Which of the following genotypes could be described as homozygous dominant? a. bb b. aa c. xx d. tt

The correct answer is- B) AA.

Dominant allele is the one that masks the expression of recessive allele and is depicted by capital letter. Homozygous dominant genotype means both the alleles ( alternative form of a gene) are same.

Out of the given options, option B) AA shows that both the alleles are same and are dominant.

Thus, B) is the right answer.

not sure if this is what you'r looking for eubacteria and archaebacteria