Principles of Inheritance and Variation Question 158
158. Study the pedigree chart given below:
What does it show?
[2009]
(a) Inheritance of a condition like phenylketonuria as an autosomal recessive trait
(b) The pedigree chart is wrong as this is not possible
(c) Inheritance of a recessive sex - linked disease like haemophilia
(d) Inheritance of a sex -linked inborn error of metabolism like phenylketonuria
Show Answer
Answer : a
Hints & Solution
(a) The chart shows the inheritance of a condition like phenylketonuria as an autosomal recessive trait. Parents need to be heterozygous as two of their children are known to be sufferer of the disease. It cannot be recessive sex linked inheritance because then the male parent would also be sufferer.
