Question

what does the notation rr mean to geneticists?
○ heterozygous alleles
○ homozygous alleles
○ dominant alleles
○ recessive alleles

Explanation:

In genetics, uppercase letters represent dominant alleles and lowercase letters represent recessive alleles. When an organism has two different alleles (one dominant, one recessive) for a gene, this is defined as heterozygous. The notation Rr has one dominant (R) and one recessive (r) allele, matching this definition. Homozygous refers to two identical alleles (RR or rr), dominant alleles would be represented by uppercase only (R), and recessive alleles by lowercase only (r).

Answer:

heterozygous alleles