Biology for IGCSE & O level - Inheritance (Section 4 - No. 1)
If a recessive allele is present in a population, but does not express itself, what must be true about the individual?
The individual is heterozygous.
The individual is homozygous dominant.
The individual has a disease caused by the recessive allele.
The individual's cells don't have genes.
คำอธิบาย
The recessive allele is only expressed in the absence of the dominant allele, therefore it is heterozygous.