Zygote: The fertilized OVUM resulting from the fusion of a male and a female gamete.Chlamydomonas: A genus GREEN ALGAE in the order VOLVOCIDA. It consists of solitary biflagellated organisms common in fresh water and damp soil.Chlamydomonas reinhardtii: A species of GREEN ALGAE. Delicate, hairlike appendages arise from the flagellar surface in these organisms.Zygote Intrafallopian Transfer: 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).Algal Proteins: Proteins found in any species of algae.Diploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.Flagella: A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Blastocyst: A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.Chloroplasts: Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.Haploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.Phaeophyta: A division of predominantly marine EUKARYOTA, commonly known as brown algae, having CHROMATOPHORES containing carotenoid PIGMENTS, BIOLOGICAL. ALGINATES and phlorotannins occur widely in all major orders. They are considered the most highly evolved algae because of their well-developed multicellular organization and structural complexity.Cleavage Stage, Ovum: The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.Fertilization in Vitro: An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.Embryonic Development: Morphological and physiological development of EMBRYOS.RNA, Algal: Ribonucleic acid in algae having regulatory and catalytic roles as well as involvement in protein synthesis.Oocytes: 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).Chlorophyta: A phylum of photosynthetic EUKARYOTA bearing double membrane-bound plastids containing chlorophyll a and b. They comprise the classical green algae, and represent over 7000 species that live in a variety of primarily aquatic habitats. Only about ten percent are marine species, most live in freshwater.Embryo Culture Techniques: The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.Triploidy: 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.Ploidies: The degree of replication of the chromosome set in the karyotype.Embryo Transfer: 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.Morula: An early embryo that is a compact mass of about 16 BLASTOMERES. It resembles a cluster of mulberries with two types of cells, outer cells and inner cells. Morula is the stage before BLASTULA in non-mammalian animals or a BLASTOCYST in mammals.Embryonic and Fetal Development: Morphological and physiological development of EMBRYOS or FETUSES.Molecular Sequence Data: 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.Mutation: 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.Dyneins: A family of multisubunit cytoskeletal motor proteins that use the energy of ATP hydrolysis to power a variety of cellular functions. Dyneins fall into two major classes based upon structural and functional criteria.Axoneme: A bundle of MICROTUBULES and MICROTUBULE-ASSOCIATED PROTEINS forming the core of each CILIUM or FLAGELLUM. In most eukaryotic cilia or flagella, an axoneme shaft has 20 microtubules arranged in nine doublets and two singlets.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Cytochromes f: Cytochromes f are found as components of the CYTOCHROME B6F COMPLEX. They play important role in the transfer of electrons from PHOTOSYSTEM I to PHOTOSYSTEM II.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Spermatozoa: 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.DNA, Algal: Deoxyribonucleic acid that makes up the genetic material of algae.Sperm Injections, Intracytoplasmic: 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).Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Embryo, Mammalian: The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Germ Cells, Plant: The reproductive cells of plants.Protozoan Proteins: Proteins found in any species of protozoan.Crosses, Genetic: 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.Microinjections: The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.Parthenogenesis: 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.Amino Acid Sequence: 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.Cytochrome b6f Complex: A protein complex that includes CYTOCHROME B6 and CYTOCHROME F. It is found in the THYLAKOID MEMBRANE and plays an important role in process of PHOTOSYNTHESIS by transferring electrons from PLASTOQUINONE to PLASTOCYANIN or CYTOCHROME C6. The transfer of electrons is coupled to the transport of PROTONS across the membrane.Cryopreservation: 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.Blastomeres: Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.Nuclear Transfer Techniques: Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.Photosystem II Protein Complex: A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.Chlorophyll: Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.Embryo Implantation: Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Genes, Protozoan: The functional hereditary units of protozoa.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Meiosis: 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.Microtubules: Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.Aneuploidy: The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Ectogenesis: Embryonic and fetal development that takes place in an artificial environment in vitro.Ovum: A mature haploid female germ cell extruded from the OVARY at OVULATION.Photosystem I Protein Complex: A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.Fallopian Tubes: A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.Photosynthetic Reaction Center Complex Proteins: Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.Karyotyping: Mapping of the KARYOTYPE of a cell.