AP BIOLOGY

Detailed explanation-1: -Fungal spores and pollens can be dispersed in a number of ways: by animals and insects; by water; by wind or by rain. This paper concentrates on the effects of wind on the dispersal of spores and pollen grains and the effects of rain on spore dispersal.

Detailed explanation-2: -Pollen grains are smooth, small and light, which makes it easier for the wind to carry the pollen grains to long distances.

Detailed explanation-3: -A mature ovule consists of a food tissue covered by one or two future seed coats, known as integuments. A small opening (the micropyle) in the integuments permits the pollen tube to enter and discharge its sperm nuclei into the embryo sac, a large oval cell in which fertilization and development occur.

Detailed explanation-4: -The anther usually contains four pollen sacs which are responsible for producing pollen grains. Each pollen grain is a single cell containing two male gametes. Once mature, the anther splits open and pollen is released.