Which of the following has one set of homologues?

The correct response is that gametes have one set of homologues. Gametes, which are the reproductive cells (sperm and eggs in animals), are produced through the process of meiosis. Unlike diploid cells, which contain two sets of chromosomes (one from each parent), gametes are haploid, meaning they contain only one complete set of chromosomes. This is crucial for sexual reproduction because when two gametes unite during fertilization, they restore the diploid state in the resulting zygote.

In contrast, somatic cells contain two sets of homologous chromosomes, one set inherited from each parent, and are classified as diploid cells. Neurons, being a type of somatic cell, also have two sets of homologous chromosomes. Therefore, gametes are unique in that they only have one set of homologues, allowing them to participate in genetic recombination and variation during reproduction.