Question:
Comment on the lifecycle and nature of a fern prothallus.
Solution:
1. Fern shows diplo-haplontic life cycle.
2. Diploid sporophyte represents the dominant, independent, photosynthetic plant body.
3. The sporophyte bears sporangia which produce spores by meiosis.
4. These spores germinate to form free-living prothallus which represents a gametophyte.
5. Sexual reproduction: syngamy results in the formation of a diploid zygote. Zygote germinates into a diploid sporophyte.
Prothallus:
1. It represents the gametophytic phase.
2. Multicellular, independent, green, photosynthetic thallus.
3. It needs damp and shady places.
4. Bears sex organs, rhizoids and food-laden parenchymatous cells.