The strategy of shedding of pollen before maturation of stigma is to prevent self-fertilisation and reduce inbreeding depression. Such mechanisms facilitate cross-pollination and produce genetically better yielding crops.

The exine layer is made up of sporopollenin and intine is made up of cellulose and pectin material.
Exine layer protects the pollen from adverse environmental condition.

The parts of pistil which develop into fruits and seed are ovary and ovules, respectively.

Endosperm is the triploid tissue formed by primary endosperm nucleus containing cell resulting from the fusion of secondary nucleus of one of the male gamete of pollen grain.

One tube cell and two male gametes.

1.Meiosis 2. Mitosis 3.Mitosis

Seed dormancy is the condition of seed when it fails to germinate even eventhough the environmental conditions usually considered favourable for germination of seed are provided.

The two advantages of dormancy of seed are
(i) Dissemination of seeds at desired time
(ii) Adaption of successful seed germination under favourable conditions.

Cross pollination or xenogamy.

1. In a self-pollinated bisexual flower, the anthers and sigma lie close to each other and when the anthers dehisce, the pollen grains fall on the stigma and pollination is effected even in the absence of a pollinator.
2. But in dioecious plants, an agent or a pollinator is necessary.