Q. I. Enborn error of metabolism II. Homozygous recessive autosomal alleles on chromosomes 12 causes absence of the specific enzyme III. A specific amino acid do not changes into tyrosine IV. Accumulation of phenylpyruvic acid and other derivatives leading to mental retardation The above facts refer to
A) Muscular dystrophy
B) Phenylketonuria
C) Turner’s syndrome
D) Down’s syndrome
Explanation
Phenylketonuria (chromosomes 12) (i) It is inborn error of metabolism and is inherited as autosomal recessive trait (ii) The affected individual lacks an enzyme called phenylalanine hydroxylase that converts the amino acid phenylalanine into tyrosine in liver. (iii) Phenylalanine is accumulated and gets converted into phenylpyruvic acid and other derivatives. This effects the brain, resulting in mental disorder
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.