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Flowering
Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, modified leaves; corolla, the petals; androecium, the male reproductive unit consisting of stamens and pollen; and gynoecium, the female part, containing style and stigma, which receives the pollen at the tip of the style, and ovary, which contains the ovules. When flowers are arranged in groups, they are known collectively as inflorescences. Floral growth originates at stem tips and is controlled by MADS-box genes. In most plant species flowers are heterosporous, and so can produce sex cells of both sexes. Pollination mediates the transport of pollen to the ovules in the ovaries, to facilitate sexual reproduction. It can occur between different plants, as in cross-pollination, or between flowers on the same plant or even the same flowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. The group was formerly called Magnoliophyta. Angiosperms are by far the most diverse group of Embryophyte, land plants with 64 Order (biology), orders, 416 Family (biology), families, approximately 13,000 known Genus, genera and 300,000 known species. They include all forbs (flowering plants without a woody Plant stem, stem), grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. Angiosperms are distinguished from the other major seed plant clade, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from the commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Style (botany)
In botany, the style of an angiosperm flower is an organ of variable length that connects the ovary to the stigma. The style does not contain ovules; these are limited to the region of the gynoecium (female organs of the flower) called the "ovary". Structure The style is a narrow extension of the ovary, usually pointing upwards, connecting the ovary to the stigmatic papillae. It may be absent in some plants; in this case, it is referred to as a sessile stigma. Styles generally resemble more or less long tubes. The style can be open (with few cells occupying the central part, or even none), featuring a central canal that may be filled with mucilage. Alternatively, the style can be closed (completely filled with cells). Most plants with syncarpous pistils ( monocotyledons and some eudicotys) have open styles, whereas many eudicots and grasses have closed (solid) styles containing specialized secretory tissues, which connect the stigma to the center of the ovary. These tissu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or butterflies; birds, and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants. Self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid (biology), hybrid offspring in nature and in plant breeding work. In angiosperms, after the pollen grain (gametophyte) has landed on the stigma (botany), stigma, it germinates and develops a pollen tube which grows down the style (botany), style until it reaches an ovary (botany), ovary. Its two gametes travel down ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stamen
The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament and an anther which contains sporangium, microsporangia. Most commonly, anthers are two-lobed (each lobe is termed a locule) and are attached to the filament either at the base or in the middle area of the anther. The sterile (i.e. nonreproductive) tissue between the lobes is called the Connective (botany), connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The size of anthers differs greatly, from a tiny fraction of a millimeter in ''Wolfia'' spp up to five inches (13 centimeters) in ''Canna iridiflora'' and ''Strelitzia nicolai''. The stamens in a flower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. In placental mammals, sperm cells exit the penis through the male urethra and enter the vagina during copulation, while egg cells enter the uterus through the oviduct. Other vertebrates of both sexes possess a cloaca for the release of sperm or egg cells. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stigma (botany)
The stigma (: stigmas or stigmata) is the receptive tip of a Gynoecium#Carpels, carpel, or of several fused carpels, in the gynoecium of a flower. Description The stigma, together with the Style (botany), style and ovary (botany), ovary (typically called the stigma-style-ovary system) comprises the pistil, which is part of the gynoecium or female reproductive organ of a plant. The stigma itself forms the distal portion of the style, or stylodia, and is composed of , the cells of which are receptive to pollen. These may be restricted to the apex of the style or, especially in wind pollinated species, cover a wide surface. The stigma receives pollen and it is on the stigma that the pollen grain germination, germinates. Often sticky, the stigma is adapted in various ways to catch and trap pollen with various hairs, flaps, or sculpturings. The pollen may be captured from the air (wind-borne pollen, anemophily), from visiting insects or other animals (Pollination syndrome#Biotic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnolia Grandiflora
''Magnolia grandiflora'', commonly known as the southern magnolia or bull bay, is a tree of the family Magnoliaceae native to the Southeastern United States, from Virginia to central Florida, and west to East Texas. Reaching in height, it is a large, striking evergreen tree, with large, dark-green leaves up to long and wide, and large, white, fragrant flowers up to in diameter. Although endemic to the evergreen lowland subtropical forests on the Gulf and South Atlantic coastal plain, ''M. grandiflora'' is widely cultivated in warmer areas around the world. The timber is hard and heavy, and has been used commercially to make furniture, pallets, and veneer. Description ''Magnolia grandiflora'' is a medium to large evergreen tree which may grow tall.Gardiner, p. 144 It typically has a single stem (or trunk) and a Pyramid (geometry), pyramidal shape. The leaf, leaves are simple and broadly ovate, long and broad, with smooth margins. They are dark green, stiff, and leathery, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilisation
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or offspring. While processes such as insemination or pollination, which happen before the fusion of gametes, are also sometimes informally referred to as fertilisation, these are technically separate processes. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms, the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Plant
A seed plant or spermatophyte (; New Latin ''spermat-'' and Greek ' (phytón), plant), also known as a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae. The term ''phanerogam'' or ''phanerogamae'' is derived from the Greek (), meaning "visible", in contrast to the term "cryptogam" or " cryptogamae" (, and (), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae). Description The extant spermatophytes form five divisions, the first four of which are classified as gymnosperms, plants that have unenclosed, "naked seeds": * Cycadophyta, the cycads, a subtropical and tropical group of plants, * Ginkgophyta, which includes a single living species of tree in the genus '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zea Mays
Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout Poaceae, grass that produces cereal grain. It was domesticated by indigenous peoples of Mexico, indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native Americans planted it alongside beans and Cucurbita, squashes in the Three Sisters (agriculture), Three Sisters polyculture. The leafy Plant stem, stalk of the plant gives rise to male inflorescences or tassels which produce pollen, and female inflorescences called ear (botany), ears. The ears yield grain, known as Corn kernels, kernels or seeds. In modern commercial varieties, these are usually yellow or white; other varieties can be of many colors. Maize relies on humans for its propagation. Since the Columbian exchange, it has become a staple food in many parts of the world, with the List of most valuable crops and livestock products, total production of maize surpassing that of wheat and rice. Much maize is u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MADS-box
The MADS box is a conserved sequence motif. The genes which contain this motif are called the MADS-box gene family. The MADS box encodes the DNA-binding MADS domain. The MADS domain binds to DNA sequences of high similarity to the motif CC[A/T]6GG termed the CArG-box. MADS-domain proteins are generally transcription factors. The length of the MADS-box reported by various researchers varies somewhat, but typical lengths are in the range of 168 to 180 base pairs, i.e. the encoded MADS domain has a length of 56 to 60 amino acids. There is evidence that the MADS domain evolved from a sequence stretch of a type II topoisomerase in a common ancestor of all extant eukaryotes. Origin of name and history of research The first MADS-box gene to be identified was ''ARG80'' from budding yeast, ''Saccharomyces cerevisiae'', but was at that time not recognized as a member of a large gene family. The MADS-box gene family got its name later as an acronym referring to the four founding members, ig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed
In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilization, fertilized by Pollen, sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted. The formation of the seed is the defining part of the process of reproduction in seed plants (spermatophytes). Other plants such as ferns, mosses and marchantiophyta, liverworts, do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological Ecological niche, niches on land, from forests to grasslands both in hot and cold climates. In the flowering plants, the ovary ripens into a fruit which contains the seed and serves to disseminate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
