Question

Life cycle in Rockweed of Brown Algae is

• A. Diplo - biontic
• B. Diplontic
• C. Diplo - haplontic
• D. Haplo – diplontic

Hint:

Classify life cycles: haplontic (dominant haploid), diplontic (dominant diploid), haplo-diplontic (alternation of generations).
Remember Fucus as a classic example of diplontic algae.

Answer 1

The Correct Option is B

1. Rockweeds (genus Fucus and similar brown algae) exhibit a diplontic life cycle: the multicellular phase is diploid (the thallus), and the only haploid stages are the gametes. Fertilisation produces a zygote that develops into the diploid thallus.
2. In diplontic life cycles, meiosis produces gametes directly (i.e., gametes are formed by meiosis), and there is no multicellular haploid generation.
3. Therefore the life cycle of rockweed (Fucus) is diplontic. Hence the correct answer is (2) Diplontic.