Give a brief account on the phases of the life cycle of an angiosperm plant.

Explanation

In the life cycle of an angiospermic plant, two phases occur alternately. They are
A) Sporophytic phase : It is diploid (2n) and dominant phase of the life cycle. It is developed from the zygote. Reproductive organs develop on this plant.
B) Gametophytic phase : It is haploid (n). It is derived from a spore which is a product of meiotic division of spore mother cell. In angiosperms, microspore mother cells and megaspore mother cells are present. Microspore mother cells develop in an anther while megaspore mother cells develop from the nucleus of the ovule. Each of these cells in turn gives microspores and megaspores after meiotic division. These micro and megaspores develop into male and female gametophytes respectively. The male gametophyte give male gametes & the female gametophyte forms the egg cell. Male and female gametes (Egg) fuse to form a diploid zygote which develops into embryo in the seed. When the seed germinates, the embryo develops into sporophytic plant.