Upon fertilization, two haploid gametes become one diploid zygote. Updated November 06, Share Flipboard Email. Some male and female gametes are of similar size and shape, while others are vastly different.
A sperm cell may either have an X or Y sex chromosome, but an egg cell can only have an X chromosome. Share Flipboard Email. Updated November 20,
Ginzburg, A. In coelenterates, flat-worms, and sea urchins, the pronuclei fuse into a single zygote nucleus. The head steadily swells and is transformed into a bladder-like male pronucleus, which appears to be led by the moving sperm-aster.
Show sources information. Hyphae are structures that grow out of the ascogonium; the nuclei of the dikaryons divide synchronously within the hyphae. The nuclei only come together in pairs, forming dikaryons. The term reproduction may refer to this power of self-duplication of a single cell or a multicellular animal or plant organism.
Gametes differ widely in males versus females for a given organism. Regina Bailey. Key Takeaways: Sex Cells Sexual reproduction occurs through the union of sex cells, or gametes.