The similarities between sickle-cell anaemia and thalassemia are:
(A) Both are autosome linked recessive disease
(B) Both are blood related disorder
(C) Parents of the offsprings are carriers
(D) Both are controlled by same genes
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (B) and (C) only
(A) Both are autosome linked recessive disease Correct. The genes of both disorders lie on autosomes, not on the sex chromosomes. Each shows only when a person has two copies of the faulty allele.
(B) Both are blood related disorder Correct. Both affect the globin chains of haemoglobin in the red blood cells. In sickle-cell anaemia the red cells become sickle-shaped; in thalassemia too few globin chains are made, which causes anaemia.
(C) Parents of the offsprings are carriers Correct. A child gets the disease when both parents are unaffected carriers (heterozygous). Each parent passes one faulty allele to the child.
(D) Both are controlled by same genes Incorrect. Sickle-cell anaemia is controlled by a single pair of alleles, HbA and HbS, of the β-globin gene. α thalassemia is controlled by the genes HBA1 and HBA2 on chromosome 16, and β thalassemia by the gene HBB on chromosome 11. Sickle-cell anaemia makes a wrongly working globin, while thalassemia makes too few globin molecules.
NCERT Extract:
Mendelian Disorders – …
