When we talk about plant reproduction, we often hear the expressions antheridium and archegon. But, after all, what are these structures?
O antheridium it is responsible for the production of the male gametes known as anterozoids. They can be single or multicellular, depending on the studied group.
In bryophytes, antheridium is elongated or spherical, has an outer layer of sterile cells and, in its interior, spermatogen cells are found, which give rise to anterozoids. Each spermatogen cell forms only one flagellated anterozoid. In pteridophytes, antheridia are located in the rhizoids of the prothalus and appear in the shape of a pouch lined with sterile cells.
The figure above shows the archegon of a liverwort at 100x magnification
You archegons they are multicellular structures that produce only one oosphere (female gamete)—an immobile structure, unlike anterozoids.
In bryophytes, the archegon is bottle-shaped, with a dilated basal portion that houses the oosphere. There is also a long neck that serves as a passage for the anterozoids to reach the oosphere. When the female gamete is mature, the central cells in the cervix disintegrate and form a fluid that allows the passage of the male gamete. In pteridophytes, archegons are formed close to the prothalus recesses and are similar to those of bryophytes.
You antherids and archegones are found in bryophytes and pteridophytes. Gymnosperms have archegones, but no antheridia. Angiosperms do not have any of these structures.
By Ma. Vanessa dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-e-anteridio-arquegonio.htm
