Class 12 NEET Biology Principles of Inheritance and Variation Questions Part 2

This chart shows inheritance of an autosomal recessive trait like phenylketonuria. An autosomal recessive trait may skip a generation. It appears in case of marriage between two heterozygous individuals (Aa ×Aa=3Aa+1 aa), a recessive individual with hybrid (Aa×aa=2Aa+2aa) and two recessive × aa = all aa ). Phenylketonuria is an inborn, autosomal, recessive metabolic disorder in which homozygous recessive individual lacks the enzyme phenylalanine hydroxylase. The heterozygous individuals are normal but carriers.