DENDROLOGY

Detailed explanation-1: -In cross pollinating plants, pollen grains fall and germinate on the stigma. This process is called pollination. The pollen tubes carrying the male gametes reach the ovule and deposit them near the egg.

Detailed explanation-2: -Pollination refers to the landing and subsequent germination of the pollen on the stigma. Hence it involves an interaction between the gametophytic generation of the male (the pollen) and the sporophytic generation of the female (the stigmatic surface of the carpel).

Detailed explanation-3: -Due to the spatial separation between male and female organs, pollen grains from the anther of most flowering plants are transported by wind or animals and deposited onto the receptive surface of the stigma of a different plant [9], [10].