What are the different versions or variety of a gene called

An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.

Explanation:

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse