Question

A recessive allele is expressed in _________.

• A. heterozygous condition only
• B. homozygous condition only
• C. $F_3$ generation only
• D. both homozygous and heterozygous conditions

Answer 1

The correct option is B homozygous condition only

The factor of an allelic or allelomorphic pair that is unable to express its effect in the presence of its contrasting factor in a heterozygote is called recessive factor or allele, e.g, the allele 't' in hybrid tall pea plant Tt. The effect of recessive factor becomes known only when it is present in the pure or homozygous state, e.g, tt in dwarf pea plants.