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Cytoplasm: The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Tetraploidy: The presence of four sets of chromosomes. It is associated with ABNORMALITIES, MULTIPLE; and MISCARRAGES.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Culture Techniques: Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.Plastocyanin: A copper-containing plant protein that is a fundamental link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.Transformation, Genetic: Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.Cell Polarity: Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.Eukaryota: One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.Thylakoids: Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.Micromanipulation: The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.Alstroemeria: A plant genus of the family LILIACEAE. Members contain allergens, tuliposide A and tulipalin A.Fetal Viability: The potential of the FETUS to survive outside the UTERUS after birth, natural or induced. Fetal viability depends largely on the FETAL ORGAN MATURITY, and environmental conditions.Animals, Inbred Strains: Animals produced by the mating of progeny over multiple generations. The resultant strain of animals is virtually identical genotypically. Highly inbred animal lines allow the study of certain traits in a relatively pure form. (Segen, Dictionary of Modern Medicine, 1992)Superovulation: Occurrence or induction of release of more ova than are normally released at the same time in a given species. The term applies to both animals and humans.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Chromosomes: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)5-Methylcytosine: A methylated nucleotide base found in eukaryotic DNA. In ANIMALS, the DNA METHYLATION of CYTOSINE to form 5-methylcytosine is found primarily in the palindromic sequence CpG. In PLANTS, the methylated sequence is CpNpGp, where N can be any base.Mitosis: A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.Genes, Plant: The functional hereditary units of PLANTS.Light-Harvesting Protein Complexes: Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS and are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.Metaphase: The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.Seeds: 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.
... which can fuse to form a diploid zygote. The zygote is not flagellated, and it serves as a dormant form of the species in the ... The dynamic behaviour of mitochondria in living zygotes during maturation and meiosis in Chlamydomonas reinhardtii. Eur. J. ... Chlamydomonas species are widely distributed worldwide in soil and fresh water. Chlamydomonas reinhardtii is an especially well ... Since Chlamydomonas species are normally haploid, the effects of mutations are seen immediately without further crosses. In ...
This type occurs for example in algae such as some but not all species of Chlamydomonas. In another type, neither of the ... Karyogamy (fusion of nuclei) then eventually occurs in sporangia, and leads to the formation of diploid cells (zygotes) that ... forming a zygote. In ciliates, cell fission may follow self-fertilization (autogamy), or it may follow conjugation (exchange of ... In several lineages (plants, animals), this form of reproduction independently evolved to anisogamous species with gametes of ...
... the zygote divides mitotically to produce a multicellular diploid individual or a group of more unicellular diploid cells. ... In the whole cycle, zygotes are the only diploid cell; mitosis occurs only in the haploid phase. The individuals or cells as a ... In some organisms, different "generations" of the species succeed each other during the life cycle. For plants and many algae, ... Haplonts are: In archaeplastidans: some green algae (e.g., Chlamydomonas, Zygnema, Chara) In stramenopiles: some golden algae ...
The human zygote has been genetically edited in experiments designed to cure inherited diseases. A Chlamydomonas zygote that ... This cell may then enter meiosis or mitosis depending on the life cycle of the species. In plants, the zygote may be polyploid ... The result of karyogamy is the formation of a diploid cell called zygote or zygospore. ... generally are rare since normally cpDNA is inherited uniparental from the mt+ mating type parent.These rare biparental zygotes ...
Pregnancy has been traditionally defined as the period during which developing embryos are incubated in the body after egg-sperm union. Although the term often refers to placental mammals, it has also been used in the titles of many international, peer-reviewed, scientific articles on fish, e.g. Consistent with this definition, there are several modes of reproduction in fish, providing different amounts of parental care. In ovoviviparity, there is internal fertilization and the young are born live but there is no placental connection or significant trophic (feeding) interaction; the mother's body maintains gas exchange but the unborn young are nourished by egg yolk. There are two types of viviparity in fish. In histotrophic viviparity, the zygotes develop in the female's oviducts, but she provides no direct nutrition; the embryos survive by eating her eggs or their unborn siblings. In hemotrophic viviparity, the ...
