-Saharan Africa but widely distributed worldwide. One of the most destructive fruit pests, its larvae feed and develop on many different fruits and some vegetables.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Mechanisms that prevent different populations from exchanging genes (GENE FLOW), resulting in or maintaining GENETIC SPECIATION. It can either prevent mating to take place or ensure that any offspring produced is either inviable or sterile, thereby preventing further REPRODUCTION.
A branch of applied ethics that studies the value implications of practices and developments in life sciences, medicine, and health care.
Time period from 1701 through 1800 of the common era.
A technique that came into use in the mid-1980's for assisted conception in infertile women with normal fallopian tubes. The protocol consists of hormonal stimulation of the ovaries, followed by laparoscopic follicular aspiration of oocytes, and then the transfer of sperm and oocytes by catheterization into the fallopian tubes.
Sexual union of a male and a female in non-human species.
The number of births in a given population per year or other unit of time.
The hair of SHEEP or other animals that is used for weaving.
One of the largest orders of mostly marine CRUSTACEA, containing over 10,000 species. Like AMPHIPODA, the other large order in the superorder Peracarida, members are shrimp-like in appearance, have sessile compound eyes, and no carapace. But unlike Amphipoda, they possess abdominal pleopods (modified as gills) and their bodies are dorsoventrally flattened.
The failure of PLANTS to complete fertilization and obtain seed (SEEDS) as a result of defective POLLEN or ovules, or other aberrations. (Dict. of Plant Genet. and Mol. Biol., 1998)
Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
Cell surface receptors that respond to PHEROMONES.
The chemical reactions involved in the production and utilization of various forms of energy in cells.
Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.
Polyploidy with three sets of chromosomes. Triploidy in humans are 69XXX, 69XXY, and 69XYY. It is associated with HOLOPROSENCEPHALY; ABNORMALITIES, MULTIPLE; PARTIAL HYDATIDIFORM MOLE; and MISCARRAGES.
Determination of the nature of a pathological condition or disease in the OVUM; ZYGOTE; or BLASTOCYST prior to implantation. CYTOGENETIC ANALYSIS is performed to determine the presence or absence of genetic disease.
VERTEBRATES belonging to the class amphibia such as frogs, toads, newts and salamanders that live in a semiaquatic environment.
The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
Organs and other anatomical structures of non-human vertebrate and invertebrate animals.
Nutritional physiology of animals.
The external and internal organs related to reproduction.
An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.
The measurement of an organ in volume, mass, or heaviness.
A medical-surgical specialty concerned with the morphology, physiology, biochemistry, and pathology of reproduction in man and other animals, and on the biological, medical, and veterinary problems of fertility and lactation. It includes ovulation induction, diagnosis of infertility and recurrent pregnancy loss, and assisted reproductive technologies such as embryo transfer, in vitro fertilization, and intrafallopian transfer of zygotes. (From Infertility and Reproductive Medicine Clinics of North America, Foreword 1990; Journal of Reproduction and Fertility, Notice to Contributors, Jan 1979)
The only family of the buckwheat order (Polygonales) of dicotyledonous flowering plants. It has 40 genera of herbs, shrubs, and trees.
The detection of RESTRICTION FRAGMENT LENGTH POLYMORPHISMS by selective PCR amplification of restriction fragments derived from genomic DNA followed by electrophoretic analysis of the amplified restriction fragments.
Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

Prolactin replacement fails to inhibit reactivation of gonadotropin secretion in rams treated with melatonin under long days. (1/7797)

This study tested the hypothesis that prolactin (PRL) inhibits gonadotropin secretion in rams maintained under long days and that treatment with melatonin (s.c. continuous-release implant; MEL-IMP) reactivates the reproductive axis by suppressing PRL secretion. Adult Soay rams were maintained under long days (16L:8D) and received 1) no further treatment (control, C); 2) MEL-IMP for 16 wk and injections of saline/vehicle for the first 8 wk (M); 3) MEL-IMP for 16 wk and exogenous PRL (s.c. 5 mg ovine PRL 3x daily) for the first 8 wk (M+P). The treatment with melatonin induced a rapid increase in the blood concentrations of FSH and testosterone, rapid growth of the testes, an increase in the frequency of LH pulses, and a decrease in the LH response to N-methyl-D,L-aspartic acid. The concomitant treatment with exogenous PRL had no effect on these reproductive responses but caused a significant delay in the timing of the sexual skin color and growth of the winter pelage. These results do not support the hypothesis and suggest that PRL at physiological long-day concentrations, while being totally ineffective as an inhibitor of gonadotropin secretion, acts in the peripheral tissues and skin to maintain summer characteristics.  (+info)

Glucocorticoid receptor immunoreactivity in neurons and pituitary cells implicated in reproductive functions in rainbow trout: a double immunohistochemical study. (2/7797)

In order to identify the nature of the glucocorticoid receptor (GR)-expressing neurons and pituitary cells that potentially mediate the negative effects of stress on reproductive performance, double immunohistochemical stainings were performed in the brain and pituitary of the rainbow trout (Oncorhynchus mykiss). To avoid possible cross-reactions during the double staining studies, combinations of primary antibodies raised in different species were used, and we report here the generation of an antibody raised in guinea pig against the rainbow trout glucocorticoid receptor (rtGR). The results obtained in vitellogenic females showed that GnRH-positive neurons in the caudal telencephalon/anterior preoptic region consistently exhibited rtGR immunoreactivity. Similarly, in the anterior ventral preoptic region, a group of tyrosine hydroxylase-positive neurons, known for inhibiting gonadotropin (GTH)-2 secretion during vitellogenesis, was consistently shown to strongly express GR. Finally, we show that a large majority of the GTH-1 (FSH-like) and GTH-2 (LH-like) cells of the pituitary exhibit rtGR immunoreactivity. These results indicate that cortisol may affect the neuroendocrine control of the reproductive process of the rainbow trout at multiple sites.  (+info)

Precocious estrus and reproductive ability induced by PG 600 in prepuberal gilts. (3/7797)

A total of 29 SPF Large White prepuberal gilts (mean age 152 days at treatment) were examined for estrous and ovulatory responses after PG 600 treatment. After treatment, 85.2% of the gilts showed standing estrus within 6 days. Whereas the treatment-to-estrus interval and duration were 3.7 and 1.9 days respectively. As ovulation occurred on Day 5 to 6, appropriate timing of artificial insemination would be about 4 days after treatment. Fertility of gilts revealed to be excellent, giving rise to a high percentage of normal embryos, 85.3%. Meanwhile, development and growth of fetuses were mostly normal. Other reproductive performances recorded were: mean litter size 6.8; mean birth weight 1.26 kg; weaning-to-return estrus interval 5 to 8 days. In conclusion, PG 600 was found to be useful in inducing fertile estrus in prepuberal gilts, a result which will be of interest for commercial pig farms.  (+info)

Utero-ovarian interaction in the regulation of reproductive function. (4/7797)

The physiological regulation of fertile reproductive cycle in mammals depends on interactions between hypothalamus-pituitary, ovarian and uterine stimuli. Over the past 20 years, much has been learned about the interrelation between the affluent and effluent lymph and vascular drainage in and around both ovarian and uterine tissues. An essential feature in the regulation of the fertile cycle is the functional status of the ovary, particularly the corpus luteum. During the time of implantation and the early pregnancy, an active corpus luteum is essential. As human chorionic gonadotrophin (HCG) is important in the maintenance of the corpus luteum, we investigated if it was produced by the cyclic endometrium. Immunohistochemical and in-situ hybridization reactions were performed but neither identified the presence of HCG during the proliferative phase. Positive staining and beta-human chorionic gonadotrophin (beta-HCG) mRNA were observed during the secretory phase in the glandular cells of the endometrium. The results were confirmed by Western blotting of secretory phase endometrium extracts and assessment of the functional secretory capacity of primary endometrial cultures. Polymerase chain reaction (PCR) investigations showed a positive result in the secretory phase. We postulate that, based on the very close morphological interrelation between the uterus and the ovary, the beta-HCG of the endometrium is the primary factor for the maintenance of the corpus luteum and early pregnancy.  (+info)

The effects of a t-allele (tAE5) in the mouse on the lymphoid system and reproduction. (5/7797)

Mice homozygous for tAE5, a recessive allele at the complex T-locus, are characterized by their unique short-tailed phenotype as well as by runting and low fertility. Histological and histochemical studies of the lymphoid and reproductive systems disclosed structural changes in the mutant spleen resembling those found in autoimmune conditions. Involution of the mutant thymus was greatly accelerated compared to normal. Necrotic changes occurred during spermiogenesis whereas ovarian structure was normal in mutants. The possible mechanisms of the mutant effects are discussed in the framework of other similar syndromes and the mode of action of alleles at the complex T-locus.  (+info)

Ultrastructure of meiosis-inducing (heterotypic) and non-inducing (homotypic) cell unions in conjugation of Blepharisma. (6/7797)

Cells of mating types I and II of Blepharisma japonicum interact with each other and unite in heterotypic (type I-type II) or homotypic (type I-type I, type II-type II) pairs. Heterotypic pairs undergo meiosis and other nuclear changes of conjugation, while homotypic pairs remain united for days without the nuclear changes taking place. We compared cell unions of these two kinds of pairs at the ultrastructural level. In the homotypic union, cell membranes are closely juxtaposed, separated by a distance of about 20 nm. This arrangement is interrupted in some places by vacuoles and small cytoplasmic bridges. Saccule-like structures tend to be more abundant near the united surfaces. Microtubules running at right or slightly obtuse angles with the cell surface (PACM microtubules) are characteristically present at the united region of cells. These structures are very similar to those observed in earlier stages of the heterotypic union. However, in homotypic pairs, cells unite only at the anterior half of the peristome, while in heterotypic pairs cells unite also at the posterior half of the peristome, where the cell membrane totally disappears in later stages. PACM microtubules persist for at least 18 h in homotypic unions, while they disappear within a few hours in heterotypic unions. These differences between the two kinds of cell union are discussed in relation to the initiation mechanism of meiosis and other nuclear changes of conjugation. Similarities between homotypic union and cell junctions in multicellular organisms are also discussed.  (+info)

Evaluation of life-cycle herd efficiency in cow-calf systems of beef production. (7/7797)

A deterministic beef efficiency model (BEM) was used to evaluate life-cycle herd efficiency (LCHE) in cow-calf beef production systems using four breed groups of beef cattle. The breed groups were Beef Synthetic #1 (SY1), Beef Synthetic #2 (SY2), Dairy Synthetic (DS), and purebred Hereford (HE). The LCHE was defined over the lifetime of the herd as the ratio of total output (lean meat equivalent) to total input (feed equivalent). Breed differences in LCHE were predicted with the larger/slower maturing DS being most efficient at each age of herd disposal and reproductive rate. This was mainly because, at any average age at culling, the dams of DS breed group were less mature and so had been carrying relatively lower maintenance loads for shorter periods and positively influencing LCHE. Higher LCHE was predicted with improvement in reproductive performance if there were no associated extra costs. However, this declined markedly if there was a delay in marketing of offspring. As average age at culling increased from 4 to 6 yr, efficiency declined sharply, but it began to recover beyond this age in most breed groups. We concluded that the slower maturing DS breed group may be more efficient on a herd basis in cow-calf systems and that improvements in reproductive rate not associated with extra costs improve life-cycle efficiency. Culling cows soon after their replacements are produced seems efficient.  (+info)

Gonadotropin-releasing hormone improves reproductive performance of dairy cows with slow involution of the reproductive tract. (8/7797)

