Different _ of an element have different number of neutrons

explanation:

the sequence of amino acids in a protein determines its function. the dna sequence of a gene determines the amino acid sequence of the resulting protein. thus, any changes in dna sequence can result in changes in protein function. this is called a mutation.

hope it mark me as brainlieast.

i think it is dna, i'm not totally sure but i think it might be.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.