Name threegroups of plants that bear archegonia. Briefly describe the lifecycle of any one of them.
Name threegroups of plants that bear archegonia. Briefly describe the lifecycle of any one of them.
Archegoniumis the female sex organ that produces the female gamete or egg. It ispresent in the life cycles of bryophytes, pteridophytes, andgymnosperms.
Lifecycle of a fern (Dryopteris)
Dryopterisis a common fern with pinnately-compound leaves. The main plant-bodyis sporophytic. Many sporangia are borne on the lower surfaces of itsmature leaves. Each sporangium has spore mother cells which undergomeiosis to produce haploid spores. On maturing, these spores dehisceand germinate to give rise to a heart-shaped gametophyte calledprothallus.
Theprothallus bears the male and female sex organs called antheridia andarchegonia respectively. The antheridia produce sperms that swim inwater to reach the archegonia. The egg is produced by the archegonia.As a result of fertilisation, a zygote is formed. The zygote forms anembryo, which in turn develops into a new sporophyte. The young plantcomes out of the archegonium of the parent gametophyte.
Archegoniumis the female sex organ that produces the female gamete or egg. It ispresent in the life cycles of bryophytes, pteridophytes, andgymnosperms.
Lifecycle of a fern (Dryopteris)
Dryopterisis a common fern with pinnately-compound leaves. The main plant-bodyis sporophytic. Many sporangia are borne on the lower surfaces of itsmature leaves. Each sporangium has spore mother cells which undergomeiosis to produce haploid spores. On maturing, these spores dehisceand germinate to give rise to a heart-shaped gametophyte calledprothallus.
Theprothallus bears the male and female sex organs called antheridia andarchegonia respectively. The antheridia produce sperms that swim inwater to reach the archegonia. The egg is produced by the archegonia.As a result of fertilisation, a zygote is formed. The zygote forms anembryo, which in turn develops into a new sporophyte. The young plantcomes out of the archegonium of the parent gametophyte.