Eighty multiparous Holstein cows were assigned randomly at calving to receive either 100 microg of GnRH or saline 13 or 14 d postpartum (PP). From 4 to 28 d PP the cows' reproductive organs were palpated weekly per rectum, and cows were subclassified within each group as undergoing slow (delayed) cervical and uterine involution (abnormal) or as normal cows. Last milk obtained after removing the milking machine was assayed for progesterone 3 times a week for 120 d PP. Fourteen of the 80 cows were removed from the experiment because of culling or various veterinary treatments of pathologic conditions that could confound analysis of the GnRH treatment effects. As expected, the treatment of normal cows with GnRH had no significant effects on the first estrus or the first estrous cycle PP, on services per conception, days open, or any other reproductive trait measured. However, in the abnormal group of cows receiving saline, first rebreeding after calving was delayed (81 vs. 67 d), fewer were pregnant by 105 d PP (23 vs. 64%), and number of days open was greater (121 vs. 87 d) compared with those receiving GnRH; all were significant (P<.05). Treated abnormal cows were equivalent to the control normal cows. Thus, GnRH given 13 to 14 d PP to cows characterized as undergoing slow involution of the reproductive system, but with no other clinical problems, seems to assist in promoting rapid normal reproductive function. Subsequent losses due to culling were greatly reduced.  (+info)

Rainbow trout is a significant fish farming species under temperate climates. Female reproduction traits play an important role in the economy of breeding companies with the sale of fertilized eggs. The objectives of this study are threefold: to estimate the genetic parameters of female reproduction traits, to determine the genetic architecture of these traits by the identification of quantitative trait loci (QTL), and to assess the expected efficiency of a pedigree-based selection (BLUP) or genomic selection for these traits. A pedigreed population of 1343 trout were genotyped for 57,000 SNP markers and phenotyped for seven traits at 2 years of age: spawning date, female body weight before and after spawning, the spawn weight and the egg number of the spawn, the egg average weight and average diameter. Genetic parameters were estimated in multi-trait linear animal models. Heritability estimates were moderate, varying from 0.27 to 0.44. The female body weight was not genetically correlated to any of the
The Center for Reproductive Endocrinology and Fertility, is a company that works within the Biotech/healthcare. This Spokane, WA-based business. Their profile on Lead411 presents significant contact information such as cfo contacts, phone numbers, linkedin data, and The Center for Reproductive Endocrinology and Fertility email format addresses with the domain as well as quality contact info regarding The Center for Reproductive Endocrinology and Fertilitys CEO . They have their head office in Spokane, WA. If you sign up for our free trial you will see our [email protected] addresses ... Reproductive Endocrinology and Infertility [4172281] - Management of the modern reproductive endocrinology and infertility clinic has become very complex. In addition to the medical and scientific aspects, it is crucial that the modern director be aware of of incongruent fields such as marketing, accounting, management, and regulatory issues. Reproductive Endocrinology and Infertility: Integrating Modern Clinical and
Environmental effects on reproduction, and life history General sequence of events during mammalian reproduction, and variations: Delayed fertilization, delayed implantation, and delayed development Environmental
It has been challenging to genetically improve reproduction traits with the resources of the conventional breeding because of the low heritability of these traits. In Finland genetic improvement of the reproduction traits hasnt either meet the expectations entirely. Gene markers are one possibility to make genetic improvement of the reproduction traits more effective. With an association analysis it is possible to find those gene markers which have statistically significant effect on the trait. The purpose of this study was to identify SNP markers associated with reproduction traits in the Finnish Yorkshire pig breed. Other purpose of this study was to find out if both Finnish pig breeds have certain chromosomal regions associated with same reproduction traits. In this study one goal was also to discover genes which are placed near statistically significant SNP markers. Under this study were nine female reproduction traits which are total number of piglets born in first and later parities, ...
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Reproductive Endocrinology RE Definition - Reproductive endocrinology is a sub-specialty of Obstetrics and Gynecology that focuses on treating men and...
Costs of reproduction are the trade-offs that exist between reproductive investment and survival and/or future reproduction [1,2]. In recent years, studies have focused on the ecological and physiological basis of these costs [3,4]. Such costs include increased oxidative stress (e.g. [5]) and metabolism (e.g. [6]), impaired immune function, and decreased growth, energy stores (e.g. [7]) and endurance (e.g. [8]). Reproductive effort can also have intergenerational effects: offspring quality may decrease when reproductive investment increases, owing to a trade-off between offspring number and quality [2]. Experiments have shown the existence of such a trade-off in mammals, reptiles and birds. For example, offspring from enlarged litters [9,10] or miniaturized eggs [11] have been shown to have a lower survival [10,11], be more stressed and have a lower immune performance [9]. Therefore, parental reproductive effort is linked to offspring quality. Moreover, small offspring can show a period of ...
Definition of Proximate Cause in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is Proximate Cause? Meaning of Proximate Cause as a legal term. What does Proximate Cause mean in law?
Fitness trade-offs such as costs of reproduction are an integral component of evolutionary theory, and a common trade-off is that increased reproduction decreases longevity. Our labs interest in reproductive costs stems from its potential to reveal conserved mechanisms that regulate the aging process. When we were in the planning stage of this study, our goal was to explain a recent phenotype we observed where the lifespan of fruit flies was decreased by exposure to pheromones of the opposite sex, and mating actually partially reversed this negative effect. While we were obviously interested in the molecular mechanisms of these phenotypes, we also sought to better understand why this might occur from a conceptual level. Our first thought from this perspective was that the negative effects of pheromones in the absence of mating may be due to a mismatch between expectation and reality. In this line of thought, mating partially rescued the negative effects of pheromones on longevity because the ...
Root cause - Because the driver failed to gas up the tank. Between the remote cause and the injury, there intervened the negligence of the minors parents or the detachment of the steering wheel guide of the jeep. Click for more detail. See the PAO or IBP chapter near you for free legal aid. Proximate cause means the active, efficient cause that sets in motion a train of events which brings about a result, without the intervention of any force started and working actively from a new and independent source. Proximate cause Primary tabs An actual cause that is also legally sufficient to support liability. Remote Cause - in first-party property cases, a peril that takes place before the proximate cause-for example, in sequence of events type situations where one peril is followed by-but does not cause-a second peril that was unforeseeable at the time the policy was issued. Example: Driver of Car A runs a red light, and Car B which has a proximate cause, all causes preceding the proximate cause ...
Welcome to USF IVF and Reproductive Endocrinology at the University of South Florida Morsani College of Medicine. Our mission is to lead the way in delivering the very best infertility and reproductive endocrine (REI) care available to our patients.. Through treatments including fertility medicines, intrauterine insemination, IVF, and reproductive surgery, our team of fertility experts is committed to giving our patients the very best opportunity to achieve their dream of having a family. By collaborating with egg donors, sperm banks, and gestational surrogates, we are able to offer family building choices to women whose own eggs cannot produce a baby, to women who cannot carry their own babies, to single parents, and to same sex couples. By incorporating preimplantation genetic diagnosis, PGD, into IVF, we offer couples whose children are at risk of inheriting a genetic disease the ability to test embryos for the presence of the disease of concern. PGD also affords the opportunity for sex ...
A project in Denmark whose aim is to assess the reliability of preconceptional lifestyle and biological factors as predictors of fertility has found a pronounced effect of the contraceptive pill on markers used to assess ovarian reserve, a predictor of future reproductive lifespan. Available evidence of whether the Pill has an effect on fertility has so far been reassuring - and usual advice to those stopping the Pill is that cycles will soon revert to normal, with pregnancy likely within six months or so.(1)
TY - JOUR. T1 - Expanding reproductive lifespan. T2 - A cost-effectiveness study on oocyte freezing. AU - Van Loendersloot, L. L.. AU - Moolenaar, L. M.. AU - Mol, B. W.J.. AU - Repping, S.. AU - Van Der Veen, F.. AU - Goddijn, M.. PY - 2011/11. Y1 - 2011/11. N2 - Background The average age of women bearing their first child has increased strongly. This is an important reproductive health problem as fertility declines with increasing female age. Unfortunately, IVF using fresh oocytes cannot compensate for this age-related fertility decline. Oocyte freezing could be a solution. Methods We used the Markov model to estimate the cost-effectiveness of three strategies for 35-year-old women who want to postpone pregnancy till the age of 40: Strategy 1: women undergo three cycles of ovarian hyperstimulation at age 35 for oocyte freezing, then at age 40, use these frozen oocytes for IVF; Strategy 2: women at age 40 attempt to conceive without treatment; and the reference strategy: women at age 40 ...
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Magee-Womens Hospitals Center for Fertility and Reproductive Endocrinology offers a woman-focused approach, knowledge, and expertise to provide highly personalized reproductive health care, including evaluation, diagnosis, and treatment.
Our second expectation was that the decline in the population growth rate, as observed in wild ungulates, would be caused first by a reduction in foal survival and in reproductive performance and last by the survival of adult females. Foal survival did indeed decline strongly as density increased from 5 to 23 horses km−2. Fecundity was strongly age-structured in these horses, as in wild ungulates, and the fecundity of young females declined at high density (see Duncan 1992), though not significantly in the years up to 1981. The fecundity of young mares in Przewalskis horses (Equus przewalskii) was also density dependent, with a delayed age at first reproduction (Tatin et al. 2009). By contrast with wild herbivores, fecundity in prime-aged Camargue females remained high and quasi-constant at high density. Fecundity is an important criterion for horse breeders in the Camargue (P. Duncan 1979, personal observation), and it is possible that mares of this breed have been selected based on this ...
Our fertility doctors provide a full range of services to diagnose and treat infertility. All our doctors are are all board certified in Reproductive Endocrinology and Infertility and are focused focus solely on understanding and treating infertility conditions.
University of Marylands Division of Reproductive Endocrinology offers a full range of proven successful fertility options for individuals and couples.
Therapeutic agents used in reproductive endocrinology and infertility are in almost all cases either naturally occurring hormones or agonists and antagonists
Dr. Kroener is a Reproductive Endocrinology and Infertility Specialist. She is passionate about womens health and provides comprehensive,
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Carlene W Elsner MD is a Reproductive Endocrinology who practices in Atlanta, GA. Get a full report about this doctors background by clicking here.
Andrew J Levi MD is a Reproductive Endocrinology who practices in Trumbull, CT. Get a full report about this doctors background by clicking here.
Reproductive Endocrinology for the MRCOG and Beyond by Adam Balen, 9781904752196, available at Book Depository with free delivery worldwide.
Critical body residues (CBRs) are the measured tissue toxicant concentrations yielding a median dose-response on a dry-weight or lipid-normalized basis. They facilitate management decisions for species protection using tissue analysis. Population CBR is the mean dose yielding 50% population suppression and was predicted here in Amphiascus tenuiremis for fipronil sulfide (FS) using lifetables and the Leslie matrix. Microplate bioassays (ASTM E-2317-14) produced biomass sufficient for dry mass and lipid-normalized CBR estimates of reproduction (fertility) and population growth suppression. Significant FS toxic effects were delayed naupliar development (at ≥0.10 µg L(-1)), delayed copepodite development (at 0.85 µg L(-1)), decreased reproductive success (at ≥ 0.39 µg L(-1)), and decreased offspring production (at 0.85 µg L(-1)). A reproductive median effective concentration (EC50) of 0.16 µg L(-1) (95% CI: 0.12-0.21 µg L(-1)) corresponded to an adult all-sex CBR and lipid-normalized CBR ...
In humans, early embryo development is a complex process that consists of sequential events: oocyte maturation, fertilization, embryonic growth and implantation. Disruption of these highly regulated processes results in reproductive failure and infertility. This study characterizes and describes embryonic aneuploidy, mitochondrial content level and endometrial microbial environment related to reproductive competence, in particular instances in which failure results. To examine the molecular underpinnings of mammalian gamete and early embryo chromosome segregation, we established a comprehensive chromosomal screening (CCS) method for mice poly bodies, oocytes and embryos by the application of whole genome amplification (WGA) and next generation sequencing (NGS). First, we validated this approach using single mouse embryonic fibroblasts engineered to have stable trisomy 16. We further validated this method by identifying reciprocal chromosome segregation errors in the products of meiosis I (gamete and
Class 8 Science Question- answers. Download a PDF of free latest Sample questions with solutions for Class 8, Science, CBSE- Reproduction in Animals . To link to this page, copy the following code to your site: NCERT Exemplar for Class 8 Science Chapter 9 Reproduction in Animals is a perfect tool for your CBSE Class 8 examination. ... STUDY MATERIAL FOR CBSE CLASS 8 SCIENCE; Chapter 1 - Cell Structure and Functions This exemplar solution will make you learn the concept comprehensively by giving you extra knowledge. binary fission. 30 seconds . Reproduction: Reproduction is the process by which living organisms produce more living organisms of its own kind. 1. Next, the sperm and egg join together to form a zygote. Group: Science Science Quizzes : Topic: Life Science : Share. Poll Quiz on Reproduction in Animals. Students can solve NCERT Class 8 Science Reproduction in Animals MCQs Pdf with Answers to know their preparation level. Mode of Reproduction: There are two main types of reproduction in ...
In ecological character displacement, traits involved in reproductive isolation may not evolve in arbitrary directions when changes in these traits are by-products of adaptation to an ecological niche. In reproductive character displacement, however, selection acts directly on reproductive characters to enhance the degree of reproductive isolation between sympatric populations. Thus, the direction of change in reproductive characters may be arbitrary in relation to changes in other morphological characters. We characterized both tegminal characters and characters indicative of body size in sympatric and allopatric populations of Gryllus fultoni, a species displaying character displacement in its calling song characters in areas of sympatry with G. vernalis populations, to infer the nature and direction of selection acting on reproductive and morphological characters in sympatry. Except for mirror area, the number of teeth in a file, and ovipositor length of G. fultoni, all male and female morphological
Whether contemporary human populations are still evolving as a result of natural selection has been hotly debated. For natural selection to cause evolutionary change in a trait, variation in the trait must be correlated with fitness and be genetically heritable and there must be no genetic constraints to evolution. These conditions have rarely been tested in human populations. In this study, data from a large twin cohort were used to assess whether selection will cause a change among women in a contemporary Western population for three life-history traits: age at menarche, age at first reproduction, and age at menopause. We control for temporal variation in fecundity (the baby boom phenomenon) and differences between women in educational background and religious affiliation. University-educated women have 35% lower fitness than those with less than seven years education, and Roman Catholic women have about 20% higher fitness than those of other religions. Although these differences were ...
Current environmental risk assessment (ERA) of chemicals for aquatic invertebrates relies on standardized laboratory tests in which toxicity effects on individual survival, growth and reproduction are measured. Such tests determine the threshold concentration of a chemical below which no population-level effects are expected. How well this procedure captures effects on individuals and populations, however, remains an open question. Here we used mechanistic effect models, combining individual-level reproduction and survival models with an individual-based population model (IBM), to understand the individuals responses and extrapolate them to the population level. We used a toxicant (Dispersogen A) for which adverse effects on laboratory populations were detected at the determined threshold concentration and thus challenged the conservatism of the current risk assessment method. Multiple toxicity effects on reproduction and survival were reported, in addition to effects on the F1 generation. We ...
Comprising over 1400 species worldwide, rodents are the largest taxonomic group of mammals (Nowak 1999). Rodent use of habitats is extensive and varied. Most rodent species are relatively small, secretive, prolific, adaptable, and have continuously growing incisors which require constant eroding by gnawing. Rodents are known for their high reproductive potential; however, there is much variability between species as to the age at first reproduction, size of litters, and the number of litters per year. All rodent species have ecological, scientific, social, and/or economic values. They recycle nutrients, aerate soils, distribute seeds and spores, and affect plant succession. Some provide meat and furs for people. Several species are used in large numbers in medical research. Additionally, they provide an important prey base for many species of predatory animals.
received his Doctor of Veterinary Medicine degree from the University of Ghent (Belgium) in 2004. After completing an internship in Equine Reproduction at a large Warmblood stud farm in the Netherlands, he moved to the Unites States to complete a Residency in Equine Reproduction (University of California, UC Davis) and become board certified by the American College of Theriogenologists. After being stud veterinarian in Australia he returned in 2010 to UC Davis to serve as clinical instructor in Equine Reproduction. In 2012 he enrolled in a PhD program at the Gluck Equine Research Center (University of Kentucky, USA). In 2014, Anthony was appointed as Assistant Professor in Equine Reproduction at University of Utrecht. He is responsible for the clinical activities surrounding the OPU/ICSI program and participates in the clinical gynaecology and traditional embryo transfer activities in the equine fertility unit. He has a special interest in advanced reproductive technologies. ...
The bromophenol 2,4,6-tribromophenol (TBP) is widely used as an industrial chemical, formed by degradation of tetrabromobisphenol-A, and it occurs naturally in marine organisms. Concentrations of TBP in fish have been related to intake via feed, but little is known about effects on fish health after oral exposure. In this study, we exposed adult male and female zebrafish (Danio rerio) to TBP via feed in nominal concentrations of 33, 330, and 3300 μg/g feed (or control feed) for 6 weeks to assess the effects of TBP on reproductive output, gonad morphology, circulatory vitellogenin levels, and early embryo development. The aim was also to investigate the extent to which TBP was metabolised to 2,4,6-tribromoanisole (TBA) in dietary exposed zebrafish, and the amounts of TBP and TBA found in offspring. After 6 weeks of exposure, we found about 3% of the daily dose of TBP in adult fish and the mean concentration of TBA was 25-30% of the TBP concentration. TBP and TBA were detected in offspring with ...
NIH Funding Opportunities and Notices in the NIH Guide for Grants and Contracts: Characterization of the Adolescent Reproductive Transition (R21 Clinical Trial Optional) PA-18-045. NICHD
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TY - JOUR. T1 - Effect of previous lambing date and subsequent month of mating on reproductive performance in Mule ewes. AU - Mitchell, L M AU - King, Michael. AU - Aitken, Raymond. AU - Wallace, Jacqueline. PY - 1999/8. Y1 - 1999/8. N2 - The objective was to determine the effect of previous lambing date and subsequent month of mating on reproductive performance in Mule (Bluefaced Leicester X Scottish Blackface) ewes. Sixty-four ewes which had previously lambed in January (13 January (s.e. = 1 day)) and 80 ewes which had previously lambed in May (15 May (s.e. = 1 day)) were allocated equally to four mating periods (30 August to 17 September, 1 November to 19 November, 3 January to 21 January and 14 February to 4 March) in a 2 X 4 factorial design. From 20 days before and during their designated mating period, January- and May-lambing ewes were separately housed in straw-bedded pens under natural photoperiod and were given 1 kg per head per day dried grass pellets. A-vasectomized ram was ...
Answer (1 of 1): Basically in eukaryotic reproduction cycle , the asexual reproduction involves mitosis only while the sexual reproduction involves meiosis and syngamy. Both of these processes are the counterparts of each other thats why both of them are required in the sexual reproduction. Meiosis and Syngamy, together make the reproduction process a cycle|. In the meiosis phase, the cells are gone through the cell division and get haploid number of chromosomes. The process of reproduction is completed when the two gametes are fused in the syngamy phase. In this way both of these processes are must in the completion of the reproduction cycle.
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TY - JOUR. T1 - Mechanisms associated with an advance in the timing of seasonal reproduction in an urban songbird. AU - Fudickar, Adam M.. AU - Greives, Timothy J.. AU - Abolins-Abols, Mikus. AU - Atwell, Jonathan W.. AU - Meddle, Simone L.. AU - Friis, Guillermo. AU - Stricker, Craig A.. AU - Ketterson, Ellen D.. N1 - Funding Information: We would like to thank Alexander Kauffman at UCSD for use of lab space and equipment and Tim Gentner at UCSD for serving as our representative to the IACUC. John McCormack and Brant Faircloth assisted with sequencing of the junco reference genome and provided support to GF. Jessica Graham, Emily Stewart, Katie Needham, Rachel Hanauer, Alex Hughes, Abby Kimmitt, Sam Slowinski, and Charli Taylor helped to collect and process samples. This work was funded by the National Science Foundation (IOS-1257474 to EK and IOS-1257527 to TG). SM acknowledges Roslin Institute strategic grant funding from the Biotechnology and Biological Sciences Research Council ...
Species-specific strategies for financing the costs of reproduction are well understood, forming a continuum ranging from high to low reliance on stored nutrients. Animals relying mostly on stored reserves are termed capital breeders, whereas income breeders rely mostly on concurrent intake when financing the costs of reproduction. The role and adaptive value of individual variation in these strategies remain elusive. Life-history theory posits that capital breeding should be favoured when offspring reproductive value peaks, typically occurring early in the season, and that current income should increasingly be used with progressing season. Because resource limitation may hamper flexible resource allocation, a corollary prediction is that only good-condition individuals may show the expected seasonal shift in resource use. To test this prediction, we examined stable isotopes (δ13C and δ15N) in blood and lipid-free egg yolk of breeding eider females (Somateria mollissima) from the Baltic Sea to
Prenatal and preimplantation testing technologies have offered unprecedented access to information about the genetic and congenital makeup of our prospective progeny. Future developments such as preconception testing, noninvasive prenatal testing, and more extensive preimplantation testing promise to increase that access further still. The result may be greater reproductive choice, but it also increases the burden on women and men to avail themselves of these technologies in order to avoid having a child who has a disability. The overwhelming question for legislators has been whether and, if so, how to regulate the use of these technologies in the face of compelling but seemingly contradictory claims about the advancement of reproductive choice and the dangers of eugenic or discriminatory effects. This book examines the evolution of this legislative oversight across a number of jurisdictions and explores the tensions and ambiguities that inform these laws. ...
Background Genes involved in male reproduction are often the targets of natural and/or sexual selection. SCML1is a recently identified X-linked gene with preferential expression in testis. To test...
Summary - The reproduction of Radopholus similis isolates from different origins and hosts was compared in carrot disk cultures at different temperatures. At 15°C, only the isolates collected from ornamental plants in Europe reproduced. The greatest fecundity was observed at 25°C. The reproduction factor (final population/initial population: Pf/Pi) ranked the isolates in similar order for four of the temperatures studied (15, 20, 25 and 30°C). When carrot discs at 28°C were inoculated with single females of isolates selected from those with different reproductive factors, this ranking was confirmed. This suggests that reproduction is controlled by intrinsic isolate characteristics which are not influenced by temperature. Isolates with most reproduction had a greater percentage of reproductive females than isolates with less reproduction, associated with a high ratio of females : males and a high proportion of females in the total production. The mean offspring per productive female was similar for
reproductive system - Reproductive Cells and Gonads - The basic organs of sexual reproduction are the gonads, which are ovaries in females and testes in males. The gonads are dormant until they are activated by hormones at sexual maturity. (See also Sexuality.)The male gametes, called spermatozoa or sperm, are produced in the testes. Spermatozoa are microscopic tadpole-shaped cells with long tails. In all invertebrates the testes are internal, but in most mammals, including humans, they lie in an external sac called the…
This one-generation study assessed the potential of esterified propoxylated glycerol (EPG) to affect reproduction and offspring development in rats. Male and female Crl:CD(SD)BR rats (30/sex/group) were exposed to EPG at 0, 0.5, 1, and 2g/kgbw/day or at 5% (w/w) in the diet prior to (13weeks), during, and after two consecutive matings. For dams, exposure continued through gestation and lactation; F1a and F1b pups were weaned to the respective diet (for up to 91days).
The peculiar bone histology of Myotragus provides direct evidence of the developmental and growth strategy and indirect evidence regarding the physiology of this insular dwarf mammal. The presence of lamellar-zonal bone throughout the cortex indicates that Myotragus grew at slow and variable rates and ceased growth cyclically, which was associated with an important delay in the attainment of skeletal (sexual) maturity. Consistent with life history theory (30), the extended juvenile development of Myotragus was associated with an extended life span as indicated by the elevated number of very old individuals in the fossil assemblages (10). Our empirical finding, hence, does not support the prediction that life history traits of insular dwarfs accelerate to increase reproductive investment (12-15), but instead lends support to the model that predicts a shift in life history traits toward the slow end of the slow-fast continuum with a delay in age at maturity and an extended life span (16).. True ...
Our data provide no evidence that positive selection is enhanced in sympatry, and if these candidate GRPs are involved in prezygotic isolation, we have no evidence for enhanced prezygotic isolation. The polymorphism statistics likewise give no indication that RCD is occurring in these three proteins.. We cannot necessarily conclude from lack of evidence for RCD in CIPRO37.40.1, CIPRO60.5.1 and CIPRO100.7.1 that RCD is not occurring in this system. If enhanced prezygotic isolation between Type A and B does exist, there are several reasons why we might not have detected it in this study. First, primers for candidate GRPs were developed from the Type A genomic sequence and were used to amplify and sequence both Type A and B individuals (the Type B genome has not been sequenced). But Type A and B are substantially divergent (p-distances: 0.124 at mtCOI, 0.035 to 0.116 for six nuclear loci; [43]), which could explain why 15 genes encoding GRP candidates could not be successfully amplified and/or ...
Looking for online definition of net reproductive rate in the Medical Dictionary? net reproductive rate explanation free. What is net reproductive rate? Meaning of net reproductive rate medical term. What does net reproductive rate mean?
Tags: Mirela petrean album 2013, Bug out vehicle loadout, Asexual Reproduction PowerPoint Presentation Lesson Plan. Natural Vegetative Propagation, Artificial Vegetative Propagation. $ Asexual Reproduction In Animals Vegetative Reproduction Teacher Resources Biology Presentation Life Science Science Lessons Activities Education. Sexual and Asexual Reproduction Concept Sort. Apr 12, · Asexual vs Sexual Reproduction 1. Asexual vs. Sexual Reproduction Note: If you are viewing this PPT at home, some videos may not play. 2. Asexual Reproduction• Asexual reproduction is the process by which a single organism produces genetically identical offspring.•. Methods of Reproduction Sexual and Asexual Reproduction Asexual Reproduction: requires only 1 parent and the offspring are an exact copy of the parenta clone Asexual Reproduction: Organisms that reproduce asexually cannot develop much variety, . Reproduction Sexual Reproduction Asexual Reproduction Asexual Reproduction: Genetically Identical ...
Handbook of drug therapy in reproductive endocrinology and infertility , Handbook of drug therapy in reproductive endocrinology and infertility , کتابخانه دیجیتال دانشگاه علوم پزشکی اصفهان
It is interesting to note that all bone and weight gains seen in paired female mole-rats appeared several weeks after removal from reproductive suppression and became statistically discernible from males or controls approximately 6-10 weeks after colony separation. This is most likely because small increases in growth need to accumulate to be observable. This explanation was confirmed by the growth rate data, which can be a more sensitive index of subtle changes that are occurring in bone turnover. Although it took weeks to see the net increase in bone length, increased bone growth rates in paired females occurred during the 5-week block immediately after colony separation, and this growth rate peaked 10 weeks after colony separation. Therefore, growth mechanisms appeared to accelerate immediately after colony separation. The growth rate data demonstrated a pattern that consisted of an initial sharp increase and asymptote in growth, with elevated growth rates continuing for several weeks before ...
4. The type of division, in which two individuals are formed from a single individual, is … Budding 3. The segments rapidly grow new cells to constitute their muscle fiber and internal structure through mitosis. These are binary fission, budding, vegetative reproduction, fragmentation and by spores. Segmented worms and many echinoderms such as starfish reproduce asexually via fragmentation. Organisms produced by asexual reproduction are the product of mitosis. There are two types of reproduction - sexual reproduction and asexual reproduction. Asexual reproduction is the primary form of reproduction for single-celled organisms such the archaea, bacteria, and protists. Natural selection, the mechanism for evolution, chooses which traits are favorable adaptations for a given environment and which are unfavorable. A particular type of cell known as a gemmule can develop into a new organism. But in the long term (over several generations), lack of sexual reproduction compromises their ability to ...
Despite being listed as endangered on the IUCN (World Conservation Union) red list (Anon, 2006) and intense conservation efforts on its behalf, little is known about the reproductive biology of the Fijian ground frog (Platymantis vitianus). Breeding is important for species survival and hormones are the essence of reproduction. The certain aspects of captive breeding and reproductive endocrinology of P. vitianus is studied so that the basic reproductive patterns can be understood. The breeding of P. vitianus is being studied in a purpose built outdoor enclosure based at the University of the South Pacific (USP), Fiji Islands as an insurance policy while invasive species eradication work is on-going on Viwa Island (one of the five remaining mongoose [Herpestes javanicus] free island habitats of P. vitianus). Primary focus of captive breeding is to establish an ex-situ captive management strategy, egg-embryo management and monitoring the health status of P. vitianus. Under the ex-situ captive ...
The evolution and maintenance of sexual reproduction may involve important tradeoffs because asexual reproduction can double an individuals contribution to the gene pool but reduces diversity. Moreover, in social insects the maintenance of genetic diversity among workers may be important for colony growth and survival. We identified a previously unknown termite breeding system in which both parthenogenesis and sexual reproduction are conditionally used. Queens produce their replacements asexually but use normal sexual reproduction to produce other colony members. These findings show how eusociality can lead to extraordinary reproductive systems and provide important insights into the advantages and disadvantages of sex.. ...
We studied annual and lifetime reproductive success (LRS) of both sexes of common buzzard Buteo buteo in eastern Westphalia, Germany. We followed a bottom-up approach starting from individual breeding attempts, over lifetime reproductive success to derive population demography. Annual breeding performance and survival followed a quadratic relationship with breeding experience; individuals starting their breeding career were less likely to survive and breed successfully than birds of intermediate breeding experience. According to an analysis of selection gradients, both the opportunity and intensity of selection peaked in the early stages of the breeding career. The distribution of both LRS and another fitness measure, lambda, was highly skewed, with ca 17% of adult birds producing 50% of fledglings in both sexes. Besides breeding life span and number of breeding attempts, habitat quality and plumage morph were significant predictors of LRS. There were strong differences in LRS and lambda between ...
TY - JOUR. T1 - Identification of porcine Lhx3 and SF1 as candidate genes for QTL affecting growth and reproduction traits in swine. AU - Smith, T. P.L.. AU - Showalter, A. D.. AU - Sloop, K. W.. AU - Rohrer, G. A.. AU - Fahrenkrug, S. C.. AU - Meier, B. C.. AU - Rhodes, S. J.. PY - 2001. Y1 - 2001. N2 - The distal portion of the long arm of porcine chromosome 1 has been shown to harbour several quantitative trait loci affecting growth and reproductive traits in swine. In order to identify potential candidate genes that might underlie these effects, a comparative mapping analysis was undertaken to define the extent of orthologous segments of human chromosome 9. A microsatellite associated with heat shock protein (HSP) A5 was used to define the proximal boundary of the quantitative trait loci (QTL) region, which suggests the human orthologue of the gene(s) responsible for the observed effects lies between HSPA5 and the q arm telomere of human chromosome 9. Examination of this region revealed two ...
Robert Hermes, DVM, Ph.D.(born November 15, 1969 in Celle, Germany) is a veterinarian researcher at The Leibniz-Institute of Zoo and Wildlife Research in Berlin. He studied veterinary medicine at the Freie Universität Berlin. He completed a Ph.D. in reproductive management. Hermes was a member of the Indianapolis Zoo team, that accomplished the worlds first successful artificial insemination of an African elephant. He completed a postdoctoral research project concentrated on the reproductive management of African elephants. Hermes is a researcher at The Leibniz Institute for Zoo and Wildlife Research(IZW), in the department of reproductive management. His research concentrates on the reproductive management of elephants and rhinoceros. Hermes has supervised doctoral candidates researching reproductive management in a variety of animal species. Hermes is an integral member of the eminent IZW researchers in animal reproductive management. Dr. Thomas Bernd Hildebrandt, head of the IZW Department ...
Histology Of Female Reproductive System 18 Medical School Histology Female Reproductive System Part 3 photo, Histology Of Female Reproductive System 18 Medical School Histology Female Reproductive System Part 3 image, Histology Of Female Reproductive System 18 Medical School Histology Female Reproductive System Part 3 gallery
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Reproduction (or procreation or breeding) is the biological process by which new individual organisms - offspring - are produced from their parents. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism. Asexual reproduction is not limited to single-celled organisms. The cloning of an organism is a form of asexual reproduction. By asexual reproduction, an organism creates a genetically similar or identical copy of itself. The evolution of sexual reproduction is a major puzzle for biologists. The two-fold cost of sexual reproduction is that only 50% of organisms reproduce and organisms only pass on 50% of their genes. Sexual reproduction typically requires the sexual interaction of two specialized organisms, called gametes, which contain half the number of chromosomes of normal ...
TY - JOUR. T1 - Overexpression of transforming growth factor α in transgenic mice alters nonreproductive, sex-related behavioral differences. T2 - Interaction with gonadal hormones. AU - Hilakivi-Clarke, L.. PY - 1994. Y1 - 1994. N2 - Sexually dimorphic differences in voluntary sodium intake, locomotor activity, immobility in the swim test, and aggressive behavior were found to be altered in transgenic CD-1 mice that overexpressed transforming growth factor α (TGFα). In contrast to nontransgenic CD-1 mice, immobility in the swim test was longer and sodium intake higher in the male TGFα mice than in the female TGFα mice. These findings indicate that the male TGFα mice exhibited feminization of some behaviors. Furthermore, the male TGFα mice were highly aggressive. Castration reversed the behavioral effects in the adult male transgenic mice, but ovariectomy did not reverse the behavioral effects in the adult female transgenic mice. Thus the feminizing effect of TGFα on some nonreproductive ...
Kansas State University entomologists have helped identify a neuropeptide named natalisin that regulates the sexual activity and reproductive ability of insects.
Reproductive endocrinology & Infertility is an open access, peer-reviewed journal that publishes articles on all aspects of endocrinology & infertility.
FERTILITY AND STERILITY VOL. 82, NO. 5, NOVEMBER 2004 Copyright 2004 American Society for Reproductive Medicine Published by Elsevier Inc. Printed on acid-free paper in U.S.A. REPRODUCTIVE ENDOCRINOLOGY
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Asexual reproduction is the mode of reproduction in prokaryotes. In particular, prokaryotes reproduce through binary fission. Eukaryotes, especially higher forms of animals, reproduce through sexual means, i.e. by sexual reproduction. In sexual reproduction, gametes are produced by meiosis. A male gamete fertilizes the female gamete, forming a zygote. Some eukaryotes are capable of asexual reproduction. In asexual reproduction, the organism is capable of reproducing an offspring in the absence of a mate. As a result, the offspring is a clone of the parent and therefore results in low genetic variation in the species as a whole. Some species are capable of heterogamy, i.e. the ability to alternate between sexual and asexual reproduction. ...
Considerable information is available on the reproductive function of goats, but research on reproductive management of goats in the U.S. has focused mostly on milk and fiber production systems and has not been directed at meat as the primary product. In a meat production system, however, reproductive performance is of paramount importance since productivity is largely a function of the number of offspring born and weaned and the frequency with which they are produced.
Reproduction. Scope Note Narrower Term: Cattle Reproduction Narrower Term: Cell nuclei Transplantation Narrower Term: Conjugation (Biology) See Also: Embryology Narrower Term: Fertility Narrower Term: Fertilization (Biology) Narrower Term: Fetus Narrower Term: Gametogenesis See Also: Generative organs Narrower Term: Gynogenesis Narrower Term: Human reproduction Narrower Term: Isolating mechanisms Narrower Term: Ovulation Narrower Term: Paedogenesis Narrower Term: Parthenogenesis Narrower Term: Parthenogenesis in animals Narrower Term: Parturition Narrower Term: Pregnancy Narrower Term: Sexual cycle Narrower Term: Spawning Narrower Term: Spontaneous generation See Also: Theriogenology Narrower Term: Viruses Reproduction Narrower Term: Viviparity Narrower Term: Domestic animals Reproduction Narrower Term: Livestock Reproduction Narrower Term: Bacteriophage mu Reproduction Narrower Term: Oncogenic DNA viruses Reproduction Narrower Term: Herpes simplex virus Reproduction Narrower Term: Herpesviruses ...
ALCOHOLS EFFECTS ON FEMALE REPRODUCTION. The following section details alcohols effects on puberty, the female reproductive system, and postmenopause, as revealed by human and animal studies.. Alcohol and Puberty. Rapid hormonal changes occurring during puberty make females especially vulnerable to the deleterious effects of alcohol exposure during this time. Thus, the high incidence of alcohol consumption among middle school and high school students in the United States is a matter of great concern. A national survey of students revealed that 22.4 percent of 8th graders and 50 percent of 12th graders reported consuming alcohol in the 30 days before the survey (Johnston et al. 2001). Little research on the physiological effects of alcohol consumption during puberty has focused on human females. However, one study found that estrogen levels were depressed among adolescent girls ages 12 to 18 for as long as 2 weeks after drinking moderately (Block et al. 1993). This finding suggests the ...
TY - JOUR. T1 - Metabolic, endocrine, and reproductive changes of a woman channel swimmer. AU - Frisch, Rose E.. AU - Hall, George M.. AU - Aoki, Thomas T.. AU - Birnholz, Jason. AU - Jacob, Robert. AU - Landsberg, Lewis. AU - Munro, Hamish. AU - Parker-Jones, Kirtly. AU - Tulchinsky, Dan. AU - Young, James. PY - 1984/12. Y1 - 1984/12. N2 - We report the coordinated metabolic, hormonal, and reproductive data of a female channel swimmer during the pre-swim training period, immediately post-swim, and in the post-swim untrained state. Urine and blood samples collected at these times were assayed for diurnal urinary catecholamines, urinary C-peptide and 3-methylhistidine, total blood ketone bodies, glycerol, the reproductive hormones, adrenal androgens, and thyroid hormones. Subcutaneous fat was measured by ultrasonography. All of the metabolic and hormonal data post-swim except cortisol reflected the severe physiological stress. Urinary catecholamines returned to near-normal levels by 12 hours ...
Translocation of mothers with dependent calves is ill-advised, especially when restocking. Interestingly, there was a sex-differential risk when using juvenile and young adults to restock populations. These may have important implications for sex- or age-biased translocation strategies designed to reduce the impact of harvest on the source population or maximize productivity after release. Juvenile, but not young adult, females had high post-release mortality. The reverse was true for males where juvenile males did not feature in mortality statistics but were a large portion of young adult deaths.. Sex differential mortality amongst juvenile and young adult age classes might be due to sex differences in age at first reproduction because it is a high-risk period in a large polygynous vertebrates life. Female black rhinoceros attract the sexual interest of bulls at their first oestrous around 3·5 years of age (first parturition between 4·8 and 5·3 years, Schenkel & Schenkel-Hulliger 1969; and ...
Austin Journal of Environmental Toxicology is an open access, Scholarly journal dedicated to publish articles in all areas of Environmental Toxicology.
Dr. Mark P. Leondires is the Founder, Medical Director and Partner in reproductive endocrinology at Reproductive Medicine Associates of Connecticut (RMACT) and Gay Parents To Be (GPTB). He is board-certified in both Obstetrics and Gynecology and Reproductive Endocrinology and Infertility. Board-Certified Reproductive Endocrinologist: Infertility Doctor - Connecticut & New York For Dr. Mark Leondires, medicine offers an opportunity to solve problems; each fertility patient presents a unique puzzle. This, combined with a wide range of interests and life events, is how Dr. Leondires came into reproductive endocrinology and infertility and to start his own fertility practice. From the beginning, as one of four children born to his Greek-immigrant parents, Dr. Leondiress environment has infiltrated and shaped the person he would become. In his early years, Dr. Leondires was raised with a prideful interest of ancient history and architecture, rooted in Greek contributions. This eventually led to a ...
View Notes - Chapter 36 Animal Reproduction from BIOL 1006 at Virginia Tech. Chapter 36 Animal Reproduction Vocabulary Acrosome sac at the head of sperm containing enzymes to allow the sperm to
Costs of reproduction are an integral and long-standing component of life-history theory, but we still know relatively little about the specific physiological mechanisms underlying these trade-offs. We experimentally manipulated workload during parental care in female European starlings (Sturnus vulgaris) using attachment of radios and/or wing clipping and assessed measures of workload, current breeding productivity, future fecundity, and survival (local return rate) in relation to treatment. Females with wing clipping and radio attachment paid a clear cost of reproduction compared with all other treatment groups: they had lower future fecundity and lower return rates despite having lower current breeding productivity. We then measured 13 physiological traits, including measures of aerobic/metabolic capacity, oxidative stress and muscle damage, intermediary metabolism and energy supply, and immune function. Our results show that the cost of reproduction in females with wing clipping and radio ...
One of the key tenets of life-history theory is that reproduction and survival are linked and that they trade-off with each other. When dietary resources are limited, reduced reproduction with a concomitant increase in survival is commonly observed. It is often hypothesized that this dietary restriction effect results from strategically reduced investment in reproduction in favor of somatic maintenance to survive starvation periods until resources become plentiful again. We used experimental evolution to test this waiting-for-the-good-times hypothesis, which predicts that selection under sustained dietary restriction will favor increased investment in reproduction at the cost of survival because good-times never come. We assayed fecundity and survival of female Drosophila melanogaster fruit flies that had evolved for 50 generations on three different diets varying in protein content-low (classic dietary restriction diet), standard, and high-in a full-factorial design. High-diet females ...
TY - JOUR. T1 - Photoperiod. T2 - Its importance as an impeller of pineal and seasonal reproductive rhythms. AU - Reiter, R. J.. PY - 1980/3/1. Y1 - 1980/3/1. N2 - A number of long day breeding rodents depend on seasonal changes in photoperiodic length to synchronize their breeding seasons with the appropriate time of the year. These relationships are particularly conspicuous in the Syrian hamster where day length is vitally important in determining periods of sexual activity and inactivity. The organ in the body whose activity is most closely attuned to the photoperiodic environment is the pineal gland. During periods of darkness the biochemical and secretory activity of the pineal is enhanced with the resultant production of antigonadotrophic principles which are strongly suppressive to reproductive physiology. In this manner, decreasing day lengths of the fall are involved with suppressing sexual capability in male and female hamsters. Throughout the winter months darkness (because of the ...
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The Fertilome Test is the first multigene panel test for womens risk of reproductive conditions approved by the NY State Department of Health
Jun 08, · For plants that rely on sexual reproduction, the maturity process for a crop yield can be several months. This shortened growing time makes it possible for multiple yields in some environments. What Are the Disadvantages of Asexual Reproduction? 1. Negative mutations linger longer in asexual . Jan 28, · Asexual reproducers do not have to carry their offspring for a long amount of time and produce more than one at a time. This makes it a quick and inexpensive process for them in the terms of time. The Disadvantages of Asexual Reproduction. 1. No Diversity Since the traits of only one parent is passed on, all of the offspring are exactly.. Disadvantages of sexual reproduction and asexual reproduction in Long Beach
The swine herd in this research was located in Chiang Mai province, Northern Thailand (latitude 18° 47′ 43″ North and longitude 98° 59′ 55″ East). The climate of the area is tropical, with average temperature ranging from 17°C to 35°C, average relative humidity ranging from 37% to 99%, and average rainfall ranging from 880 mm to 1,457 mm over the last thirteen years [10]. Seasons were defined as winter (November to February), summer (March to June), and rainy season (July to October). Gilts and sows were housed in an open-house system with water dripper, sprinkler, and fans, while boars were kept in an enclosed barn with an evaporative cooling system. Boars were fed 2.5 kg/d of feed with 16% crude protein and 3,200 to 3,500 kcal/kg. Sows received rations of different composition depending on the status of their reproductive cycle. Gilts and non-lactating sows were fed 2.5 kg/d of feed with 16% crude protein and 3,200 to 3,500 kcal/kg of energy. Nursing sows were fed 5 to 6 kg/d of ...
Reproduction is influenced by the physiological and environmental modulation of the hypothalamic gonadotropin-releasing hormone (GnRH) neuronal network. GnRH hypothalamic activity is reflected in the systemic circulation by its downstream effector, luteinising hormone (LH). During stress, the GnRH-dependent LH activity that is required for adequate gonadal development and function is suppressed by glucocorticoids secreted by the adrenal glands. Emerging research in the field of stress-induced infertility show glucocorticoids do not directly inhibit GnRH activity and instead may act via the inhibitory RFamide-related peptide (RFRP) neurons, which suppress GnRH secretion. Thus far, this intermediary inhibitory role of RFRP neurons between the stress and reproductive axes is mainly supported by the upregulated expression of hypothalamic RFRP activity with stress in both sexes. Using a transgenic mouse model, the experiments in this thesis examine whether hypothalamic RFRP neuronal signalling is ...
Are you two twins? Asexual Reproduction: Asexual Reproduction: -Used by many unicellular organisms, plants, and lower animals. -Involves only mitotic cell division = each offspring has exactly the same heredity as its parent. -Usually rapid compared to sexual reproduction. Types of Asexual Reproduction Include:
Invitation to join the Plant Reproduction listserv ---------------------------------------------------- Under supervision of the International Association of Sexual Plant Reproduction Research (IASPRR) an Internet list service is opened for scientists studying plant sexual reproduction of higher plants. With this list a communication by E-mail is possible among all subscribers of the list. Such list offers for example the opportunity: to exchange scientific -knowledge, ideas -information, questions to announce -congresses, books, courses -jobs, projects -information of the IASPRR, Journal Sexual Plant Reproduction The list owner is the secretary of the IASPRR, there is no archive of the messages. This mail invites you to join the list. In case you know other interested scientists, invite them to subscribe also. Subscription to PLANT-REPR list ------------------------------- Scientists with an e-mail number can send a message to: listserv at message: sub plant-repr your name You ...
For studying the influence of feed and temperature on gonad growth and maturity of the baby clam Marcia opima, experiments were conducted for 45 days at temperatures of 23°C and 28°C. The progress of gonadal recovery was followed by periodic determination of gonadosomatic index, condition index, digestive gland index and oocyte diameter. There was significant difference in the gonadosomatic index between fed and unfed clams at 23°C and 28°C. No significant difference in the gonadosomatic index was noted in the fed treatments at 23°C and 28°C, but the time of conditioning had significant influence on the gonadosomatic index. A significant relationship was found between the gonadosomatic index and condition index of the clams in all the treatments. ...
State Standard 2E. Compare the advantages of sexual reproduction and asexual reproduction in different situations. Meiosis & Sexual Reproduction (10.1)
Abstract: Heritablities and correlations were estimated between lamb body weight at different ages and reproductive traits in the Lori-Bakhtiari sheep breed. Data and pedigree information for Lori-Bakhtiari sheep used in this study were 5826 records of body weight of lambs from 240 sires and 1627 dams, and 5741 records of reproductive traits from 1797 ewes collected from 1989 to 2006 from a Lori-Bakhtiari flock at the Shooli station in Shahrekord. The lamb traits investigated were weights at birth (BWT), weaning (WWT) and at six months of age (WT6). The reproductive traits were conception rate (CR), litter size at birth per ewe lambing (LSB/EL), litter size at weaning per ewe lambing (LSW/EL), litter size at birth per ewe exposed to a ram (LSB/EE), litter size at weaning per ewe exposed (LSW/EE), total litter weight at birth per ewe lambing (TLWB/EL), total litter weight at weaning per ewe lambing (TLWW/EL), total litter weight at birth per ewe exposed (TLWB/EE) and total litter weight at ...
ABSTRACT. In Mexico City, Chapultepec Zoo is working together with the Zoological Society of San Diego and Ueno Zoo in Japan on the improvement of assisted techniques for the reproduction of the Giant Panda (Ailuropoda melanoleuca) a highly endangered species native to the Peoples Republic of China.. The Giant Panda is a seasonally monoestrus species in which the estrus lasts from 9 to 11 days, spontaneously ovulating and being sexually receptive for only 2 or 3 days. In Mexico the Giant Panda females have presented an estrus peak within mid February until mid April. Therefore, accurate monitoring of the estrus cycle to pinpoint the time of ovulation is critical for the timed mating or artificial insemination. Monitoring estrogen (E1G) and progesterone (PdG) in a non-invasive way indicates hormonal changes that are continuously evaluated and corroborated with modifications on the vaginal cytology and behavior, as well as to confirm or discard pregnancy and to predict birth time.. Hormone ...
Billy Kim is currently the Embryology Technical Supervisor and is certified through the American Association of Bio Analysts. He holds an earned BSc, MSc, and PhD about Animal Reproductive Science at the Kangwon National University in South Korea. He completed his post-doctoral researcher and fellowship supported NIH training in reproductive sciences training grant at Division of Reproductive Endocrinology and Infertility, Department of Reproductive Medicine, University of California San Diego. He has studied regulation of Hypothalamic-Pituitary-Gonadal axis on reproductive endocrinology. Recently he also published research papers about the Role of Oxidative Stress in gonadotropin release hormone signal pathway. He has published over 22 research papers in the field of reproductive biology. He worked as an embryologist at Houston Fertility Institute in Texas as a senior embryologist before joining Carolina Conceptions. He is highly skilled in all aspects of IVF procedures including egg ...
Appraisal of reproductive strategy and fecundity is necessary to evaluate the reproductive potential of individual fish species. To estimate reproductive potential, one needs to consider a variety of attributes including onset of maturity, fecundity, atresia, duration of reproductive season, daily spawning behaviour and spawning fraction. In this contribution, we review several methods currently used to estimate fecundity of marine fishes collected in the field in relation to their reproductive strategy. The advantages and disadvantages of each method are provided. Requirements are given to appropriately sample gonadal tissue that will enable researchers to establish incidence of sexual maturity and estimate fecundity ...
Reproduction[edit]. Gestation Period Young per Birth Sexual Maturity Life Span 180-210 days 1-7 Does: 7-8 months 10-12 years ...
Reproduction[edit]. Pickerel frogs typically emerge from hibernation around mid April with the majority of the frogs arriving ...
Sexual reproduction[edit]. Most barnacles are hermaphroditic, although a few species are gonochoric or androdioecious. The ... The sessile lifestyle of barnacles makes sexual reproduction difficult, as the organisms cannot leave their shells to mate. To ...
"Octopuses and Relatives: Reproduction". A Snail's Odyssey. Retrieved 11 April 2017.. *^ a b c "Giant Pacific Octopus ( ... The reproduction of octopuses has been studied in only a few species. One such species is the giant Pacific octopus, in which ... Octopus lifespan is limited by reproduction: males can live for only a few months after mating, and females die shortly after ... Aristotle noted that the octopus had a hectocotyl arm and suggested it might be used in sexual reproduction. This claim was ...
Reproduction[edit]. Main article: Conifer cone. Most conifers are monoecious, but some are subdioecious or dioecious; all are ... Conifer reproduction is synchronous with seasonal changes in temperate zones. Reproductive development slows to a halt during ...
Reproduction[edit]. Information regarding the African pygmy squirrel's reproduction has not been fully defined. Generally ... Asdell's patterns of mammalian reproduction: a compendium of species-specific data: i-viii, 1-1023 ...
Reproduction[edit]. Females give birth to up to 12 young at a time. Newborns are about 15 cm (5.9 in) in total length. [7] ...
Reproduction[edit]. Female with calf. Captive males breed at five years of age, but wild males attain dominance much later when ...
Mating and reproduction[edit]. Kangaroo rats have a promiscuous mating system. Their reproductive output is highest in summer ...
Reproduction[edit]. The adult female gives birth to one or two litters per year, and the breeding pair is monogamous. The pair ... As a tropical animal, reproduction is not fixed to certain times of year, and takes place twice yearly. The reproductive period ...
Reproduction and development[edit]. House centipedes lay their eggs in spring. In a laboratory observation of 24 house ...
Reproduction[edit]. The breeding season is between June and January. The gestation/pregnancy of a female is 18 days.[6] The ...
Origin of sexual reproduction[edit]. Further information: Evolution of sexual reproduction. Eigen et al.[76] and Woese[77] ... One of the challenges in studying abiogenesis is that the system of reproduction and metabolism utilized by all extant life ... The cycle of haploid reproduction, with occasional fusion to a transient diploid state, followed by splitting to the haploid ...
Reproduction[edit]. See also: Dolphin § Reproduction and sexuality. Gestation requires an estimated 13-14 months, at intervals ...
Reproduction[edit]. Actinomycetales have 2 main forms of reproduction; spore formation and hyphae fragmentation. During ... reproduction, Actinomycetales can form conidiophores, sporangiospores, and oidiospores. In reproducing through hyphae ...
Effects on reproduction[edit]. During the first two weeks after fertilization, radiation therapy is lethal but not teratogenic. ... Human Reproduction Update. 7 (4): 394-403. doi:10.1093/humupd/7.4.394. PMID 11476352.. [1] ...
Reproduction and parenting[edit]. Adult with offspring clinging to her back. Giant anteaters can mate throughout the year.[14] ...
Reproduction[edit]. There is limited information on the reproductive habits of this snake. Like many elapids, many-banded ...
Reproduction[edit]. A male is referred to as a dog, and the female as a vixen. They are very similar in appearance, though dogs ...
Females may try to increase their reproduction success by mating with males outside their family groups. When copulation is ...
3.2 Reproduction. *4 Evolution. *5 Conservation *5.1 Platypus in wildlife sanctuaries *5.1.1 Queensland ...
Guide to copies reproductions restrikes originals etc[edit]. I recall an explanatory page somewhere on the interwebs, giving ... The modern repro, while probably more similar in colour to a theoretical "original", is clearly of a much lower quality, with ... See also my request above at #Guide to copies reproductions restrikes originals etc.. HTH. Quiddity (talk) 00:16, 14 August ... It is currently a modern(ish) reproduction (File:Great_Wave_off_Kanagawa2.jpg) but close comparison with the JP1847 print (File ...
Reproduction[edit]. Females are observed to mate at about 3 years of age. During time of mating, the sun bear shows behaviours ...
Reproduction and growth[edit]. The false scad reaches sexual maturity during its second year of life at a length of around 20 ...
Life cycle and reproduction[edit]. The life cycle of D. heteracantha are not tied to the seasons. They can live for up to two ...
Sex and reproduction[edit]. Whether accurately or not, Auel has incorporated sex into her prehistoric culture in a number of ...
Evidence based on the fossil record, serology, karyology, behavior, anatomy, and reproduction reflect closer affinities with ...
Reproduction[edit]. Ratites are different from the flying birds in that they needed to adapt or evolve certain features to ...
Reproduction[edit]. Hatchling specimen known as "baby Louie". Several oviraptorosaurian nests are known, with several ...
Reproduction[edit]. The breeding colony in Montagu, Western Cape, South Africa. The species usually breeds once per year in the ...
Human reproduction is any form of sexual reproduction resulting in human fertilization, typically involving sexual intercourse ... Human reproduction normally begins with copulation, followed by nine months of pregnancy before childbirth, though it may be ... Human reproduction naturally takes place as internal fertilization by sexual intercourse. During this process, the male inserts ... Sexual Reproduction in Humans. 2006. John W. Kimball. Kimballs Biology Pages, and online textbook. ...
Bill Nye talks about the realities of reproduction, and the right wing completely loses its shit. It is not Nye at his most ... By 2008, she had started laying eggs and the pair had multiple litters of offspring through sexual reproduction. After her mate ... They discovered that male roundworms can send two kinds of pheromones that prime females for reproduction. One type of ... revealed a remarkable finding about the costs of reproduction in orcas. Older mothers tend to spend more time taking care of ...
... is the primary method of reproduction for the vast majority of macroscopic organisms, including almost all ... Sexual reproduction is characterized by processes that pass a combination of genetic material to offspring, resulting in ... Alternatively, sexual reproduction may allow for the "ratcheting" of evolutionary speed as one clade competes with another for ... The evolution of sexual reproduction is a major puzzle. The first fossilized evidence of sexually reproducing organisms is from ...
Third-party reproduction or donor-assisted reproduction is any human reproduction in which DNA or gestation is provided by a ... 3] Various articles on Third Party Reproduction. *[4] Third-Party Reproduction, A Comprehensive Guide. Editor. Goldfarb, James ... Third-party reproduction is used by couples unable to reproduce where they would otherwise be unable to do so, by same-sex ... Annotated Bibliography for Children and Parents of Third Party Reproduction Compiled by the Education Committee, Spring 2007 ...
Each proglottid contains a complete set of male and female reproductive organs that produce the sex cells. Fertilization is internal; in most species cross fertilization between two adjacent worms is necessary, but in a few species self-fertilization may occur between two proglottids of the same worm, or within the same proglottid. In some species the fertilized eggs are shed continuously and leave the hosts body in the feces; in others the fertilized eggs are stored until the proglottid is filled with them and the entire proglottid is then shed. The eggs develop into embryos with a hard outer shell; these do not hatch until they are eaten by a suitable intermediate host.. ...
... formerly known as Sexual Plant Reproduction) is a journal devoted to publishing high-quality research in the field of ... Plant Reproduction (formerly known as Sexual Plant Reproduction) is a journal devoted to publishing high-quality research in ... Biotechnological applications in reproduction. Studies in model organisms where mechanisms of reproduction can be supported by ... Bridging the GAPs in plant reproduction: a comparison of plant and animal GPI-anchored proteins Authors. *Nicholas Desnoyer ...
Reproduction: Many advanced artiodactyls have elaborate courtship behaviour, a regular component of which is for the male to ... Reproduction. Many advanced artiodactyls have elaborate courtship behaviour, a regular component of which is for the male to ...
Sexual reproduction: Plasmogamy, the fusion of two protoplasts (the contents of the two cells), brings together two compatible ... In fungus: Sexual reproduction. Plasmogamy, the fusion of two protoplasts (the contents of the two cells), brings together two ...
However, this is enough to severely impact the reproduction of clownfish. ... Their future reproduction will be inhibited. Impacts of artificial light could spread to other reefs, while attracting young ... In fact, in this study, the researchers found that impacts on clownfish reproduction disappeared as soon as they returned the ... Now, scientists have confirmed that clownfish reproduction is stopped by artificial light. ...
Having a hard time getting pregnant? When is it an underlying health problem? Get additional information on the signs of infertility and when to see a doctor.
AsexualAsexual reproduction occurs when a new organism is produced from just one parent. It is a form of reproduction that does ... Source for information on Reproduction, Asexual: U*X*L Complete Life Science Resource dictionary. ... Reproduction is the process by which new organisms are produced from existing ones. Asexual reproduction means reproduction ... Asexual Reproduction , Sexual reproduction involves the production of new cells by the fusion of sex cells (sperm and ova) to ...
... photographic reproductions and microform. Springer may use the article in whole or in part in electronic form, such as use in ...
After the spider plant becomes root bound in the pot, reproduction starts and the spider plant has babies. ...
The division of a bacterial cell into two daughter cells is an example of asexual reproduction. Asexual reproduction is not, ... The known methods of reproduction are broadly grouped into two main types: sexual and asexual. In asexual reproduction, an ... In sexual reproduction two individuals a male and a female are required . ... each individual organism exists as the result of reproduction. ... Reproduction is the biological process by which new individual ...
Reproduction in which new individuals are produced from a single parent without the formation of gametes. It occurs chiefly in ... Reproduction, Asexual. Although sexual reproduction is more frequent, asexual reproduction also commonly occurs in the plant ... Asexual reproduction. Resources Sexual reproduction involves the production of new cells by the fusion of sex cells (sperm and ... Asexual reproduction. Sexual reproduction involves the production of new cells by the fusion of sex cells (sperm and ova) to ...
The Reproduction Research is located in Clay Center, NE and is part of the Plains Area.. The Acting Research Leader is Gary ... REPRODUCTION RESEARCH UNIT. P.O. BOX 166 (State Spur 18D)/USDA-ARS-PA-MARC. Clay Center, NE 68933. ... Research on reproduction includes both sexes and involves physiology, endocrinology, behavior, molecular biology, ... The primary efforts of the Reproduction Research Unit are directed toward improving the reproductive efficiency of beef cattle ...
... News that a woman has given birth via an ovary frozen when she was nine years old is just one ...
By learning when and where key species spawn, researchers hope to develop species-specific reproductive studies that will help fisheries managers develop strategies that protect spawning populations.
Listen to songs from the album Reproduction, including Parking Lot, Katydid, Kindergarten, and many more. Buy the album ...
Obesity and reproduction. BMJ 2006; 333 doi: (Published 30 November 2006) Cite ...
PHYSIOLOGY OF REPRODUCTION. Br Med J 1956; 1 doi: (Published 24 March 1956) Cite this as ...
Reproduction. [Ian Williams] -- Felicia, a nineteen-year-old student from a Caribbean family, and Edgar, the lazy-minded and ... I thought you might be interested in this item at Title: Reproduction Author: Ian ...
ReproductionGametogenesis in Plants and AnimalsRegulation of Gene Expression in Prokaryotes and Eukaryotes Sexual reproduction ... Sexual reproduction is the union of male and female gametes to form a fertilized egg, or zygote. The resulting offspring ... 2004 by Glen E. Moulton, Ed.D.. All rights reserved including the right of reproduction in whole or in part in any form. Used ...
... : Find phone numbers and addresses of companies from your area in the Infobel Directory, Australia, Infobel.Au, ...
Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by Society for Science & the Public, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education.. ...
Reproduction Services Know University of Washington Libraries staff are working remotely. All reproduction services are ... Reproduction, use and publication is governed by law and subject to permission. All reproductions regardless of format are ... Review Reproduction Price List. Additional fees are charged for special handling and postal service. Contact Special ... Reproduction services are available for audio and moving image items held in Special Collections for research and educational ...
Asexual reproduction is the most ancient mode of reproduction and is observed in representatives of all phyla of modern Metazoa ... 4. Asexual Reproduction in Adults. Asexual reproduction in adult holothurians occurs as transverse fission (architomy) and ... J. Lee, S. Uthicke, and M. Byrne, "Asexual reproduction and observations of sexual reproduction in the aspidochirotid sea ... 9. Factors That Influence Asexual Reproduction. The intensity of asexual reproduction varies greatly between populations of the ...
Or log in to play for credit.. This activity is tracked by Mr. Jeffords. If you are in Mr. Jeffordss class, please log in for credit:. ...
Reproduction, use and publication is governed by law and subject to permission. All reproductions regardless of format are ... Oversized Materials Reproduction Request for items larger than 11" x 17". Print, complete and sign form. Deliver to Special ... Print, complete and sign reproduction request and permission for use forms. Phone orders are not accepted. ... Reproduction Price List SC-03 ReproductionPriceList.pdf - PDF document, 198 kB (202,819 bytes) ...
CSAPOER, sociology, UKOER, medical sociology, sociology of human reproduction, human reproduction Disciplines:. * Social ... Sociology of Human Reproduction This module examines the social and cultural relations of human reproduction. It outlines the ... It introduces a range of feminist theories on human reproduction and draws on empirical studies to explain and explore ... This module examines the social and cultural relations of human reproduction. It outlines the ways in which ideals about ...
  • 0005] The special reproduction is high-speed reproduction or low-speed reproduction such as rapid traverse (FF), rapid return (REW), rapid traverse reproduction (CUE), rapid return reproduction (REV), slow reproduction (SLOW), and frame skip (SKIP). (
  • Plant Reproduction (formerly known as Sexual Plant Reproduction ) is a journal devoted to publishing high-quality research in the field of reproductive processes in plants. (
  • The primary efforts of the Reproduction Research Unit are directed toward improving the reproductive efficiency of beef cattle, sheep, and swine. (
  • Sexual reproduction is a form of reproduction where two morphologically distinct types of specialized reproductive cells called gametes fuse together, involving a female's large ovum (or egg) and a male's smaller sperm. (
  • Moreover, when reproduction ceases, guppies from high-predation localities are far older, on average, than guppies from low-predation localities, indicating that high-predation guppies enjoy a long "reproductive period" the time between first and last reproduction. (
  • The reproduction of organisms by the union of male and female reproductive cells (gametes) is called sexual reproduction . (
  • Reproduction in which offspring are produced by a single parent, without the union of reproductive cells, is called asexual reproduction . (
  • Health problems linked to reproduction could increase the risk of hypertension, while hypertension or its drug treatment may have an impact on reproductive risk conditions, e.g., preeclampsia and erectile dysfunction. (
  • Unlike the sexually reproducing female population, both their somatic and reproductive eggs contain 50 chromosomes, assuring their clonal reproduction. (
  • This book blends feminist theory and philosophical expertise to provide a coherent analysis of a range of moral questions and social policy issues pertaining to human reproduction and the new reproductive technologies. (
  • In so doing, she develops a feminist approach to answering questions about reproductive rights and freedoms, the value of a genetic link between mother and their offspring, the commodification of reproduction, and the effects of reproductive technologies on women and children. (
  • In this volume, chapters focus on reproduction and sexuality among groups of fishes defined by habitat, taxon, and the reproductive processes that are critical for reproductive success. (
  • The journal's scope includes the study of reproductive physiology and endocrinology, reproductive cycles, natural and artificial control of reproduction, preservation and use of gametes and embryos, pregnancy and parturition, infertility and sterility, diagnostic and therapeutic techniques. (
  • Vegetative reproduction (also known as vegetative propagation , vegetative multiplication or vegetative cloning ) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment of the parent plant or grows from a specialized reproductive structure. (
  • Our reproductive capabilities are changing in exciting ways, altering our fundamental understanding of fertility, reproduction, and even parenthood. (
  • In this episode of Mind Over Chatter, we ask our guests what the consequences of novel reproductive technologies are likely to be, and how they will impact the future of human reproduction. (
  • This volume contains a selection of cases on assisted reproduction that will inform and challenge reproductive medicine practitioners at all stages in their careers. (
  • In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. (
  • Despite the obvious efficiencies of many forms of asexual reproduction, sexual reproduction abounds. (
  • The evolution of multicellular organisms has apparently passed through repeated losses and restorations of various forms of asexual reproduction [ 3 ]. (
  • Many forms of asexual reproduction, for example budding or fragmentation, produce an exact replica of the parent. (
  • Generally, parthenogenesis is considered a form of asexual reproduction because it does not involve fusion of gametes of opposite sexes, nor any exchange of genetic material from two different sources (Mayr 2001) however, some authorities (McGraw-Hill 2004) classify parthenogenesis as sexual reproduction on the basis that it involves gametes or does not produce an offspring genetically identical to the parent (such as a female domestic turkey producing male offspring). (
  • Since sexual reproduction is often more narrowly defined as the fusion of gametes (fertilization), spore formation in plant sporophytes and algae might be considered a form of asexual reproduction (agamogenesis) despite being the result of meiosis and undergoing a reduction in ploidy. (
  • A type of asexual reproduction in plants involving production of a new plant from the vegetative structures - stem, leaf, or root - of the parent plant. (
  • Vegetative propagation is a type of asexual reproduction found in plants where new individuals are formed without the production of seeds or spores and thus without syngamy or meiosis. (
  • Meristem tissue makes the process of asexual reproduction possible. (
  • Internal budding is a process of asexual reproduction, favoured by parasites such as Toxoplasma gondii. (
  • 0006] A user operates the special reproduction if search is conducted during, for example, reproduction. (
  • Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. (
  • The researchers now demonstrate that the success of the two reproduction methods could not be more different: "Mildew fungi detected on afflicted host plants have only successfully reproduced sexually every few centuries, primarily reproducing asexually instead," explains Wicker. (
  • Asexual reproduction as a success model seems to be characteristic of many parasitic fungi, including those that afflict humans, such as athlete's foot. (
  • Many plants and fungi reproduce asexually as well, and asexual reproduction has been cited in some animals, including bdelloid rotifers , which only are known to reproduce asexually, and various animals that exhibit parthenogenesis under certain conditions. (
  • Many protists and fungi alternate between sexual and asexual reproduction. (
  • For vegetative reproduction of animals and fungi, see Budding . (
  • This method of reproduction is found for example in conidial fungi and the red algae Polysiphonia, and involves sporogenesis without meiosis. (
  • Many plants also use a form of asexual reproduction called vegetative reproduction to duplicate themselves. (
  • Spider plants are excellent examples of plants that use vegetative reproduction. (
  • Whether it is a plant or an animal, or whether reproduction occurs by binary fission, budding, or vegetative reproduction, all reproduction that is asexual involves one parent passing on a duplicate of all of its genes to its offspring. (
  • Vegetative reproduction from a stem cutting less than a week old. (
  • While numerous plants reproduce by vegetative reproduction, they rarely exclusively use that method to reproduce. (
  • Although it has numerous advantages, vegetative reproduction is not evolutionary advantageous: it does not allow for genetic diversity and could lead plants to accumulate deleterious mutations. (
  • [3] Vegetative reproduction is, however, very useful as plants avoid the cost of sexual reproduction. (
  • Plants will resort to vegetative propagation when it allows individuals to produce more offspring per unit of resource than reproduction through seed production. (
  • Examples of vegetative reproduction include the formation of miniaturized plants called plantlets on specialized leaves, for example in kalanchoe (Bryophyllum daigremontianum) and many produce new plants from rhizomes or stolon (for example in strawberry). (
  • The known methods of reproduction are broadly grouped into two main types: sexual and asexual. (
  • For example, many plants alternate between sexual and asexual reproduction (see Alternation of generations), and the freshwater crustacean Daphnia reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to sexual reproduction as the intensity of competition and predation increases. (
  • Another great advantage is that even if there remains only a single individual, organisms capable of asexual reproduction can continue their species without a mate. (
  • In asexual reproduction, an individual can reproduce without involvement with another individual of that species. (
  • The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. (
  • An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. (
  • The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. (
  • The variety of manifestations of this phenomenon is even greater because asexual reproduction in different species has different biological functions, such as population growth, regulation of body size, colonization of new sites, and survival under adverse conditions. (
  • Right whales use social calls to mediate vital interactions, including mating, so a reduction in time or space for acoustic communication could have drastic implications for the species' survival and reproduction . (
  • and endangered species including zoo animals, but excluding laboratory animals unless the study reveals new information that impacts our basic understanding of the biology or manipulation of reproduction applicable to the animals listed above. (
  • Plant Propagation is the process of plant reproduction of a species or cultivar, and it can be sexual or asexual. (
  • Canine reproduction is the process of sexual reproduction in domestic dogs , wolves , coyotes and other canine species. (
  • Sexual reproduction is characterized by processes that pass a combination of genetic material to offspring , resulting in increased genetic diversity . (
  • Studies in model organisms where mechanisms of reproduction can be supported by genetic or biochemical evidence are strongly encouraged. (
  • It is a form of reproduction that does not involve the union of gametes (male and female sex cells), and therefore results in an offspring with the same genetic blueprint as the parent. (
  • With asexual reproduction, there is no opportunity for genetic variety. (
  • During asexual reproduction, the chromosomes divide by mitosis, which results in the exact duplication of the genetic material into the nuclei of the two daughter cells. (
  • Here we introduce an approach to engineer a genetic barrier to sexual reproduction between otherwise compatible populations. (
  • Asexual reproduction is a form of reproduction in which an organism creates a genetically-similar or identical copy of itself without a contribution of genetic material from another individual. (
  • Current hypotheses suggest that, while asexual reproduction may have short term benefits when rapid population growth is important or in stable environments, sexual reproduction offers a net advantage by allowing more rapid generation of genetic diversity, allowing adaptation to changing environments. (
  • The lack of genetic recombination results in fewer genetic alternatives than with sexual reproduction. (
  • While all prokaryotes reproduce without the formation and fusion of gametes, mechanisms for lateral gene transfer such as conjugation, transformation and transduction can be likened to sexual reproduction in the sense of genetic recombination in meiosis. (
  • Asexual reproduction is the production of new cells by simple division of the parent cell into two daughter cells (called binary fission). (
  • New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. (
  • The fission (splitting) of bacterial cells is a form of asexual reproduction. (
  • Bacterial conjugation , the transfer of DNA between two bacteria , is often mistakenly confused with sexual reproduction, because the mechanics are similar. (
  • Asexual reproduction is the primary form of reproduction for single-celled organisms such the archaea , bacteria , and protists . (
  • Kim Campbell Thornton Andrews Mcmeel, Star Tribune , "Letting your dog off leash can unleash a host of problems," 16 Oct. 2020 Because of their speedy reproduction patterns and semitransparency, zebrafish-and those vessels-are easy to study in the lab. (
  • Oliver Whang, National Geographic , "See the stunning world invisible to the naked eye," 13 Oct. 2020 Annual vines have to go through the growth/ reproduction cycle in just one year, so grow faster. (
  • Rasha Aridi, Smithsonian Magazine , "Blue Whales Sing All Day When They Migrate and All Night When They Don't," 8 Oct. 2020 Of the 51 examples, 44 had seen the virus's reproduction slow while social limits were in place. (
  • John Timmer, Ars Technica , "US states stopped their pandemic social restrictions too soon," 8 Oct. 2020 The reproduction is expected to return to Italy once the expo is over, but its fate, for now, is unknown. (
  • Elisabetta Povoledo, New York Times , "A High-Tech Twin for a Renaissance Masterpiece," 1 Oct. 2020 On Thursday, Los Angeles Mayor Eric Garcetti said the local viral reproduction rate - a measure of how much transmission is happening in the community - had climbed over 1, which meant the outbreak was starting to grow again. (
  • Sexual reproduction involves the fusion of two gamete cells (the sperm and ova) which each have half the normal number of chromosomes, a result of reduction division known as meiosis. (
  • C'est un mode de reproduction qui permet d'obtenir des individus toujours uniques grâce au brassage du patrimoine génétique (donc de l'ADN contenu dans les cellules en particulier sous forme de chromosomes). (
  • Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (such as a sperm or egg cell) with a single set of chromosomes (haploid) combines with another to produce an organism composed of cells with two sets of chromosomes (diploid). (
  • The study uncovered how female clones double their chromosomes twice to assure clonal reproduction. (
  • In asexual reproduction, an individual can reproduce without involvement with another individual, there is no fusion of gametes , and the new organism produced inherits all of its chromosomes from one parent and thus is a genetically-similar or identical copy of the parent. (
  • Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. (
  • 2. The video reproduction apparatus according to claim 1, wherein the reproduction section reads out, as the reproduction information, a file name of a file that was being reproduced and a frame number of a separate section that was being reproduced from the reproduction information storage section and acquires offset information based on the file name and frame number to determine the reproduction resuming position on the video information. (
  • 3. The video reproduction apparatus according to claim 2, wherein the reproduction section rounds down the offset information to acquire the top position of the video information frame and determines the acquired top position as the reproduction resuming position. (
  • 5. The video reproduction apparatus according to claim 4, wherein there is available user set information related to automatic restoration, which indicates whether the automatic restoration is performed or not, as the reproduction information, and when the automatic restoration is specified in the user set information, the reproduction section performs resume reproduction. (
  • 6. The video reproduction apparatus according to claim 1, wherein there is available user set information related to automatic restoration, which indicates whether the automatic restoration is performed or not, as the reproduction information, and when the automatic restoration is not specified in the user set information, the reproduction section resumes reproduction under the control of an externally connected reproduction operation section. (
  • 3. The reproduction apparatus according to claim 1 or 2 , wherein the storage means deletes the stored reproduction position when the special reproduction is executed subsequently. (
  • Cell reproduction usually involves division of a cell into two identical parts by means of mitosis or into four different parts by meiosis. (
  • Sexual reproduction involves the production of new cells by the fusion of sex cells (sperm and ova) to produce a genetically different cell. (
  • A more stringent definition is agamogenesis , which refers to reproduction without the fusion of gametes . (
  • Demographers, statisticians, and other researchers have an important new resource to understand the patterns of fertility, population growth, and change in the United States with the publication of "Reproduction Rates for 1990-2002 and Intrinsic Rates for 2000-2001: United States. (
  • The report includes rates of reproduction (total fertility rates, gross reproduction rates, and net reproduction rates), the intrinsic rate of natural increase, intrinsic birth rate, and intrinsic death rate. (
  • Among the race and Hispanic subgroups, the total fertility and gross reproduction rates were lower for all groups except Cuban and white women. (
  • Animal Reproduction Science publishes original research and timely reviews on topics relating to reproduction and fertility in animals . (
  • Historical demographer, Dr Alice Reid, who researches fertility, mortality and health in the late nineteenth and early twentieth centuries, tells us how reproduction has changed over the last 200 years and how it has been influenced by improvements in gender equality, as well as discussing the likely demographic impact of assisted reproduction. (
  • Asexual reproduction occurs when a new organism is produced from just one parent. (
  • The simplest form of asexual reproduction is when a single-celled organism like a bacterium splits into two. (
  • each individual organism exists as the result of reproduction. (
  • Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. (
  • Because asexual reproduction does not require the formation of gametes (often in separate individuals) and bringing them together for fertilization, nor involvement of another organism, it occurs much faster than sexual reproduction and requires less energy. (
  • Since 1998, VINTAGE PATTERN LENDING LIBRARY has been the 'go to' source for vintage sewing pattern reproductions. (
  • She is author of "Thinking Like a Woman: Personal Life and Political Ideas "(2001), "A Feminist I: Reflections from Academia "(1998), and "Human Reproduction: Principles, Practices, Policies "(1993), among other books. (
  • The achievement of such a difficult and complex feat (that is, asexually reproducing a mammal from a single cell taken from an adult rather than an embryo) raises the possibilities of asexual human reproduction. (
  • Where donor gametes are provided by a donor, the donor will be a biological parent of the resulting child, but in third party reproduction, he or she will not be the caring parent. (
  • A donor treatment is where gametes, i.e. sperm, ova or embryos are provided, or 'donated' by a third party for the purpose of third-party reproduction. (
  • Sexual reproduction is the union of male and female gametes to form a fertilized egg, or zygote . (
  • Reproduction takes many forms in sharks and rays, with the three main methods being oviparity, viviparity and ovoviviparity - although there are still variations within each. (
  • Likewise, processes of schooling in modern societies are among the main mechanisms of cultural reproduction, and do not operate solely through what is taught in courses of formal instruction. (
  • In regards to cultural reproduction, one of the main concepts of Bourdieu was introduced in Cultural Reproduction and Social Reproduction (1970), written with Jean-Claude Passeron, in which the writers primarily focus on the structural reproduction of disadvantages and inequalities that are caused by cultural reproduction. (
  • Human reproduction is any form of sexual reproduction resulting in human fertilization , typically involving sexual intercourse between a man and a woman. (
  • Human reproduction normally begins with copulation, followed by nine months of pregnancy before childbirth, though it may be achieved through artificial insemination . (
  • Human reproduction naturally takes place as internal fertilization by sexual intercourse. (
  • Third-party reproduction or donor-assisted reproduction is any human reproduction in which DNA or gestation is provided by a third party or donor other than the one or two parents who will raise the resulting child . (
  • This module examines the social and cultural relations of human reproduction. (
  • It introduces a range of feminist theories on human reproduction and draws on empirical studies to explain and explore theoretical issues. (
  • It shows the interrelationship between social structures and controls over human reproduction, and how studying the way that society understands human reproduction helps to understand these wider social structures. (
  • You just viewed Sociology of Human Reproduction . (
  • The intention is to have a comprehensive exposure to the whole setup of human assisted reproduction, which include lab set-up, clinical management and laboratory skills. (
  • Many books and materials give basic facts about male and female anatomy and the physical aspects of human reproduction. (
  • Alternatively, sexual reproduction may allow for the "ratcheting" of evolutionary speed as one clade competes with another for a limited resource. (
  • From the nineteenth century, it has been recognized that, since there is no obvious advantage to the individuals involved, the advantages of sexual reproduction must be evolutionary. (
  • And this is precisely where the advantage of sexual reproduction lies and why the usually unsuccessful sexual reproduction cycle is still worthwhile for the mildew fungus: Wheat and mildew are embroiled in a permanent evolutionary arms race. (
  • A lack of sexual reproduction is relatively rare among multicellular organisms, which exhibit the characteristics of being male or female. (
  • The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent. (
  • This course is one of the best courses available world-wide which focus on the field of assisted reproduction with hands-on training throughout the course duration. (
  • This means that the offspring produced by asexual reproduction are genetically identical copies, or clones, of the parent. (
  • printed 1000 copies of the lithograph facsimile suggests a close reproduction often of graphic matter that may differ in scale. (
  • This Music Mass Reproduction License allows unlimited copies of downloaded or physical End Products (unlike our Music Standard License which has a limit on these). (
  • This series of volumes represents a comprehensive and integrated treatment of reproduction in vertebrates from fishes of all sorts through mammals. (
  • Reproduction by fragmentation or regeneration is related to budding. (
  • 0004] A reproduction apparatus that reproduces data such as a video or a music recorded on a randomly accessible recording medium such as a DVD or a hard disk can perform not only normal reproduction but also special reproduction for reproducing data at a speed different from a speed for the normal reproduction. (
  • Scientists are still unsure why whales sing, but this study suggests that information about behavior, reproduction , and migration could be embedded in the whales' songs, Oestreich tells Science News. (
  • These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reproduction. (
  • News about Repro Medical System Inc., including commentary and archival articles published in The New York Times. (
  • Asexual reproduction is not, however, limited to single-celled organisms. (
  • Biological processes involving lateral gene transfer sometimes are likened to sexual reproduction (Narra and Ochman 2006). (
  • When asexual reproduction occurs, the new individuals are called clones, because they are exact duplicates of their parent cells. (
  • A major question is why sexual reproduction persists when parthenogenesis appears in some ways to be a superior form of reproduction . (
  • In asexual reproduction, eggs develop without fertilization, a process called parthenogenesis. (
  • However, both events (spore formation and fertilization) are necessary to complete sexual reproduction in the plant life cycle. (
  • Reproduction is the process by which new organisms are produced from existing ones. (
  • A new study conducted by researchers at Northwestern University examined the costs of reproduction in roundworms, otherwise known as C. elegans. (
  • Dictionary , Merriam-Webster, (
  • فبراير 2016) التكاثر الجنسي (بالإنجليزية: Sexual reproduction) هو عملية تكاثر تضمن التنوع الوراثي للنسل يتم فيها اتحاد مشيج ذكري (حيوان منوي عند الثدييات) مع مشيج أنثوي (بويضة) بهدف تشكيل لاقحة (بويضة ملقحة) تنمو لتعطي فرداً جديداً. (
  • Carlson, A.R. (1971) Effects of long-term exposure to carbaryl (Sevin) on survival, growth, and reproduction of the fathead minnow ( Pimephales promelas ). (
  • Craig, G.R. and Bakshi, W.F. (1977) The effects of depressed pH on flagfish reproduction, growth and survival. (
  • Since there is no fusion of two different cells, the daughter cells produced by asexual reproduction are genetically identical to the parent cell. (
  • A consequence of asexual reproduction, which may have both benefits and costs, is that offspring are typically genetically similar to their parent, with as broad a range as that individual receives from one parent. (
  • If you know the author of Plant Reproduction - They'll Make More , please help us out by filling out the form below and clicking Send. (
  • Hawkweed ( Hieracium ), dandelion ( Taraxacum ), some citrus ( Citrus ) and many grasses such as Kentucky bluegrass ( Poa pratensis ) all use this form of asexual reproduction. (
  • Once you have selected the materials you wish to be reproduced, please complete the textual or audiovisual reproduction request form, and send it to the Research Room staff . (
  • Articles are selected based on significance for the field of plant reproduction, spanning from the induction of flowering to fruit development. (
  • This is an informative website that talks about plant reproduction. (
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  • Cultural reproduction, a concept first developed by French sociologist and cultural theorist Pierre Bourdieu, is the mechanisms by which existing cultural forms, values, practices, and shared understandings (i.e., norms) are transmitted from generation to generation, thereby sustaining the continuity of cultural experience across time. (
  • Bourdieu's sociological work was dominated by an analysis of the mechanisms of reproduction of social hierarchies. (