What term refers to a reproductive cell of the body?

The term that refers to a reproductive cell of the body is a germ cell. Germ cells are specialized cells that give rise to gametes, which are the reproductive cells involved in sexual reproduction—sperm in males and eggs in females. These cells undergo a specific process called meiosis, which reduces the chromosome number by half, allowing for the formation of haploid gametes that can combine during fertilization to form a diploid zygote.

Stem cells, on the other hand, are undifferentiated cells capable of giving rise to various cell types but are not themselves reproductive cells. Somatic cells refer to all body cells that are not involved in reproduction, containing the full set of chromosomes, while the term "sexual cell" is not a standard term used in biology. Thus, germ cells are precisely defined as the cells that participate directly in reproduction, making this term the correct choice.