Final answer:
The gene pool of a population consists of all the genes and their alleles in that population. An organism's phenotype is determined by the interaction of alleles, which are different versions of a gene.
Step-by-step explanation:
The entire collection of genes and their alleles is known as the gene pool of a population. The gene pool consists of all the genes of all the members of the population, including all the different alleles for each gene that exist in the population. These alleles can interact to express physical characteristics, which are referred to as an organism's phenotype.