Search results
Results From The WOW.Com Content Network
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 ]
Once the sperm has matured, the sperm requires water, such as raindrops, to help carry the sperm from an antheridium to an egg located in an archegonium on a female gametophyte shoot. The perigonium structure is composed of an antheridium, paraphyses (sterile filaments that support the reproductive structure of bryophytes), [14] and perigonial ...
The corresponding male organ is called the antheridium. The archegonium has a long neck canal or venter and a swollen base. The archegonium has a long neck canal or venter and a swollen base. Archegonia are typically located on the surface of the plant thallus , although in the hornworts they are embedded.
However, in ferns and their allies there are groups with undifferentiated spores but differentiated gametophytes. For example, the fern Ceratopteris thalictrioides has spores of only one kind, which vary continuously in size. Smaller spores tend to germinate into gametophytes which produce only sperm-producing antheridia.
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 egg cells. Antheridia are common in the gametophytes in "lower" plants such as bryophytes , ferns , cycads and ginkgo .
The sex organs are developed in pairs from the adaxial nodal cell at the upper nodes of the primary lateral branches, the oogonium being formed above the antheridium. They are sufficiently large to be easily seen with the naked eye, especially the bright orange or red antheridium. Many species are dioecious.
First named Oedogoniaceen (in German), the name Oedogoniales is derived from the Latin oedos (meaning swelling or tumor) and gonos (meaning offspring or seed). This name describes the morphology that Hirn witnessed during Oedogonium sexual and asexual reproduction and later described in his publication, “Monographie und iconographie der Oedogoniaceen."
At the apex of the main plant axis, the antheridium is borne. This is the male part of the shoot. A lateral branch from the main plant axis bears the female shoot archegonium at its meristem. Experiments have shown that F. hygrometrica can withstand water with 90% heavy water. [3]