when you combine an egg with the material in pollen you get double fertilization.
when you combine an egg with the material in pollen you get double fertilization.
when you combine an egg with the material in pollen you get?
double fertilization
once a pollen grain settles on a compatible pistil, it may germinate in response to a sugary fluid secreted by the mature stigma. lipids at the surface of the stigma may also stimulate pollen tube growth for compatible pollen. plants that are self-sterile often inhibit the pollen grains from their own flowers from growing pollen tubes. the presence of multiple grains of pollen has been observed to stimulate quicker pollen tube growth in some plants. the vegetative cell then produces the pollen tube, a tubular protrusion from the pollen grain, which carries the sperm cells within its cytoplasm. the sperm cells are the male gametes that will join with the egg cell and the central cell in double fertilization. the first fertilization event produces a diploid zygote and the second fertilization event produces a triploid endosperm.
pollen tube
most major classes of predatory and parasitic arthropods contain species that eat pollen, despite the common perception that bees are the primary pollen-consuming arthropod group. many other hymenoptera other than bees consume pollen as adults, though only a small number feed on pollen as larvae (including some ant larvae). spiders are normally considered carnivores but pollen is an important source of food for several species, particularly for spiderlings, which catch pollen on their webs. it is not clear how spiderlings manage to eat pollen however, since their mouths are not large enough to consume pollen grains. some predatory mites also feed on pollen, with some species being able to subsist solely on pollen, such as "euseius tularensis", which feeds on the pollen of dozens of plant species. members of some beetle families such as mordellidae and melyridae feed almost exclusively on pollen as adults, while various lineages within larger families such as curculionidae, chrysomelidae, cerambycidae, and scarabaeidae are pollen specialists even though most members of their families are not (e.g., only 36 of 40,000 species of ground beetles, which are typically predatory, have been shown to eat pollen—but this is thought to be a severe underestimate as the feeding habits are only known for 1,000 species). similarly, ladybird beetles mainly eat insects, but many species also eat pollen, as either part or all of their diet. hemiptera are mostly herbivores or omnivores but pollen feeding is known (and has only been well studied in the anthocoridae). many adult flies, especially syrphidae, feed on pollen, and three uk syrphid species feed strictly on pollen (syrphids, like all flies, cannot eat pollen directly due to the structure of their mouthparts, but can consume pollen contents that are dissolved in a fluid). some species of fungus, including "fomes fomentarius", are able to break down grains of pollen as a secondary nutrition source that is particularly high in nitrogen. pollen may be valuable diet supplement for detritivores, providing them with nutrients needed for growth, development and maturation. it was suggested that obtaining nutrients from pollen, deposited on the forest floor during periods of pollen rains, allows fungi to decompose nutritionally scarce litter.
pollen