Question

an organism with the genotype dd for a trait is __. select all that apply.
a) recessive
b) dominant
c) heterozygous
d) homozygous

Explanation:

• Recessive: A recessive allele is expressed only in homozygous recessive (e.g., dd). DD has the dominant allele, so not recessive.
• Dominant: The genotype DD has two dominant alleles (assuming D is dominant). Organisms with dominant alleles (homozygous dominant here) express the dominant trait.
• Heterozygous: Heterozygous means having two different alleles (e.g., Dd). DD has two identical alleles, so not heterozygous.
• Homozygous: Homozygous means having two identical alleles. DD has two D alleles, so it is homozygous. Also, since D is dominant (implied by the context of dominant/recessive labeling), DD is homozygous dominant, so it is both dominant (in terms of the trait expressed) and homozygous.

Answer:

B) dominant, D) homozygous