AP BIOLOGY

Detailed explanation-1: -It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This can make endosperm a source of nutrition in animal diet.

Detailed explanation-2: -The triploid nucleus in double fertilization develops into an endosperm which provides nutrition to the growing embryo.

Detailed explanation-3: -In most flowering plants, the central cell contains two haploid nuclei, which fuse prior to or at fertilization. The fusion of this homodiploid nucleus with the sperm nucleus results in a triploid primary endosperm nucleus with two maternal and one paternal genome complements (2m:1p).

Detailed explanation-4: -The zygote now has a full complement of chromosomes (i.e., it is diploid), and the endosperm nucleus has three chromosomes (triploid). The endosperm nucleus divides mitotically to form the endosperm of the seed, which is a food-storage tissue utilized by the developing embryo and the subsequent germinating seed.

Detailed explanation-5: -Of the two sperm cells, one sperm fertilizes the egg cell, forming a diploid zygote; the other sperm fuses with the two polar nuclei, forming a triploid cell that develops into the endosperm.