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Synergid
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center. The female gametophyte — specifically termed a ''megagametophyte''— is also called the ''embryo sac'' in angiosperms. The megagametophyte produces an egg cell for the purpose of fertilization. The ovule is a small structure present in the ovary. It is attached to the placenta by a stalk called a funicle. The funicle provides nourishment to the ovule. Location within the plant In flowering plants, the ovule is located inside the portion of the flower called the gynoecium. The ovary of the gynoecium produces one or more ovules and ultimately becomes the fruit wall. Ovules are attached to the placenta in the ovary through a stalk-like structure known as a ''funiculus'' (pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovules In Flower
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the '' integument'', forming its outer layer, the '' nucellus'' (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center. The female gametophyte — specifically termed a ''megagametophyte''— is also called the ''embryo sac'' in angiosperms. The megagametophyte produces an egg cell for the purpose of fertilization. The ovule is a small structure present in the ovary. It is attached to the placenta by a stalk called a funicle. The funicle provides nourishment to the ovule. Location within the plant In flowering plants, the ovule is located inside the portion of the flower called the gynoecium. The ovary of the gynoecium produces one or more ovules and ultimately becomes the fruit wall. Ovules are attached to the placenta in the ovary through a stalk-like structure known as a ''funi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are positione ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucellus
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the '' integument'', forming its outer layer, the '' nucellus'' (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center. The female gametophyte — specifically termed a ''megagametophyte''— is also called the ''embryo sac'' in angiosperms. The megagametophyte produces an egg cell for the purpose of fertilization. The ovule is a small structure present in the ovary. It is attached to the placenta by a stalk called a funicle. The funicle provides nourishment to the ovule. Location within the plant In flowering plants, the ovule is located inside the portion of the flower called the gynoecium. The ovary of the gynoecium produces one or more ovules and ultimately becomes the fruit wall. Ovules are attached to the placenta in the ovary through a stalk-like structure known as a ''funicu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gametophyte
A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the Sexual reproduction of plants, sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte. The sporophyte can produce haploid spores by meiosis that on germination produce a new generation of gametophytes. Algae In some multicellular green algae (''Ulva lactuca'' is one example), red algae and brown algae, sporophytes and gametophytes may be externally indistinguishable (isomorphic). In ''Ulva (genus), Ulv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaspore
Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. These plants have two spore types, megaspores and microspores. Generally speaking, the megaspore, or large spore, germinates into a female gametophyte, which produces egg cells. These are fertilized by sperm produced by the male gametophyte developing from the microspore. Heterosporous plants include seed plants (gymnosperms and flowering plants), water ferns (Salviniales), spikemosses ( Selaginellaceae) and quillworts ( Isoetaceae). Megasporogenesis In gymnosperms and flowering plants, the megaspore is produced inside the nucellus of the ovule. During megasporogenesis, a diploid precursor cell, the megasporocyte or megaspore mother cell, undergoes meiosis to produce initially four haploid cells (the megaspores). Angiosperms exhibit three patterns of megasporogenesis: monosporic, bisporic, and tetrasporic, also known as the ''Polygonum'' type, the ''Alisma'' type, and the ''Drusa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. The term "angiosperm" is derived from the Greek words ἀγγεῖον / ('container, vessel') and σπέρμα / ('seed'), meaning that the seeds are enclosed within a fruit. They are by far the most diverse group of land plants with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. Angiosperms were formerly called Magnoliophyta (). Angiosperms are distinguished from the other seed-producing plants, 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 common ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helianthus
''Helianthus'' () is a genus comprising about 70 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. Except for three South American species, the species of ''Helianthus'' are native to North America and Central America. The best-known species is the common sunflower (''Helianthus annuus''), whose round flower heads in combination with the ligules look like the Sun. This and other species, notably Jerusalem artichoke (''H. tuberosus''), are cultivated in temperate regions and some tropical regions, as food crops for humans, cattle, and poultry, and as ornamental plants. The species ''H. annuus'' typically grows during the summer and into early fall, with the peak growth season being mid-summer. Several perennial ''Helianthus'' species are grown in gardens, but have a tendency to spread rapidly and can become aggressive. On the other hand, the whorled sunflower, ''Helianthus verticillatus'', was listed as an endangere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compositae
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. Most species of Asteraceae are annual, biennial, or perennial herbaceous plants, but there are also shrubs, vines, and trees. The family has a widespread distribution, from subpolar to tropical regions in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates, and they are found on every continent but Antarctica. The primary common characteristic is the existence of sometimes hundreds of tiny individual florets which are held together by protective involucres in flower heads, or more technically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellaria
''Stellaria'' is a genus of about 190 species of flowering plants in the family Caryophyllaceae, with a cosmopolitan distribution. Common names include starwort, stitchwort and chickweed. Description ''Stellaria'' species are relatively small herbs with simple opposite leaves. It produces small flowers with 5 sepals and 5 white petals each usually deeply cleft, or none at all, all free. Stamens 10 or fewer. Uses Some species, including ''Stellaria media'' which is widely distributed throughout the Northern Hemisphere, are used as leaf vegetables, often raw in salads. This is a favored food of finches and many other seed-eating birds. Chickweeds are used as food plants by the larvae of some Lepidoptera species including angle shades, heart and dart, riband wave, setaceous Hebrew character and the '' Coleophora'' case-bearers ''C. coenosipennella'' (feeds exclusively on ''Stellaria'' species), ''C. lineolea'' (recorded on ''S. graminea''), ''C. lithargyrinella'' (rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dianthus
''Dianthus'' () is a genus of about 340 species of flowering plants in the family Caryophyllaceae, native mainly to Europe and Asia, with a few species in north Africa and in southern Africa, and one species (''D. repens'') in arctic North America. Common names include carnation (''D. caryophyllus''), pink (''D. plumarius'' and related species) and sweet william (''D. barbatus''). Description The species are mostly herbaceous perennials, a few are annual or biennial, and some are low subshrubs with woody basal stems. The leaves are opposite, simple, mostly linear and often strongly glaucous grey green to blue green. The flowers have five petals, typically with a frilled or pinked margin, and are (in almost all species) pale to dark pink. One species, ''D. knappii'', has yellow flowers with a purple centre. Some species, particularly the perennial pinks, are noted for their strong spicy fragrance. Species Selected species include: Hybrids include; * 'Devon Xera' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brassica
''Brassica'' () is a genus of plants in the cabbage and mustard family (Brassicaceae). The members of the genus are informally known as cruciferous vegetables, cabbages, or mustard plants. Crops from this genus are sometimes called ''cole crops''derived from the Latin ''caulis'', denoting the stem or stalk of a plant. The genus ''Brassica'' is known for its important agricultural and horticultural crops and also includes a number of weeds, both of wild taxa and escapees from cultivation. ''Brassica'' species and varieties commonly used for food include bok choy, broccoli, cauliflower, cabbage, choy sum, kohlrabi, napa cabbage, rutabaga, turnip and some seeds used in the production of canola oil and the condiment mustard. Over 30 wild species and hybrids are in cultivation, plus numerous cultivars and hybrids of cultivated origin. Most are seasonal plants ( annuals or biennials), but some are small shrubs. ''Brassica'' plants have been the subject of much scientifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
