Gymnosperms: Gymnosperms are a group of vascular plants whose seeds are not enclosed by a ripened ovary (fruit), in contrast to ANGIOSPERMS whose seeds are surrounded by an ovary wall. The seeds of many gymnosperms (literally, "naked seed") are borne in cones and are not visible. Taxonomists now recognize four distinct divisions of extant gymnospermous plants (CONIFEROPHYTA; CYCADOPHYTA; GINKGOPHYTA; and GNETOPHYTA).Angiosperms: 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.Picea: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen, pyramidal trees with whorled branches and thin, scaly bark. Each of the linear, spirally arranged leaves is jointed near the stem on a separate woody base.Cycas: A plant genus of the family Cycadaceae, order Cycadales, class Cycadopsida, division CYCADOPHYTA of palm-like trees. It is a source of CYCASIN, the beta-D-glucoside of methylazoxymethanol.Coniferophyta: A plant division of GYMNOSPERMS consisting of cone-bearing trees and shrubs.Pinus: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen trees mainly in temperate climates.Taxus: Genus of coniferous yew trees or shrubs, several species of which have medicinal uses. Notable is the Pacific yew, Taxus brevifolia, which is used to make the anti-neoplastic drug taxol (PACLITAXEL).Pinaceae: A plant family of the order Pinales, class Pinopsida, division Coniferophyta, known for the various conifers.Ginkgo biloba: The only specie of the genus Ginkgo, family Ginkgoacea. It is the source of extracts of medicinal interest, especially Egb 761. Ginkgo may refer to the genus or species.Pinus taeda: A plant species of the genus PINUS which is the subject of genetic study.Cycadophyta: A division of GYMNOSPERMS which look like palm trees (ARECACEAE) but are more closely related to PINUS. They have large cones and large pinnate leaves and are sometimes called cycads, a term which may also refer more narrowly to cycadales or CYCAS.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Zamiaceae: A plant family of the order Cycadales, class Cycadopsida, division CYCADOPHYTA.Ephedra: A plant genus of the family Ephedraceae, order Ephedrales, class Gnetopsida, division Gnetophyta.Ferns: Seedless nonflowering plants of the class Filicinae. They reproduce by spores that appear as dots on the underside of feathery fronds. In earlier classifications the Pteridophyta included the club mosses, horsetails, ferns, and various fossil groups. In more recent classifications, pteridophytes and spermatophytes (seed-bearing plants) are classified in the Subkingdom Tracheobionta (also known as Tracheophyta).Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Selaginellaceae: A plant family of the order Selaginellales, class Lycopodiopsida, division Lycopodiophyta, subkingdom Tracheobionta. Members contain bilobetin. The rarely used common name of resurrection plant is mainly used with CRATEROSTIGMA.Genes, Plant: The functional hereditary units of PLANTS.Ovule: The element in plants that contains the female GAMETOPHYTES.Ocotea: A plant genus in the LAURACEAE family. The common name of stinkwood is also used for Zieria (RUTACEAE).Cambium: A layer of living cells between the bark and hardwood that each year produces additional wood and bark cells, forming concentric growth rings.Pseudotsuga: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are coniferous evergreen trees with long, flat, spirally arranged needles that grow directly from the branch.Lignin: The most abundant natural aromatic organic polymer found in all vascular plants. Lignin together with cellulose and hemicellulose are the major cell wall components of the fibers of all wood and grass species. Lignin is composed of coniferyl, p-coumaryl, and sinapyl alcohols in varying ratios in different plant species. (From Merck Index, 11th ed)Cupressaceae: A plant family of the order Pinales, class Pinopsida, division Coniferophyta (conifers). They are mainly resinous, aromatic evergreen trees.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Gnetum: A plant genus of the family Gnetaceae, order Gnetales class Gnetopsida, division GNETOPHYTA. Members contain STILBENES and benzylisoquinoline alkaloids.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.Genome, Chloroplast: The genetic complement of CHLOROPLASTS as represented in their DNA.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Bryophyta: A division of the plant kingdom. Bryophyta contains the subdivision, Musci, which contains the classes: Andreaeopsida, BRYOPSIDA, and SPHAGNOPSIDA.Thysanoptera: An order of very small, fringed-wing INSECTS including many agricultural pests.Cunninghamia: A plant genus of the family TAXODIACEAE. Members contain DITERPENES.Pinus sylvestris: A plant species of the genus PINUS which is the source of pinosylvin. It is sometimes called Scotch pine or Scots pine, which is also a common name for other species of this genus.Phloem: Plant tissue that carries nutrients, especially sucrose, by turgor pressure. Movement is bidirectional, in contrast to XYLEM where it is only upward. Phloem originates and grows outwards from meristematic cells (MERISTEM) in the vascular cambium. P-proteins, a type of LECTINS, are characteristically found in phloem.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.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.DNA Shuffling: The use of DNA recombination (RECOMBINATION, GENETIC) to prepare a large gene library of novel, chimeric genes from a population of randomly fragmented DNA from related gene sequences.Viridiplantae: A monophyletic group of green plants that includes all land plants (EMBRYOPHYTA) and all green algae (CHLOROPHYTA and STREPTOPHYTA).Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Extinction, Biological: The ceasing of existence of a species or taxonomic groups of organisms.Cryptomeria: A plant genus of the family TAXODIACEAE. Its POLLEN is one of the major ALLERGENS.Wood: A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.Seed Dispersal: The various physical methods which include wind, insects, animals, tension, and water, by which a plant scatters its seeds away from the parent plant.Flowers: The reproductive organs of plants.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.DNA, Chloroplast: Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.RNA, Plant: Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Expressed Sequence Tags: Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.Diterpenes, Kaurane: A group of DITERPENES cyclized into four rings.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.

Process and current status of the epidemiologic studies on cedar pollinosis in Japan. (1/132)

This paper reviews the present situation and future aspects of epidemiologic studies on Japanese cedar pollinosis. Increase of allergic rhinitis patients is observed in both the Patient Survey and the Reports on the Surveys of Social Medical Care Insurance Services, however, these surveys are conducted when cedar pollens do not pollute the air. Many have reported on the prevalence of pollinosis in limited areas but only a few nationwide epidemiologic surveys have been conducted. Most of the studies were conducted at special medical facilities such as university hospitals. There is a high possibility that patients who visit the specific facilities do not exactly represent the actual number of patients and epidemiologic pictures of pollinosis in Japan. The rapid advances in laboratory test methods may change the diagnostic criteria and increase the number of reported patients. Therefore, the prevalence of Japanese cedar pollinosis in Japan has not been determined yet. Determination of the prevalence of cedar pollinosis and description of the epidemiologic pictures constitute the essential steps toward the control of this clinical entity. Thus it is necessary to conduct an epidemiologic survey on Japanese representative samples with a standardized survey form with clear and concise diagnostic criteria.  (+info)

Genes expressed in Pinus radiata male cones include homologs to anther-specific and pathogenesis response genes. (2/132)

We describe the isolation and characterization of 13 cDNA clones that are differentially expressed in male cones of Pinus radiata (D. Don). The transcripts of the 13 genes are expressed at different times between meiosis and microspore mitosis, timing that corresponds to a burst in tapetal activity in the developing anthers. In situ hybridization showed that four of the genes are expressed in the tapetum, while a fifth is expressed in tetrads during a brief developmental window. Six of the seven cDNAs identified in database searches have striking similarity to genes expressed in angiosperm anthers. Seven cDNAs are homologs of defense and pathogen response genes. The cDNAs identified are predicted to encode a chalcone-synthase-like protein, a thaumatin-like protein, a serine hydrolase thought to be a putative regulator of programmed cell death, two lipid-transfer proteins, and two homologs of the anther-specific A9 genes from Brassica napus and Arabidopsis. Overall, our results support the hypothesis that many of the reproductive processes in the angiosperms and gymnosperms were inherited from a common ancestor.  (+info)

Rapid expansion of microsatellite sequences in pines. (3/132)

Microsatellite persistence time and evolutionary change was studied among five species of pines, which included a pair of closely related species (Pinus sylvestris and Pinus resinosa) in the subgenus Pinus, their relative Pinus radiata, and another closely related species pair (Pinus strobus and Pinus lambertiana) in the subgenus Strobus. The effective population sizes of these species are known to have ranged from the very small bottlenecks of P. resinosa to vast populations of P. sylvestris. This background allowed us to place the microsatellite evolution in a well-defined phylogenetic setting. Of 30 loci originating from P. strobus and P. radiata, we were able to consistently amplify 4 in most of the these pine species. These priming sites had been conserved for over 100 Myr. The four microsatellites were sequenced in the five species. Flanking sequences were compared to establish that the loci were orthologous. All microsatellites had persisted in these species, despite very different population sizes. We found a recent microsatellite duplication: a closely related pair of loci in P. strobus, where the other four species had just one locus. On two independent occasions, the repeat area of this same microsatellite (locus RPS 105a/b) had grown from a very low repeat number to 15 or 17 in the last 10-25 Myr. Other parts of the same compound microsatellite had remained virtually unchanged. Locus PR 4.6 is known to be polymorphic in both P. radiata and P. sylvestris, but the polymorphism in the two species is due to different motifs. The very large pine genomes are highly repetitive, and microsatellite loci also occur as gene families.  (+info)

Seed plant phylogeny: Demise of the anthophyte hypothesis? (4/132)

Recent molecular phylogenetic studies indicate, surprisingly, that Gnetales are related to conifers, or even derived from them, and that no other extant seed plants are closely related to angiosperms. Are these results believable? Is this a clash between molecules and morphology?  (+info)

Seed plant phylogeny inferred from all three plant genomes: monophyly of extant gymnosperms and origin of Gnetales from conifers. (5/132)

Phylogenetic relationships among the five groups of extant seed plants are presently quite unclear. For example, morphological studies consistently identify the Gnetales as the extant sister group to angiosperms (the so-called "anthophyte" hypothesis), whereas a number of molecular studies recover gymnosperm monophyly, and few agree with the morphology-based placement of Gnetales. To better resolve these and other unsettled issues, we have generated a new molecular data set of mitochondrial small subunit rRNA sequences, and have analyzed these data together with comparable data sets for the nuclear small subunit rRNA gene and the chloroplast rbcL gene. All nuclear analyses strongly ally Gnetales with a monophyletic conifers, whereas all mitochondrial analyses and those chloroplast analyses that take into account saturation of third-codon position transitions actually place Gnetales within conifers, as the sister group to the Pinaceae. Combined analyses of all three genes strongly support this latter relationship, which to our knowledge has never been suggested before. The combined analyses also strongly support monophyly of extant gymnosperms, with cycads identified as the basal-most group of gymnosperms, Ginkgo as the next basal, and all conifers except for Pinaceae as sister to the Gnetales + Pinaceae clade. According to these findings, the Gnetales may be viewed as extremely divergent conifers, and the many morphological similarities between angiosperms and Gnetales (e.g., double fertilization and flower-like reproductive structures) arose independently.  (+info)

Phylogeny of seed plants based on all three genomic compartments: extant gymnosperms are monophyletic and Gnetales' closest relatives are conifers. (6/132)

Efforts to resolve Darwin's "abominable mystery"-the origin of angiosperms-have led to the conclusion that Gnetales and various fossil groups are sister to angiosperms, forming the "anthophytes." Morphological homologies, however, are difficult to interpret, and molecular data have not provided clear resolution of relationships among major groups of seed plants. We introduce two sequence data sets from slowly evolving mitochondrial genes, cox1 and atpA, which unambiguously reject the anthophyte hypothesis, favoring instead a close relationship between Gnetales and conifers. Parsimony- and likelihood-based analyses of plastid rbcL and nuclear 18S rDNA alone and with cox1 and atpA also strongly support a gnetophyte-conifer grouping. Surprisingly, three of four genes (all but nuclear rDNA) and combined three-genome analyses also suggest or strongly support Gnetales as derived conifers, sister to Pinaceae. Analyses with outgroups screened to avoid long branches consistently identify all gymnosperms as a monophyletic sister group to angiosperms. Combined three- and four-gene rooted analyses resolve the branching order for the remaining major groups-cycads separate from other gymnosperms first, followed by Ginkgo and then (Gnetales + Pinaceae) sister to a monophyletic group with all other conifer families. The molecular phylogeny strongly conflicts with current interpretations of seed plant morphology, and implies that many similarities between gnetophytes and angiosperms, such as "flower-like" reproductive structures and double fertilization, were independently derived, whereas other characters could emerge as synapomorphies for an expanded conifer group including Gnetales. An initial angiosperm-gymnosperm split implies a long stem lineage preceding the explosive Mesozoic radiation of flowering plants and suggests that angiosperm origins and homologies should be sought among extinct seed plant groups.  (+info)

Detection of intracellular bacteria in the buds of Scotch pine (Pinus sylvestris L.) by in situ hybridization. (7/132)

Bacterial isolates were obtained from pine (Pinus sylvestris L.) tissue cultures and identified as Methylobacterium extorquens and Pseudomonas synxantha. The existence of bacteria in pine buds was investigated by 16S rRNA in situ hybridization. Bacteria inhabited the buds of every tree examined, primarily colonizing the cells of scale primordia and resin ducts.  (+info)

Hot spots, indicator taxa, complementarity and optimal networks of taiga. (8/132)

If hot spots for different taxa coincide, priority-setting surveys in a region could be carried out more cheaply by focusing on indicator taxa. Several previous studies show that hot spots of different taxa rarely coincide. However, in tropical areas indicator taxa may be used in selecting complementary networks to represent biodiversity as a whole. We studied beetles (Coleoptera), Heteroptera, polypores or bracket fungi (Polyporaceae) and vascular plants of old growth boreal taiga forests. Optimal networks for Heteroptera maximized the high overall species richness of beetles and vascular plants, but these networks were least favourable options for polypores. Polypores are an important group indicating the conservation value of old growth taiga forests. Random selection provided a better option. Thus, certain groups may function as good indicators for maximizing the overall species richness of some taxonomic groups, but all taxa should be examined separately.  (+info)

  • However, there was not a molecular phylogeny of gymnosperms represented by extensive sampling at the genus level, and most published phylogenies of this group were constructed based on cytoplasmic DNA markers and/or the multi-copy nuclear ribosomal DNA. (semanticscholar.org)
  • Phylogeny of seed plants based on all three genomic compartments: extant gymnosperms are monophyletic and Gnetales' closest relatives are conifers. (semanticscholar.org)
  • The earliest reliable record of gymnosperms dates their appearance to the Carboniferous period (359-299 million years ago). (openstax.org)
  • Most "gymnosperms" are wind-pollinated except for cycads, which are beetle-pollinated. (washington.edu)
  • The cycads are slow-growing dioecious (species with individuals that are either male or female) gymnosperms, the microsporangia (potential pollen) and megasporangia (potential ovules) occurring on different individual sporophytes. (britannica.com)
  • Combined three- and four-gene rooted analyses resolve the branching order for the remaining major groups-cycads separate from other gymnosperms first, followed by Ginkgo and then (Gnetales + Pinaceae) sister to a monophyletic group with all other conifer families. (pnas.org)
  • The fossil record of gymnosperms includes many distinctive taxa that do not belong to the four modern groups, including seed-bearing trees that have a somewhat fern-like vegetative morphology (the so-called "seed ferns" or pteridosperms. (wikipedia.org)
  • Fossil gymnosperms include many that do not belong to the four modern groups, including the so-called "seed ferns" ( Pteridosperms ) and the "cycadeoids" ( Bennettitales ). (wikipedia.org)
  • Another un‐pine‐like gymnosperm is Ginkgo biloba , the maidenhair tree, the sole remaining representative of a group of important plants of the Mesozoic forests. (cliffsnotes.com)
  • Several features unite Ginkgo with the rest of the gymnosperms, but to which precise lineage-the conifer line or the cycad-is still being debated. (cliffsnotes.com)
  • In "gymnosperms", the sexes are separate, so both male and female sporangia are produced either on the same plant (monoecism) or on separate plants (dioecism). (washington.edu)
  • The study of gymnosperms is essential in order to understand the evolutionary significance and diversity of the plant kingdom. (foyles.co.uk)
  • An initial angiosperm-gymnosperm split implies a long stem lineage preceding the explosive Mesozoic radiation of flowering plants and suggests that angiosperm origins and homologies should be sought among extinct seed plant groups. (pnas.org)
  • Here we have sampled two mitochondrial protein genes, cox 1 (cytochrome oxidase I) and atp A (= atp 1, ATPase I), from all extant seed plant lineages, including all widely recognized gymnosperm families. (pnas.org)
  • Recent focus on plant-insect associations during the angiosperm radiation from the last 30 million years of the Early Cretaceous has inadvertently de-emphasized a similar but earlier diversification that occurred among gymnosperms. (si.edu)
  • Two kinds of higher plants-the gymnosperms and angiosperms-have developed to become the dominant type of land plant. (blogspot.com)
  • This discovery led to the recognition of the progymnosperms as a distinct plant group which completely altered biologists' view of gymnosperm evolution. (blogspot.com)
  • Several issues need to be addressed regarding the evolution of the seed plant genome, and that of the plant genome predating the gymnosperm-angiosperm (GA) divergence. (biomedcentral.com)
  • Evidence of plant-arthropod interactions in three orders of gymnosperms is documented in at least five localities from Lower Permian strata of the Río Genoa Formation (Patagonia, Argentina). (conicet.gov.ar)
  • Unlike bryophytes and pteridophytes, in gymnosperms, the male and the female gametophytes do not have an independent free-living existence. (bankofbiology.com)
  • DNA C-values in land plants (comprising bryophytes, lycophytes, monilophytes, gymnosperms and angiosperms) vary approximately 1000-fold from approx. (nih.gov)
  • Insights into the distribution of C-values in each group of land plants were gained by superimposing available C-value data (4119 angiosperms, 181 gymnosperms, 63 monilophytes, 4 lycophytes and 171 bryophytes) onto phylogenetic trees. (nih.gov)
  • Histograms showing the distribution of DNA C-values for (A) 4119 angiosperms, (B) 181 gymnosperms, (C) 63 monilophytes, (D) 4 lycophytes, and (E) 171 bryophytes. (nih.gov)
  • followed by the range of nuclear DNA C-values encountered in each group or family of (A) angiosperms, (B) gymnosperms, (C) monilophytes and lycophytes, and (D) bryophytes. (nih.gov)
  • A likelihood-based analysis of the evolution of genome size in 165 gymnosperms finds evidence for heterogeneous rates of genome size evolution due to an elevated rate in Pinus . (hindawi.com)
  • Many gymnosperms have exceptionally large genomes (e.g., [ 5 - 7 ]), and this has hindered whole-genome sequencing projects, especially among economically important Pinus species. (hindawi.com)
  • Other studies have quantified patterns of genome size among gymnosperms, especially within Pinus and the other Pinaceae [ 6 , 7 , 11 - 14 ]. (hindawi.com)
  • Fossil records indicate "gymnosperms" originated in the Paleozoic Era, during the middle Devonian Period about 390 million years ago, and reached their greatest diversity during the Mesozoic Era, between 60 to 225 million years ago. (washington.edu)
  • Gymnosperm (Zamites gigas) fossil. (sciencephoto.com)
  • The regeneration hypothesis for gymnosperm exclusion by angiosperms is consistent with several aspects of the fossil record such as the early disappearance of gymnosperms from early successional environments where competition with angiosperms would have been most severe. (deepdyve.com)
  • The earliest fossil of gymnosperms is about 305 million-year-old. (pediaa.com)
  • There is conflicting evidence on the question of whether the living gymnosperms form a clade. (wikipedia.org)
  • Yet the other major clade of seed plants, the gymnosperms, have received far less attention, with few comprehensive studies of diversification and no sequenced genomes. (hindawi.com)
  • As will be discussed in subsequent sections, the various environmental adaptations gymnosperms have represent a step on the path to the most successful (diversity-wise) clade (monophyletic branch). (lumenlearning.com)
  • increases in Santalales and some monocots (both angiosperms), Pinaceae, Sciadopityaceae and Cephalotaxaceae (Gymnosperms) and possibly in the Psilotaceae + Ophioglossaceae clade (monilophytes). (nih.gov)
  • Classification of gymnosperms now recognizes four extant divisions. (britannica.com)
  • Many systems of classification of gymnosperms have been proposed by different authors. (plantlet.org)
  • In early classification schemes, the gymnosperms (Gymnospermae) were regarded as a "natural" group. (wikipedia.org)
  • We assembled a phylogenetic supermatrix containing over 4.5 million nucleotides from 739 gymnosperm taxa. (hindawi.com)
  • This study first synthesizes the available phylogenetically informative sequences to build a phylogenetic hypothesis of gymnosperms that reflects the recent advances in sequencing and computational phylogenetics. (hindawi.com)
  • We constructed a phylogenetic hypothesis of gymnosperms from available, phylogenetically informative sequence data in GenBank that was available on June 30, 2009. (hindawi.com)
  • Phylogenetic analyses of 157 gene families for which at least two duplicates were mapped on the spruce genome indicated that ancient gene duplicates shared by angiosperms and gymnosperms outnumbered conifer-specific duplicates by a ratio of eight to one. (biomedcentral.com)
  • We use the tree to examine large-scale patterns of diversification of the extant gymnosperm lineages and also to examine rates of genome size evolution. (hindawi.com)
  • Evidence has also been found that mid-Mesozoic gymnosperms were pollinated by Kalligrammatid lacewings, a now-extinct genus with members which (in an example of convergent evolution) resembled the modern butterflies that arose far later. (wikipedia.org)
  • Most of the Gymnosperms became extinct in the Cenozoic era (from 65 million years ago to present day). (wikipedia.org)
  • Leaves of the extinct jurassic cycad-like bennettitalean gymnosperm from Yorkshire, UK. (sciencephoto.com)
  • Yet compared to angiosperms, little is known about the patterns of diversification and genome evolution in gymnosperms. (hindawi.com)
  • This large genome size is interesting because one suggested mechanism for rapid increases in genome size, polyploidy, is rare among gymnosperms [ 8 ]. (hindawi.com)
  • These studies have largely focused on finding morphological, biogeographic, or life history correlates of genome size, but the rates and patterns of genome size evolution in gymnosperms are largely unknown. (hindawi.com)
  • The biggest limitation in what we are doing is that there is no published gymnosperm genome," says Prior. (bio-medicine.org)
  • While much light has been shed on the mechanisms and rate of genome evolution in flowering plants, such knowledge remains conspicuously meagre for the gymnosperms. (biomedcentral.com)
