The Presence of a Recessive Gene Can Be Detected (Seen)

Question

The presence of a recessive gene can be detected (seen) only if the individual is
A) homozygous recessive.
B) heterozygous dominant.
C) heterozygous recessive.
D) homozygous dominant.
E) epistatic recessive.

Accepted Answer

A recessive gene is only expressed (seen) if an individual has two copies of the recessive allele, which means the individual has to be homozygous recessive (having two copies of the recessive allele). Heterozygous dominant individuals would have one copy of the recessive allele but would not express the trait. Heterozygous recessive individuals would also have one copy of the recessive allele but would only express the trait if paired with another heterozygous recessive or homozygous recessive individual. Homozygous dominant individuals would not carry the recessive allele and would not express the trait. Epistatic recessive is not a relevant term in this context.