Home › NEET UG › Biology › Principles Of Inheritance › If skin colour is determined by three genes A, B…
If skin colour is determined by three genes A, B and C with additive dominant alleles, two parents of genotype AaBbCc each produce a child. What is the probability that the child has the darkest possible phenotype (AABBCC)?
AOne in eight
BOne in sixteen
COne in thirty-two
DOne in sixty-four
Answer & Solution
Correct answer: D. One in sixty-four
For each gene, the probability of AA from Aa x Aa is one quarter. For three independently assorting genes, the joint probability is (1/4) x (1/4) x (1/4) = 1/64. Only this genotype gives the darkest additive phenotype.
Related questions
How many chromosomes are there in a normal human cell?The gain or loss of a single chromosome is called:Turner's syndrome in human females results from the loss of:Down's syndrome results from an extra copy of chromosome:In sickle-cell anaemia the red cell changes from a biconcave disc to a:A heterozygous female for haemophilia is called a:Morgan carried out his crosses using:Who proposed the chromosomal theory of inheritance?