What is the term used to describe reproductive cells like sperm and egg?

The term that describes reproductive cells such as sperm and egg is "gamete." Gametes are specialized cells that carry half of the genetic information necessary for reproduction. In humans and many other organisms, the male gamete is the sperm, while the female gamete is the egg (or ovum). During fertilization, the genetic material from both gametes combines to form a new organism with a unique genetic identity.

The other terms relate to genetics but do not specifically refer to reproductive cells. An allele refers to a variation of a gene, which contributes to the genetic diversity within a population. Chromosomes are structures within cells that contain DNA and carry genetic information; each organism has a specific number of chromosomes that house multiple genes, but they are not reproductive cells themselves. A phenotype is the observable physical or biochemical characteristics of an organism, determined by both genetic makeup and environmental influences, rather than being a type of reproductive cell.