... or Bilaminar disc refers to the epiblast and the hypoblast, evolved from the embryoblast. These two layers are sandwiched between two balloons: the primitive yolk sac and the amniotic cavity. The inner cell mass, the embryoblast, begins to transform into two distinct epithelial layers just before implantation occurs. The epiblast is the outer layer that consists of columnar cells.The inner layer is called the hypoblast, or primitive endoderm, which is composed of cuboidal cells. As the two layers become evident, a basement membrane presents itself between the layers. The final two layers of the embryoblast are known collectively as the bilaminar embryonic disc as well as the bilaminar blastocyst or bilaminar blastoderm. This bilaminar blastocyst also defines the primitive dorsal ventral axis. Blastocyst implantation will occur during the second week of fetal development in the endometrium of the uterus; the epiblast is dorsal and the hypoblast is ventral. The zygote ...
... is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo. Although embryogenesis occurs in both animal and plant development, this article addresses the common features among different animals, with some emphasis on the embryonic development of vertebrates and mammals. The egg cell is generally asymmetric, having an "animal pole" (future ectoderm and mesoderm) and a "vegetal pole" (future endoderm). It is covered with protective ...
The female reproductive system likewise contains two main divisions: the vagina and the Ovum. The ovum meets with sperm cell, a sperm may penetrate and merge with the egg, fertilizing it with the help of certain hydrolytic enzymes present in the acrosome. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then becomes implanted in the lining of the uterus, where it begins the processes of embryogenesis and morphogenesis. When the fetus is developed enough to survive outside of the uterus, the cervix dilates and contractions of the uterus propel it through the birth canal, which is the vagina. The ova, which are the female sex cells, are much larger than the spermatozoon and are normally formed within the ovaries of the female fetus before its birth. They are mostly fixed in location within the ovary until their transit to the uterus, and contain nutrients for the later zygote and embryo. Over a, ...
... is the process of development of the differences between males and females from an undifferentiated zygote. As male and female individuals develop from zygotes into fetuses, into infants, children, adolescents, and eventually into adults, sex and gender differences at many levels develop: genes, chromosomes, gonads, hormones, anatomy, and psyche. Sex differences range greatly and include physiologically differentiating. Sex-dichotomous differences are developments which are wholly characteristic of one sex only. Examples of sex-dichotomous differences include aspects of the sex-specific genital organs such as ovaries, a uterus or a phallic urethra. In contrast, sex-dimorphic differences are matters of degree (e.g., size of phallus). Some of these (e.g., stature, behaviors) are mainly statistical, with much overlap between male and female populations. Nevertheless, even the sex-dichotomous differences are not absolute in ...
Most species in this family infect the Malpigian tubes of beetles. The trophozoite is conical in shape. Two types of schizogony occur in this family. In the first type the schizonts divide into merozoites with small nuclei. These are known as mycetoids merozoites. These develop into trophozoites. In the second form and more common form, the schizonts divide into merozoites with large nuclei: these are known as gregarinoid merozoites and give rise to gametocytes. The merozoites are uninucleated, pyriform cells. These are released into the lumen of the tube and from there infect other cells of the tube. The gametocytes possesses only a single nucleus and are globular in shape. When mature, these become detached from the epithelium. Within the lumen, the gametocytes associate in pairs, fuse and form a zygote. The zygote subsequently becomes a single octozoic spore. ...
நிசாருதீன், நீங்கள் தந்த இணைப்பின் வழியாக http://dictionary.sarma.co.in மற்றும் http://www.tamildict.com ஆகிய தளங்களைப் பார்த்தேன். அவ்விடங்களில் zygote என்பதற்கு புணரிக்கலம், நுகம் ஆகிய சொற்களைத் தந்துள்ளார்கள். நன்றி. அ.கி. மூர்த்தியின் அறிவியல் அகராதியில் கருவணு என்று கொடுத்துள்ளார்கள். கருவணு என்பது வேறு அணுக்கரு என்பது வேறு என்பது தெளிவாகத்தானே இருக்கின்றது. தலைநாய் வேறு நாய்த்தலை வேறு அல்லவா. மேலும் ...
