gamete

Cell that functions in sexual reproduction by merging with another gamete to form a zygote. Examples of gametes include sperm and egg cells. In most organisms, the gametes are haploid (they contain half the number of chromosomes of the parent), owing to reduction division or meiosis.

In higher organisms, gametes are of two distinct types: large immobile ones known as eggs or egg cells (see ovum) and small ones known as sperm. They come together at fertilization. In some lower organisms the gametes are all the same, or they may belong to different mating strains but have no obvious differences in size or appearance.