Question

Recessive gene can express itself only in__________________

• A. Homozygous condition
• B. Heterozygous condition
• C. All of the above
• D. None of these

Answer 1

The correct option is A Homozygous condition

• A recessive gene can express only in homozygous condition.

Dominant alleles can express in both homozygous and heterozygous conditions.

• For example, TT and Tt give a tall phenotype whereas tt alone can give dwarf phenotype.
• When a trait is recessive, an individual must have two copies of a recessive allele to express the trait. Recessive alleles are denoted by a lowercase letter (a versus A).
• Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait.