Search results
Results from the WOW.Com Content Network
The female gametophyte in gymnosperms differs from the male gametophyte as it spends its whole life cycle in one organ, the ovule located inside the megastrobilus or female cone. [14] Similar to the male gametophyte, the female gametophyte normally is fully dependent on the surrounding sporophytic tissue for nutrients and the two organisms ...
The sporophyte of a flowering plant is often described using sexual terms (e.g. "female" or "male") based on the sexuality of the gametophyte it gives rise to. For example, a sporophyte that produces spores that give rise only to male gametophytes may be described as "male", even though the sporophyte itself is asexual, producing only spores.
The male reproductive structures of Polytrichum juniperinum. The sporophyte of Polytrichum juniperinum. It is a dioecious plant, meaning that the male and female gametophytes are on separate plants. Juniper haircap moss have very obvious male and female parts.
The transfer of pollen (the male gametophytes) to the female stigmas occurs is called pollination. After pollination occurs, the pollen grain germinates to form a pollen tube that grows through the carpel's style and transports male nuclei to the ovule to fertilize the egg cell and central cell within the female gametophyte in a process termed ...
Megaspores contain the female gametophytes in heterosporic plant species. They develop archegonia that produce egg cells that are fertilized by sperm of the male gametophyte originating from the microspore. This results in the formation of a fertilized diploid zygote, that develops into the sporophyte embryo. While heterosporous plants produce ...
In other phyla of gymnosperms, the Coniferophyta and Gnetophyta, the sperm is non motile, and the pollen tube delivers the sperm to the egg directly, in a process called siphonogamy. Conifers can be branched or unbranched and they cause degeneration of the female tissue as it grows through more tissue.
The male gametophyte is produced inside a pollen grain within the anther and is non-motile, but can be distributed by wind, water or animal vectors. When a pollen grain lands on a mature stigma of a flower it germinates to form a pollen tube that grows down the style into the ovary of the flower and then into the ovule.
The sexuality of pteridophyte gametophytes can be classified as follows: Dioicous: each individual gametophyte is either male (producing antheridia and hence sperm) or female (producing archegonia and hence egg cells). Monoicous: each individual gametophyte produces both antheridia and archegonia and can function both as a male and as a female.