Question

When the gametophyte is not formed by spores but by any other part of sporophyte, it is known as
A. Multispory
B. Polysopry
C. Apospory
D. Germination

Answer 1

In plants, the haploid phase is called gametophyte and diploid phase is called sporophyte. When a saprophytic cell undergoes meiosis, haploid spores are produced which later divide mitotically to form a multicellular gametophyte.

Complete Answer:
- The land plant spores that develop into male gametophytes are called microspores. The plant spores that develop into female gametes are called megaspores. Each mother cell of a microspore undergoes mitotic cell division that produces haploid microspore or pollen grains. They are arranged in tetrads.
- In Drosera, all the four spores are not separated and they form a compound pollen grain. In the plants that belong to family Cypreaceae. Her, out of four spores, three spores degenerate and only one spore is formed.
- In some cases, one microspore mother cell produces more than four pollen. This phenomenon is called polyspory. Eg: Cuscuta
- The development of a gametophyte is from nonreproductive cells or vegetative cells without spores and meiosis is called apospory.
- The beginning of development of a spore or a seed into seedling is called germination in plants. Eg: formation of sporeling from a spore and formation of seedling from seed sprouting.

Therefore the correct answer is (C) Apospory.

Note: Apospory involves the development of diploid(2n) gametophyte from vegetative or non-reproductive cells whereas in apogamy there is the development of haploid(1n) sporophytes without gametes and syngamy from vegetative cells of the gametophyte.