AP BIOLOGY

Detailed explanation-1: -Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells).

Detailed explanation-2: -The sperm cells of a flowering plant are contained in pollen grains. Pollination occurs when pollen grains are transported from anthers to stigmas.

Detailed explanation-3: -There is no sperm present in a pollen grain. A pollen grain is a tiny male plant, a male gametophyte (gamete-forming plant). He is a multicellular organism (usually two cells in flowering plants, but more in the case of gymnosperm pollen) capable of producing sperm if he gets an opportunity.

Detailed explanation-4: -Each pollen grain is a single cell containing two male gametes. Once mature, the anther splits open and pollen is released. Both male gametes are involved in fertilisation, resulting in formation of a zygote and an endosperm.

Detailed explanation-5: -pollen, a mass of microspores in a seed plant appearing usually as a fine dust. Each pollen grain is a minute body, of varying shape and structure, formed in the male structures of seed-bearing plants and transported by various means (wind, water, insects, etc.) to the female structures, where fertilization occurs.