Why is the structure of a
nucleosome so important?

Nucleosomes are the basic packing unit of DNA built from histone proteins around which DNA is coiled. They serve as a scaffold for the formation of higher-order chromatin structure as well as for a layer of regulatory control of gene expression.

Explanation:

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.