The biological species concept states that species is a........of organisms?

Question

in the law of dominance, one allele is expressed while the other is masked. In......................both alleles are expressed in a heterozgous

Answer 1

for your first one:

species are groups of interbreeding natural populations (or organisms that are reproductively isolated from other such groups.

for your second one, Codominance has both alleles expressed in heterozygous individuals