comment on the life cycle and
nature of a fern prothallous
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The diploid sporophyte is represented by a dominant, independent, photosynthetic, vascular plant body. It alternates with multicellular, saprophytic/autotrophic, independent but short-lived haploid gametophyte . called prothallus. Such a pattern is known as haplo-diplontic life cycle. All Pteridophytes exhibit this pattern. These gametophytes require cool, damp, shady places to grow. Because of this specific restricted requirement and the need of water for fertilisation, the spread of living pteridophytes is limited and restricted to narrow geographical regions. The gametophytes (prothallus) bear male and female sex organs ‘ called antheridia and archegonia, respectively. Water is required for transfer of antherozoids-the male gametes released from the antheridia, to the mouth of archegonium. Fusaion of male gamete … with the egg present in the archegonium result in the fonnation of zygote. Zygote thereafter produces a multicellular well-differentiated sporophyte which is the dominant phase of the pteridophytes.