Name the following by choosing the correct option:
The type of gene, which in presence of a contrasting allele is not expressed:
Topic: Recessive allele
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(d) Recessive.
A RECESSIVE allele is one that is MASKED when a contrasting dominant allele is present. It expresses itself only when BOTH alleles are recessive (the homozygous recessive state, such as tt).
Why the others are wrong: DOMINANT is the exact opposite — the allele that DOES express itself. HOMOZYGOUS and HETEROZYGOUS are not types of gene at all. They describe the CONDITION of a pair: homozygous means the two alleles are alike (TT or tt), heterozygous that they differ (Tt).
That last point is the real discrimination in this question. Read carefully: it asks for a TYPE OF GENE, so the two words describing pairs can be eliminated at once, leaving only dominant and recessive.
Recessive.