How many meiotic divisions are required to produce 100 seeds in most of angiosperms?

Solution:

To produce 100 seeds, 100 ovules must be fertilized by 100 pollen grains.

1. For ovule formation (female gametophyte): In angiosperms, one megaspore mother cell (MMC) undergoes one meiotic division to produce four megaspores. Out of these four, three usually degenerate, and one functional megaspore develops into the embryo sac (which contains the egg cell). Therefore, 1 meiotic division is required for the formation of 1 ovule. To produce 100 ovules, 100 meiotic divisions are needed.

2. For pollen grain formation (male gametophyte): One microspore mother cell (PMC) undergoes one meiotic division to produce four microspores (pollen grains). Therefore, to produce 100 pollen grains, 100/4 = 25 meiotic divisions are needed.

Total meiotic divisions required = Meiotic divisions for ovules + Meiotic divisions for pollen grains

Total = 100 + 25 = 125 meiotic divisions.