Answer: a). AA
Explanation: Every trait is controlled by at least a pair of gene. Genes have different forms known as alleles. Alleles can be dominant or recessive. A dominant allele expresses itself in the presence of a recessive allele and masks the effect of a recessive allele. A recessive allele cannot express itself in the presence of a dominant allele and it's effect is masked by a dominant allele. Dominant alleles are usually written in upper cases such as A, T, while recessive alleles are usually written in lower cases such as a, t. The two alleles that determines a trait is called a genotype. A genotype can be homozygous if the two alleles are identical such as in AA or aa
and can be heterozygous if the two alleles are not identical such as in Aa, Tt.
As a source of Cellular respiration .......
Schizocoely is a process by which some animal embryos develop while splitting the mesodermal embryonic tissue. On the other hand, <span> enterocoelous was formed </span><span>in which the coelom forms from pouches "pinched" off of the digestive tract.</span>
. I think that bivalves have evolved to have smaller head regions because they have also evolved to have bigger shells or valves than cephalopod