WAEC Biology 2021 Papers

Concept:Smooth eyebrows are recessive, so a person with smooth eyebrows must have the genotype $bb$.Explanation:The mother has smooth eyebrows, so her genotype is $bb$.The student also has smooth eyebrows, so the student's genotype is also $bb$.The student inherits one allele from each parent. Therefore, the student must receive a $b$ allele from the mother and a $b$ allele from the father.Since the father has pointed eyebrows, he must carry the dominant allele $B$.To pass a $b$ allele to the student, the father must also carry a recessive $b$ allele.Thus, the father's genotype must be $Bb$, not $BB$ or $bb$.Answer:The father's genotype is $Bb$ (heterozygous pointed eyebrows).