Question

Ajay and Vijay are siblings. Ajay can roll his tongue while Vijay cannot. What is the genotype of their parents?

विकल्प

• Both the parents are homozygous dominant.

• Both the parents are homozygous recessive.

• One parent is homozygous dominant, and the other is homozygous recessive.

• Both the parents are heterozygous dominant.

Answer 1

Both the parents are heterozygous dominant.

Explanation:

Ajay’s ability to roll his tongue shows he has at least one dominant allele (R). Vijay lacks the ability to roll his tongue, indicating the presence of two recessive alleles. Vijay’s genotype rr requires both parents to contain at least one recessive allele (r). Therefore, the parents must be heterozygous (Rr).