P. flava's early cleavage pattern is similar to that of S. kowalevskii. The first and second cleavages from the single cell zygote of P. flava are equal cleavages, are orthogonal to each other and both include the animal and vegetal poles of the embryo. The third cleavage is equal and equatorial so that the embryo has four blastomeres both in the vegetal and the animal pole. The fourth division occurs mainly in blastomeres in the animal pole, which divide transversally as well as equally to make eight blastomeres. The four vegetal blastomeres divide equatorially but unequally and they give rise to four big macromeres and four smaller micromeres. Once this fourth division has occurred, the embryo has reached a 16 cell stage. P. flava has a 16 cell embryo with four vegetal micromeres, eight animal mesomeres and 4 larger macromeres. Further divisions occur until P. flava finishes the blastula stage and goes on to gastrulation. The animal mesomeres of P. flava go on to give rise ...
In animals, the development of the zygote into an embryo proceeds through specific recognizable stages of blastula, gastrula, and organogenesis. The blastula stage typically features a fluid-filled cavity, the blastocoel, surrounded by a sphere or sheet of cells, also called blastomeres. In a placental mammal, an ovum is fertilized in a fallopian tube through which it travels into the uterus. An embryo is called a fetus at a more advanced stage of development and up until birth or hatching. In humans, this is from the eleventh week of gestation. However, animals which develop in eggs outside the mother's body, are usually referred to as embryos throughout development; e.g. one would refer to a chick embryo, not a "chick fetus," even at later stages.. During gastrulation the cells of the blastula undergo coordinated processes of cell division, invasion, and/or migration to form two (diploblastic) or three (triploblastic) tissue layers. In triploblastic organisms, the three ...
Systematically they fall within the division Charophyta/Streptophyta, in which the land plants (Embryophyta) emerged.[2]. Sexual reproduction in Zygnematales takes place through a process called conjugation.[3] Here filaments of opposite gender line up, and tubes form between corresponding cells. The male cells then become amoeboid and crawl across, or sometimes both cells crawl into the tube. The cells then meet and fuse to form a zygote, which later undergoes meiosis to produce new filaments. As in plants, only the female passes chloroplasts on to the offspring.[citation needed]. Other conjugating algae are the Mesotaeniaceae, sister of the Zygnematales, and spirotaenia, a basal green algae. Additionally, the Desmidiales appear to have emerged deep within the Zygnematales, and are also conjugating.[4]. ...
The radial spoke is known to play a role in the mechanical movement of the flagellum/cilium. For example, mutant organisms lacking properly functioning radial spokes have flagella and cilia that are immotile. Radial spokes also influence the cilium "waveform"; that is, the exact bending pattern the cilium repeats. How the radial spoke carries out this function is poorly understood. Radial spokes are believed to interact with both the central pair microtubules and the dynein arms, perhaps in a way that maintains the rhythmic activation of the dynein motors. For example, one of the radial spoke subunits, RSP3, is an anchor protein predicted to hold another protein called protein kinase A (PKA). PKA would theoretically then be able to activate/inactivate the adjacent dynein arms via its kinase activity. However, the identities and functions of the many radial spoke subunits are just beginning to be elucidated. ...
In 1933, Marjory Stephenson and her student Stickland reported that cell suspensions catalysed the reduction of methylene blue with H2. Six years later, Hans Gaffron observed that the green photosynthetic alga Chlamydomonas reinhardtii, would sometimes produce hydrogen.[17] In the late 1990s Anastasios Melis discovered that deprivation of sulfur induces the alga to switch from the production of oxygen (normal photosynthesis) to the production of hydrogen. He found that the enzyme responsible for this reaction is hydrogenase, but that the hydrogenase lost this function in the presence of oxygen. Melis also discovered that depleting the amount of sulfur available to the algae interrupted their internal oxygen flow, allowing the hydrogenase an environment in which it can react, causing the algae to produce hydrogen.[18] Chlamydomonas moewusii is also a promising strain for the production of hydrogen.[19][20] ...
Faragó, A. and Dénes, G. (1967). „Mechanism of arginine biosynthesis in Chlamydomonas reinhardti. II. Purification and properties of N-acetylglutamate 5-phosphotransferase, the allosteric enzyme of the pathway". Biochim. Biophys. Acta. 136: 6-18. PMID 6040410 ...
Diploid Zygotes withstand unfavorable conditions 6. (No Transcript) 7. Sexual differentiation in Chlamydomonas*Meiosis occurs ... Sex Determination - Even species where both mating types can reproduce pay a price for sex ... Jamie Lee Curtis. XY with AIS? ... diploid zygote nucleus *One sperm unites with the two endosperm nuclei triploid endosperm nucleus ... Model organisms (Chlamydomonas (Green algae), Zea Mays (plant), C. elegans, Protenor (insect), Lygaeus turicus (insect), ...
Sexual reproduction is characterized by the formation of a zygospore (a dormant diploid zygote protected by a thick wall) that ... Most living species are grouped in classes that are coextensive with three of these lineages. Class Chlorophyceae. This group ... They have an alternation of generations and unlike in the other classes, meiosis occurs in the spores rather than the zygotes. ... The class includes unicellular organisms such as those in the genus Chlamydomonas with their two apical flagella and nonmotile ...
... which can fuse to form a diploid zygote. The zygote is not flagellated, and it serves as a dormant form of the species in the ... The dynamic behaviour of mitochondria in living zygotes during maturation and meiosis in Chlamydomonas reinhardtii. Eur. J. ... Chlamydomonas species are widely distributed worldwide in soil and fresh water. Chlamydomonas reinhardtii is an especially well ... Since Chlamydomonas species are normally haploid, the effects of mutations are seen immediately without further crosses. In ...
Upon fertilization Chlamydomonas reinhardtii zygotes undergo a program of differentiation into a diploid zygospore that is ... Reactive oxygen species (ROS) are produced by and have the potential to be damaging to all aerobic organisms. In photosynthetic ... accompanied by transcription of hundreds of zygote-specific genes. We identified a distinct sequence motif we term a zygotic ... The Chlamydomonas Genome Reveals the Evolution of Key Animal and Plant Functions journal, October 2007 * Merchant, S. S.; ...
One of the male gametes fuses with the egg cell to form a zygote (syngamy). The other male gamete fuses with the diploid ... Many algae such as Volvox, Spirogyra and some species of Chlamydomonas represent this pattern. ... An antherozoid fuses with the egg to produce the zygote. Zygotes do not undergo reduction division immediately. They produce a ... Following fertilization the zygote also divides by mitosis to produce a diploid sporophytic plant body. ...
The resultant diploid zygote then produces a few diploid carpospores, which are release into the water.. Carpospores produce ... The zygotes remain attached to the parental thallus, which stimulate the growth of a layer of cells that covers the zygotes.. ... Marine species have an alternation of isomorphic generations.. Most of the fresh water species do not have an alternation of ... Chlamydomonas is motile unicellular chlorophyte.. Two equal flagella.. One chloroplast with a red photosensitive eyespot, or ...
The resultant diploid zygote then produces a few diploid carpospores, which are release into the water.. Carpospores produce ... The zygotes remain attached to the parental thallus, which stimulate the growth of a layer of cells that covers the zygotes.. ... Marine species have an alternation of isomorphic generations.. Most of the fresh water species do not have an alternation of ... Chlamydomonas is motile unicellular chlorophyte.. Two equal flagella.. One chloroplast with a red photosensitive eyespot, or ...
The resultant diploid zygote then produces a few diploid carpospores, which are release into the water.. Carpospores produce ... In some, the haploid phase represents the individual; in others, it is the diploid phase.. In dibiontic species, both stages of ... The zygotes remain attached to the parental thallus, which stimulate the growth of a layer of cells that covers the zygotes.. ... Chlamydomonas is motile unicellular chlorophyte.. Two equal flagella.. One chloroplast with a red photosensitive eyespot, or ...
The resultant diploid zygote then produces a few diploid carpospores, which are release into the water.. Carpospores produce ... In some, the haploid phase represents the individual; in others, it is the diploid phase.. In dibiontic species, both stages of ... The zygotes remain attached to the parental thallus, which stimulate the growth of a layer of cells that covers the zygotes. ... Chlamydomonas is motile unicellular chlorophyte.. Two equal flagella.. One chloroplast with a red photosensitive eyespot, or ...
Upon fertilization Chlamydomonas reinhardtii zygotes undergo a program of differentiation into a diploid zygospore that is ... we show this galactose-mediated regulation of PGM1/2 supports vigorous growth on galactose in multiple yeast species, including ... accompanied by transcription of hundreds of zygote-specific genes. We identified a distinct sequence motif we term a zygotic ... Identification and characterization of a cis-regulatory element for zygotic gene expression in Chlamydomonas reinhardtii ...
... species Species-group of organisms that are able to produce viable offspring Phyla in plants are called divisions Dichotomous ... Classified species based on natural relationships ( behavior, structure and habitat) Systematics is a broader science that ... Believed species were fixed Linnaeus-Father of taxonomy. ... only the zygote is diploid. Zygotes undergo meiosis and become ... P. Chlorophyta - green algae Chlamydomonas, Volvox, some seaweeds, sea lettuce P. Chrysophyta - golden-brown algae -Ex: Diatoms ...
Throughout, changes were made in the species used as illustrative examples. Information on number of species in different taxa ... The discussion on the effects of mutations on diploid versus haploid bodies has been clarified. The difference between animal ... Distinctions between gamete and gametophyte, male and female gametophyte, zygote and embryo, and gymnosperms and angiosperms ... and Chlamydomonas genome. Changes in section headings more clearly describe section contents. Numerous figures were updated to ...
Type species. This is the type species (holotype) of the genus Chlamydomonas. ... Matagne, R.F. & Orbans, A. (1980). Somatic segregation in diploid Chlamydomonas reinhardtii. Journal of General Microbiology ... Van Winkle-Swift, K.P. (1977). Maturation of algal zygotes: alternative experimental approaches for Chlamydomonas reinhardtii ( ... A zygote-specific protein with hydroxyproline-rich glycoprotein domains and lectin-like domains involved in the assembly of the ...
Diploid zygotes differentiate into environmentally resistant, orange-pigmented, dormant zygospores that when germinated undergo ... Volvocine algae include isogamous species such as Chlamydomonas reinhardtii, with two equal-sized mating types, and oogamous ... Black arrowhead shows a normal-appearing developed zygote; white arrowhead shows an aborted zygote. (D) Hermaphrodite phenotype ... E) Mature zygote from Eve::VcMID-BH×Eve. (F) Sperm packet from wild-type AichiM. (G) Sperm packet from pseudo-male Eve::VcMID- ...
The individual zygotes or diploid cells were analyzed using nested PCR: first amplification, cytb_F1 + cytb_R2 primers; and ... In the related species Chlamydomonas monoica, two mutants have been obtained that alter uniparental inheritance. The mtl-1 ... 1978). Uniparental inheritance is promoted by delayed division of the zygote in Chlamydomonas. Nature 275: 749-751. ... bp31 mt+ gametes fuse normally to form zygotes, but the sexual development of the resulting diploid cell is arrested and ...
The two nuclei fuse in the dikaryon, producing the diploid zygote. (B) Flagellar adhesion initiates a signal cascade involving ... 2 B, lane 4). C-PKD2 did not recognize the 120-kD protein, suggesting that this species lacks the C terminus. The simplest ... and the number of the quadriflagellate zygotes and biflagellate cells were counted by phase-contrast microscopy (Martin and ... Function and dynamics of PKD2 in Chlamydomonas reinhardtii flagella. Kaiyao Huang, Dennis R. Diener, Aaron Mitchell, Gregory J. ...
d. Myxamoeba and swarm cells are initially haploid, but eventually fuse to form a diploid zygote e. Zygote feeds, grows and ... Multicellular seaweeds; some species have the largest linear dimensions known in the eucaryotic world 11. Simplest species have ... 2. Genus Chlamydomonas-Members of this genus are microscopic, rounded, with two flagella at anterior end; have single haploid ... 5. Zygotes can develop into spores (zygospores, ascospores, or basidiospores); spores are used for identification purposes and ...
1/3 of number of wild-type zygotes with overnight incubation, while a fourth (#1) mated normally, and produced normal zygote ... Expression of GSP1 occurs in mid-1 and wild-type plus gametes but not in wild-type minus gametes nor in mt+/mt− diploids (K ... 2002). This is a totally different species from Mtd1, which is predicted to be a transmembrane protein (Ferris et al. 2002). ... 2002). This protein is not essential to Chlamydomonas: MID-transformed mt+ gametes are able to form viable zygotes with wild- ...
Chlamydomonas reinhardtii). FUS1. NA. JGI:Cre06. g252750.t1.1; NCBI:U49864. Genetic reagent (Chlamydomonas reinhardtii, mt+). ... H) Representative DIC images showing that wt- x wt+ gametes form zygotes; wt- x fus1+ fail to form pairs; and hap2-, fh1-, fh2, ... A defining event of sex is fusion of the plasma membranes of two haploid gametes to generate a new diploid cell, yet we still ... Sequence and structure-based alignments of HAP2 from diverse species and Dengue 2 class II viral fusogen.. HAP2 sequences were ...
Pollen tube enters into the embryosac and one male gamete fuses with egg and diploid zygote is formed. It is called syngamy. ... Fusion of two gametes dissimilar in size, as in some species of chlamydomonas is termed as anisogamous. Fusion between one ... An antherozoid fuses with the egg to produce the zygote. Zygotes do not undergo reduction division immediately. They produce a ... After fertilisation, zygote also divides by mitosis to produce a diploid sporophytic plant body. ...
An embryo may develop, for example, from a 2n nutritive cell or other diploid cell of an ovule, instead of from a zygote. After ... For example, some wildflower books arrange together all white-flowered species or all yellow-flowered species. There is nothing ... A small, actively moving little alga, Chlamydomonas Fig. 18.3 is a common inhabitant of quiet freshwater pools. It has an ... structures consist of a single cell or with sterile cells surrounding the one-celled reproductive structures zygotes not ...
Cross-species EST alignments reveal novel and conserved alternative splicing events in legumes Author(s): Wang Bing-Bing , ... Diploid parthenogenesis and early embryo development in Norway spruce cell suspensions Author(s): Durzan Don , Santerre Anne ... Polarization of the endomembrane system is an early event in fucoid zygote development Author(s): Hadley Rhett , Hable Whitney ... Kinesin-5 motors are required for organization of spindle microtubules in Silvetia compressa zygotes Author(s): Peters Nick , ...
Matagne, R.F. & Orbans, A. (1980). Somatic segregation in diploid Chlamydomonas reinhardtii. Journal of General Microbiology ... Van Winkle-Swift, K.P. (1977). Maturation of algal zygotes: alternative experimental approaches for Chlamydomonas reinhardtii ( ... A zygote-specific protein with hydroxyproline-rich glycoprotein domains and lectin-like domains involved in the assembly of the ... Szivák, I., Behra, R. & Sigg, L. (2009). Metal-induced reactive oxygen species production in Chlamydomonas reinhardtii ( ...
  • Through targeted mutations of predicted Gal4-binding sites in yeast genomes, we show this galactose-mediated regulation of PGM1/2 supports vigorous growth on galactose in multiple yeast species, including Saccharomyces uvarum and Lachancea kluyveri . (osti.gov)
  • Furthermore, the addition of galactose-inducible PGM1 alone is sufficient to improve the growth on galactose of multiple species that lack this regulation, including Saccharomyces cerevisiae. (osti.gov)
  • The strong association between regulation of PGM1/2 by Gal4 even enables remarkably accurate predictions of galactose growth phenotypes between closely related species. (osti.gov)
  • The fact that these diploids always mate as minus indicates that minus is dominant to plus ( H arris 1989 ), a phenomenon found to be controlled by the MID gene ( G alloway and G oodenough 1985 ). (genetics.org)
  • Male and female sexes have evolved repeatedly in eukaryotes but the origins of dimorphic sexes and their relationship to mating types in unicellular species are not understood. (nih.gov)