Search results
Results From The WOW.Com Content Network
This is an accepted version of this page This is the latest accepted revision, reviewed on 22 January 2025. Union of gametes of opposite sexes during the process of sexual reproduction to form a zygote This article is about fertilisation in animals and plants. For fertilisation in humans specifically, see Human fertilization. For soil improvement, see Fertilizer. "Conceive" redirects here. For ...
Location of ovules inside a Helleborus foetidus 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.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes , resulting in offspring genetically different from either parent.
A controlled fusion of the egg and sperm has already been achieved with poppy plants. [16] Pollen germination, pollen tube entry, and double fertilization processes have all been observed to proceed normally. In fact, this technique has already been used to obtain seeds in various flowering plants and was named “test-tube fertilization”. [17]
A fruit is the mature, ripened ovary of a flower following double fertilization in an angiosperm.Because gymnosperms do not have an ovary but reproduce through fertilization of unprotected ovules, they produce naked seeds that do not have a surrounding fruit, this meaning that juniper and yew "berries" are not fruits, but modified cones.
Plants may either self-pollinate or cross-pollinate. In 2013, flowers dating from the Cretaceous (100 million years before present) were found encased in amber, the oldest evidence of sexual reproduction in a flowering plant. Microscopic images showed tubes growing out of pollen and penetrating the flower's stigma.
In plants, the zygote may be polyploid if fertilization occurs between meiotically unreduced gametes. In land plants, the zygote is formed within a chamber called the archegonium. In seedless plants, the archegonium is usually flask-shaped, with a long hollow neck through which the sperm cell enters.
The evolutionary shift from outcrossing to self-fertilization is one of the most frequent evolutionary transitions in plants. Since autogamy in flowering plants and autogamy in unicellular species is fundamentally different, and plants and protists are not related, it is likely that both instances evolved separately.