Question

The types of life cycles of I, II and III is

• A. Haplontic life cycle - (I); Alternation of generation cycle - (II); Diplontic life cycle - (III)
• B. Haplontic life cycle - (III); Alternation of generation cycle (II); Diplontic life cycle (I)
• C. Haplontic life cycle- (II); Alternation of generation cycle- (III); Diplontic life cycle- (I)
• D. Haplontic life cycle- (I) ; Alternation of generation cycle- (III); Diplontic life cycle- (II)

Answer 1

The correct option is A Haplontic life cycle - (I); Alternation of generation cycle - (II); Diplontic life cycle - (III)

In the haplontic life cycle, zygotes are the only diploid cell which undergoes meiosis and produces several haploid cell. These cells divide mitotically to form more haploid cells. Two opposite types of gametes (e.g., male and female) from these individuals or cells fuse to become a diploid zygote. Mitosis occurs only in the haploid phase.
Alternation of generation includes the alternation of a sexual phase and an asexual phase in the life cycle. A haploid plant of the gametophyte generation produces gametes by mitosis. Two gametes, either from different organisms of the same species or from the same organism, combine to produce a zygote, which develops into a diploid plant of the sporophyte generation. This sporophyte produces spores by meiosis. which germinate and develop into a gametophyte of the next generation.
In the diplontic life style, gametes are the only haploid cells and mitosis occurs only in the diploid zygote which produces a multicellular diploid individual. Cells from the diploid individuals then undergo meiosis to produce haploid gametes.These haploid gametes do not undergo mitosis, and do not grow into a larger haploid organism. Rather, the haploid gametes fuse and produce the diploid zygote with gametes of the opposite type.

Therefore, the correct answer is option A.