AP BIOLOGY

Detailed explanation-1: -The haploid sperm and haploid egg combine to form a diploid zygote, the process being called syngamy, while the other sperm and the two haploid polar nuclei of the large central cell of the megagametophyte form a triploid nucleus (triple fusion). Some plants may form polyploid nuclei.

Detailed explanation-2: -Pollen grains are haploid, sperm-producing structures and therefore represent the male gametophyte (or microgametophyte). Embryo sacs are haploid, egg-producing structures which constitute the female gametophyte (or megagametophyte). Figure 1.

Detailed explanation-3: -Pollen grains contain the highly reduced haploid microgametophyte generation in seed plants that establishes the male germline during sexual reproduction.

Detailed explanation-4: -The haploid gametophyte produces the gametes, or sperm and egg, by mitosis. Remember, gametes are haploid, having one set of chromosomes. Then, the sperm fertilizes the egg, producing a diploid zygote that develops into the sporophyte, which of course, is diploid.

Detailed explanation-5: -In short a gamete is an egg cell (female gamete) or a sperm (male gamete). In animals, ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism.