Answer:
b. form of a gene
Explanation:
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. Genotypes are described as homozygous if there are two identical alleles at a particular locus and as heterozygous if the two alleles differ.
Answer:
The crust is not the thickest layer of earth
:)
They occur in germ cell DNA, which are the cells that create sperm or Ova. For every 85 million nucleotides assembled in DNA during human sperm or Ova production, One will be a mutation