To protect an endangered species, a group of biologists have decided to store the genes of the species. they think that this will prevent the extinction of the species. which method are these biologists adopting?

The method store genes of endangered species is the genome conservation.

A set of DNA, including all of its genes makes up genome of an organisms. Each genome contains all of the information needed to build and maintain that organism. The population of endangered species is small which suffer from reduced genetic diversity through inbreeding. In conservation genomics, the study of genetic diversity in all genes is carried out for better understand their implications to ecology, health, and disease.

sex cells are usually half's then they find another half and make a fertilize egg

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.