Question

The main evolutionary feature of alternation of generation from algae to modern tracheophyte is
(a) Elimination of sporophyte
(b) Gradual elaboration of the sporophyte
(c) Gradual elaboration of gametophyte
(d) Both b and c

Answer 1

One of the most important of sexual reproduction is evolution and for an organism, to evolve there should be development or changes in the gametes.

Complete answer:
In algae and higher plants, they show a type of life cycle that contains both haploid and diploid sexual stages. This is called alternation of generations also called metagenesis. The haploid gametophyte is formed from haploid spores and gametes are produced at maturity which fuse to form the diploid zygote. The sporophyte is formed from the diploid zygote. The cycle from sporophyte to gametophyte and from gametophyte to sporophyte is seen in algae and other higher plants that undergo sexual reproduction. This is considered a main evolutionary feature.

Additional Information: - Gametophyte and sporophyte relation varies among different plant groups. sporophyte and gametophyte are different organisms that are independent in algae that show alternation of generation. They are not similar in appearance.
- In bryophytes such as liverworts, hornworts, and mosses, the well-developed sporophyte is seen. It is well developed than the gametophyte
- Alternation of generation is seen in plants with diplohaplontic, haplodiplontic, diplobiontic, and dibiontic life cycles.
- In animals alternation of generation is absent. It has only one stage i.e, the diplontic stage
- Haplontic life cycle refers to the organisms that have only haploid multicellular stage
So, the correct answer is 'Both b and c'

Note: -Along with algae and other higher plants, alternation of generation is exhibited by some organisms classified in the clade Rhizaria.
-Mycelium in fungi are typically haploid but when mating of different mycelia takes place it results in two ball-shaped multinucleate cells joined by a mating bridge resulting in heterokaryon.