Q. Haplontic life cycle generally occurs in
Solution:
Based on the predominant stage found, the life cycles of the lower plants can be divided into three types:
- In Haplontic life cycle, the major phase is gametophytic and haploid. The gametes fuse to form diploid zygote, which undergoes meiosis to revert the haploid phase. The meiosis is called zygotic meiosis or terminal meiosis. This is common in most algae (except a few like Fucus).
- In Diplontic life cycle, the major phase is sporophytic and diploid. The gametes are formed by meiotic division and represents the gametophytic generation. Gametes fuse to revert the sporophytic condition. The meiosis is called gametic meiosis or initial meiosis. This is seen in Gymnosperms and Angiosperms.
- Haplo-diplontic life cycle is seen in Bryophyta, where the gametophyte is predominant and gametic fusion results into the formation of sporophyte. Spores of the sporophyte are formed by meiosis. The meiosis is called sporic meiosis or intermediate meiosis.
- In Haplontic life cycle, the major phase is gametophytic and haploid. The gametes fuse to form diploid zygote, which undergoes meiosis to revert the haploid phase. The meiosis is called zygotic meiosis or terminal meiosis. This is common in most algae (except a few like Fucus).
- In Diplontic life cycle, the major phase is sporophytic and diploid. The gametes are formed by meiotic division and represents the gametophytic generation. Gametes fuse to revert the sporophytic condition. The meiosis is called gametic meiosis or initial meiosis. This is seen in Gymnosperms and Angiosperms.
- Haplo-diplontic life cycle is seen in Bryophyta, where the gametophyte is predominant and gametic fusion results into the formation of sporophyte. Spores of the sporophyte are formed by meiosis. The meiosis is called sporic meiosis or intermediate meiosis.