Question

In angiosperms, microsporogenesis, and megasporogenesis
(a) Occur in ovule
(b) Occur in anther
(c) Form gametes without further divisions
(d) Involve meiosis

Answer 1

Hint: In both microsporogenesis and megasporogenesis cells are formed from diploid cells where the chromosome number is reduced to half.

Complete step by step answer:
The formation of microspores is called micro- organisms and embryo sac formation is called megasporogenesis.
Cells in the primary sporogenous layer (PSL) of another undergo mitosis and form a mass of diploid sporogenous tissue which then forms microspore mother cells (MMC). They further divide by meiosis to form haploid microspores of pollen grains.
Nutritive cellular mass is an ovary called the nucleus. Nucellus even at an early stage, one cell becomes evident in the Nucellus which is known as megaspore mother cell (MMC) which tender go meiosis forms four haploid megaspore cells, out of four cells, three cells degenerate and one cell becomes functional and develops into embryogenesis.
So, the correct answer is ‘involve meiosis’

Additional information: Microspore mother cell also called pollen mother cell (PMM).
At maturity pollen grains are either 2-celled (70%) or 3-celled (30%).
2 celled pollen grains have longer vegetative cells and smaller generative cells.
3 celled pollen grains have longer vegetative cells and 2 sperms arranged together as a Male germ unit. The type of female gametophytes is distinguished by the number of megaspores involved in the formation of the embryo sac.
- Monosporic: 1 gametocyte
- Diasporic: 2 gametophyte
- Tetrasporic: 4 gametophyte

Note: Pollen mother cell and Megaspore Mother Cells are diploid pollen grains (microspores) and embryo sac (megaspores) are haploid. Meiosis is also called reduction division in which a reduction in the number of chromosomes occurs at meiosis-I. meiosis-II is the same as mitosis.