Biology for IGCSE & O level - Inheritance (Section 3 - No. 9)
What does the term 'recessive' refer to in genetics?
An allele that is always expressed.
An allele that is only expressed when homozygous.
An allele that is dominant.
The physical characteristics of an organism.
คำอธิบาย
A recessive allele is only expressed in the phenotype when the individual is homozygous for that allele.