Search results
Results From The WOW.Com Content Network
In bryophytes and other cryptogams, sperm reach the archegonium by swimming in water films, whereas in Pinophyta and angiosperms, the pollen are delivered by wind or animal vectors and the sperm are delivered by means of a pollen tube. [citation needed] Gene expression pattern determined by histochemical GUS assays in Physcomitrella patens
Archegoniatae was a higher taxonomic term that indicated those embryophytes having a female sexual organ in the form of an archegonium.The term was first introduced by the Russian botanist Ivan Nikolaevich Gorozhankin (1848–1904) in 1876 to indicate a division including bryophytes, pteridophytes and gymnosperms in contrast to the Gynoeciatae (Angiosperms) with a more complex female organ.
The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. [1] The androecium is also the collective term for the stamens of flowering plants. Antheridia are present in the gametophyte phase of cryptogams like bryophytes and ferns. [2]
The archegonia are small flask-shaped clumps of cells with an open neck (venter) down which the male sperm swim. The male organs are known as antheridia (sing. antheridium) and are enclosed by modified leaves called the perigonium (pl. perigonia). The surrounding leaves in some mosses form a splash cup, allowing the sperm contained in the cup ...
Antheridia producing non-motile sperm (spermatia) are called spermatangia. Some antheridia do not release their sperm. Some antheridia do not release their sperm. For example, the oomycete antheridium is a syncytium with many sperm nuclei and fertilization occurs via fertilization tubes growing from the antheridium and making contact with the ...
Antheridia and archegonia occur on the same gametophyte, which is then called monoicous. (Many sources, including those concerned with bryophytes, use the term 'monoecious' for this situation and 'dioecious' for the opposite. [23] [24] Here 'monoecious' and 'dioecious' are used only for sporophytes.)
An example of moss (Bryophyta) on the forest floor in Broken Bow, Oklahoma. Bryophytes (/ ˈ b r aɪ. ə ˌ f aɪ t s /) [2] are a group of land plants (embryophytes), sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts, and mosses. [3]
In bryophytes and pteridophytic land plants, fertilisation of the sperm and egg takes place within the archegonium. In seed plants, the male gametophyte is formed within a pollen grain. After pollination, the pollen grain germinates, and a pollen tube grows and penetrates the ovule through a tiny pore called a micropyle. The sperm are ...