d: gametes
Sperm and ova are both considered gametes. Gametes are specialized reproductive cells that are involved in sexual reproduction. In humans, sperm are the male gametes produced by the testes, while ova (or eggs) are the female gametes produced by the ovaries.
Gametes are unique because they contain half the number of chromosomes compared to other cells in the body. Humans have 46 chromosomes in most of their cells, but gametes only have 23 chromosomes each. This is because during sexual reproduction, when a sperm fertilizes an egg, the resulting zygote will have the full complement of 46 chromosomes, with half coming from each parent.
The production of gametes is part of the process of meiosis, which is a specialized type of cell division that reduces the chromosome number by half. This ensures that when gametes combine during fertilization, the resulting zygote will have the correct number of chromosomes for normal development.
So, in summary, sperm and ova are both gametes because they are specialized reproductive cells that contain