Question

The main evolutionary feature of alternation of generations from algae to modern tracheophytes is

• A. Elimination of sporophyte
• B. Gradual elaboration of sporophyte
• C. Gradual elaboration of gametophyte
• D. Both B and C

Answer 1

Answer: (B)

Gradual elaboration of sporophyte

The evolution of land plants has brought in wide levels of complexity from algal forms to bryophytes, to gymnosperms and angiosperms. However, in the process of evolution, the development of sex preceded the alternation of generations and the gametophyte generation is considered to be older than the sporophyte generation and in higher plants the sporophytic generation has become the dominant stage. The pattern in plant evolution has seen a shift from homomorphy to heteromorphy where the algal ancestors were haplobiontic during their life cycle while the land plants show a predominant diploid phase in their life cycle.

Hence the correct option is B.