Question

Although the exact number of genes in human DNA is unknown, scientists estimate the number to be around 20,000 to 25,000.

Answer 1

Answer:

The correct answer is option C, There are several variations, or alleles, of many genes

Explanation:

In a given set of population, and for a given set of genes there can be a single allele or there can be multiple sets of allele. But since any individual can carry only set of chromosome per cell,an individual only carries one or two alleles per gene. But if there are several genes then there would be several variations, or alleles, of many gene

Answer 2

C, you have genes/allels that you got from your parents, but the combination of all your genes together is unique.