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In vitro double fertilization is often used to study the molecular interactions as well as other aspects of gamete fusion in flowering plants. One of the major obstacles in developing an in vitro double fertilization between male and female gametes is the confinement of the sperm in the pollen tube and the egg in the embryonic sac.
Flowering plants contain non-motile sperm inside pollen, while some more basal plants like ferns and some gymnosperms have motile sperm. [2] Sperm cells form during the process known as spermatogenesis, which in amniotes (reptiles and mammals) takes place in the seminiferous tubules of the testicles. [3]
Allogamy, which is also known as cross-fertilisation, refers to the fertilisation of an egg cell from one individual with the male gamete of another. Autogamy which is also known as self-fertilisation, occurs in such hermaphroditic organisms as plants and flatworms; therein, two gametes from one individual fuse.
An antheridium is a haploid structure or organ producing and containing male gametes (called antherozoids or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. [1] Androecium is also the collective term for the stamens of flowering plants.
A gametangium (pl.: gametangia) is a sex organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants. In contrast to gametogenesis in animals , a gametangium is a haploid structure and formation of gametes does not involve meiosis .
The smaller gamete is considered to be male (a sperm cell), whereas the larger gamete is regarded as female (typically an egg cell, if non-motile). [13] [14] There are several types of anisogamy. Both gametes may be flagellated and therefore motile. Alternatively, as in flowering plants, conifers and gnetophytes, neither of the gametes are ...
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.
The name gamete was introduced by the German cytologist Eduard Strasburger in 1878. [3] Gametes of both mating individuals can be the same size and shape, a condition known as isogamy. By contrast, in the majority of species, the gametes are of different sizes, a condition known as anisogamy or heterogamy that applies to humans and other ...