Question

Zygotic meiosis occurs in
a) Gymnosperms
b) Ferns
c) Moss
d) Algae

Answer 1

Hint: It occurs in simple, non-flowering aquatic plants that exist in generally single-celled forms. These plants contain chlorophyll for photosynthesis but lack advanced plant body configuration like most of the other flowering plants.


Complete answer:
In zygotic meiosis, a zygote divides meiotically immediately after the fusion of two cell nuclei and thus haploid cells are produced that either form larger individuals by dividing mitotically or form more haploid cells. This type of life cycle is shown by many algae like Spirogyra, Volvox, and is called a haplontic life cycle.

Additional information:
>In this life cycle, the sporophytic generation is represented by only one-celled zygotes and there are no free-living sporophytes. In the plants having such a type of life cycle, the dominant and photosynthetic phase is the free-living gametophyte and thus the organisms are haploid. This type of life cycle is also exhibited by some species of Chlamydomonas.
>All the seed-bearing plants exhibit a life cycle in which diploid sporophyte is the dominant and independent phase and capable of photosynthesis. This life cycle is termed as a Diplontic life cycle.


Note: In plants, both haploid and diploid cells can divide by mitosis and due to this ability, different types of plant bodies i.e. haploid and diploid are formed. The haploid one produces gametes by mitosis while in diploid one the gametes are produced by meiosis. A haploid plant body represents a gametophyte while the diploid one is called the sporophyte. Due to the presence of alternative haploid and diploid phases in the plant life cycle, it is known as alternation of generation.