  • Are ancient duplicates, those preceding the GA split, relatively more abundant and more translocated through the gymnosperm genome than most recent duplicates specific to the gymnosperms? (biomedcentral.com)
  • Special xylem tissue called "compression wood" is formed on the lower side of inclined stems when gymnosperms grow on a slope. (scirp.org)
  • Unlike other gymnosperms , they possess vessel elements in the xylem. (klinika-trufanovoy.ru)
  • In gymnosperms, seeds are not enclosed in a fruit (naked) and, therefore, ovules are directly borne on megasporophylls. (pediaa.com)
  • These are the characteristic features of Gymnosperms and will be classified under the same. (toppr.com)
14.3 Seed Plants: Gymnosperms - Concepts of Biology | OpenStax
14.3 Seed Plants: Gymnosperms - Concepts of Biology | OpenStax (openstax.org)
Gymnosperms: Features, Classification, Reproduction and Fertilization
Gymnosperms: Features, Classification, Reproduction and Fertilization (toppr.com)
Microspore - Wikipedia
Microspore - Wikipedia (en.wikipedia.org)
Fertilisation - Wikipedia
Fertilisation - Wikipedia (en.wikipedia.org)
Microsporangium | plant anatomy | Britannica
Microsporangium | plant anatomy | Britannica (britannica.com)
Project MUSE - Plants of Deep South Texas
Project MUSE - Plants of Deep South Texas (muse.jhu.edu)
Plant stem - Wikipedia
Plant stem - Wikipedia (en.wikipedia.org)
Introduction to Plants: Terms | SparkNotes
Introduction to Plants: Terms | SparkNotes (sparknotes.com)
What Are Characteristics of Flowering Plants? | Reference.com
What Are Characteristics of Flowering Plants? | Reference.com (reference.com)
The solubility of Pb(IO3)(s) in a 0.10-M KIO3 solution | bartleby
The solubility of Pb(IO3)(s) in a 0.10-M KIO3 solution | bartleby (bartleby.com)
Gymnosperm - Simple English Wikipedia, the free encyclopedia
Gymnosperm - Simple English Wikipedia, the free encyclopedia (simple.wikipedia.org)
View the content page [c]
View the content page [c] (let.rug.nl/~gosse/)
Types of trees
Types of trees (botanical-online.com)
Associate Professor David Collings / Staff Profile / The University of Newcastle, Australia
Associate Professor David Collings / Staff Profile / The University of Newcastle, Australia (newcastle.edu.au)
Pinophyta - Wikipedia
Pinophyta - Wikipedia (en.wikipedia.org)
Embryophyte - Wikipedia
Embryophyte - Wikipedia (en.wikipedia.org)
Almond - Wikipedia
Almond - Wikipedia (en.wikipedia.org)
Canarium ovatum - Wikipedia
Canarium ovatum - Wikipedia (en.wikipedia.org)
Pine nut - Wikipedia
Pine nut - Wikipedia (en.wikipedia.org)
Stone pine - Wikipedia
Stone pine - Wikipedia (en.wikipedia.org)
Ancient beetle discovery gives clue to gymnosperm pollination | EurekAlert! Science News
Ancient beetle discovery gives clue to gymnosperm pollination | EurekAlert! Science News (eurekalert.org)
Genome-wide comparative and evolutionary analysis of Calmodulin-binding Transcription Activator (CAMTA) family in Gossypium...
Genome-wide comparative and evolutionary analysis of Calmodulin-binding Transcription Activator (CAMTA) family in Gossypium... (nature.com)
Plants of the World: An Illustrated Encyclopedia of Vascular Plants, Christenhusz, Fay, Chase
Plants of the World: An Illustrated Encyclopedia of Vascular Plants, Christenhusz, Fay, Chase (press.uchicago.edu)
Integument - Reptiles | Britannica.com
Integument - Reptiles | Britannica.com (britannica.com)
Koeltz Botanical Books. Libya
Koeltz Botanical Books. Libya (koeltz.com)
Research | Pyhäjärvi Lab
Research | Pyhäjärvi Lab (oulu.fi)
SSENH901/MG012: Botany Handbook for Florida
SSENH901/MG012: Botany Handbook for Florida (edis.ifas.ufl.edu)
New flora british isles 3rd edition | Botanical reference | Cambridge University Press
New flora british isles 3rd edition | Botanical reference | Cambridge University Press (cambridge.org)
Populus alba - Wikipedia
Populus alba - Wikipedia (en.wikipedia.org)
Angiosperm - Significance to humans | Britannica.com
Angiosperm - Significance to humans | Britannica.com (britannica.com)
Characteristics of different phyla of plantae.
Characteristics of different phyla of plantae. (indiastudychannel.com)
Pollen Grain: Definition, Structure & Function - Video & Lesson Transcript | Study.com
Pollen Grain: Definition, Structure & Function - Video & Lesson Transcript | Study.com (study.com)
Archaeopteris | fossil plant genus | Britannica.com
Archaeopteris | fossil plant genus | Britannica.com (britannica.com)
Six Kingdom System of Classification by Hiba Chughtai on Prezi
Six Kingdom System of Classification by Hiba Chughtai on Prezi (prezi.com)
Introduction
Introduction (mobot.org)