Identify the incorrect statements from the following:
A. Phenylketonuria is an autosomal dominant trait.
B. Haemophilia is a sex linked recessive disease.
C. Thalassemia is an autosomal linked recessive blood disease.
D. Colour blindness is an autosomal linked recessive disorder.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A and D only
A. Phenylketonuria is an autosomal dominant trait. — False. Phenylketonuria is an autosomal recessive disorder.
B. Haemophilia is a sex linked recessive disease. — True.
C. Thalassemia is an autosomal linked recessive blood disease. — True.
D. Colour blindness is an autosomal linked recessive disorder. — False. Colour blindness is sex-linked (X chromosome) recessive.
NCERT Extract:
Mendelian Disorders – “… Colour Blidness : It is a sex-linked recessive disorder due to defect in either red or green cone of eye resulting in failure to discriminate between red and green colour.”
Mendelian Disorders – “… Haemophilia : This sex linked recessive disease, which shows its transmission from unaffected carrier female to some of the male progeny has been widely studied.”
Mendelian Disorders – “… Phenylketonuria : This inborn error of metabolism is also inherited as the autosomal recessive trait.”
Mendelian Disorders – “… Thalassemia : This is also an autosome-linked recessive blood disease transmitted from parents to the offspring when both the partners are unaffected carrier for the gene (or heterozygous).”