Search results
Results From The WOW.Com Content Network
Once mature, this single celled gametophyte is 90% smaller than the female gametophytes in other gymnosperm orders. [14] After fertilization, the remaining female gametophyte tissue in gymnosperms serves as the nutrient source for the developing zygote (even in Gnetophyta where the diploid zygote cell is much smaller at that stage, and for a ...
A mature sporophyte produces haploid spores by meiosis, a process which reduces the number of chromosomes to half, from two sets to one. The resulting haploid spores germinate and grow into multicellular haploid gametophytes.
One study performed on the fern species Woodwardia radicans found that sex expression of mature gametophytes is dependent on stress conditions. [10] In good conditions, gametophytes reached sexual maturity at a larger size and became females and then bisexuals, whereas in stressful conditions, gametophytes reached sexual maturity at a smaller ...
Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes.Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic division of diploid gametocytes into various gametes, or by mitosis.
The mature sporophyte produces spores by meiosis, sometimes referred to as reduction division because the chromosome pairs are separated once again to form single sets. In mosses and liverworts, the gametophyte is relatively large, and the sporophyte is a much smaller structure that is never separated from the gametophyte.
The mature gametophyte produces male or female gametes (or both) by mitosis. The fusion of male and female gametes produces a diploid zygote which develops into a new sporophyte. This cycle is known as alternation of generations or alternation of phases.
Megagametogenesis is the process of maturation of the female gametophyte, or megagametophyte, in plants. [1] During the process of megagametogenesis, the megaspore, which arises from megasporogenesis, develops into the embryonic sac, in which the female gamete is housed. [2]
Bryophytes have 2 flagella, horsetails have up to 200 and the mature spermatozoa of the cycad Zamia pumila has up to 50,000 flagella. [18] Cycads and Ginkgo biloba are the only gymnosperms with motile sperm. [17] In the flowering plants, the female gametophyte is produced inside the ovule within the ovary of the flower. When mature, the haploid ...