Question

Match the diseases of column I with their appropriate match in column II and choose the correct option.

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{1. Sickle cell anaemia}& \text{A. Autosomal dominant}\\ \text{2. Colour blindness}& \text{B. Royal`s disease}\\ \text{3. Haemophilia}& \text{C. Sex-linked recessisve}\\ & \text{D. Qualitative disorder}\\ & \text{E. Quantitative disorder}\end{array}$

• A. 1-B, 2-C, 3-D, 4-A , 5-B
• B. 1-C, 2-A, 3-B, 4-E, 5-D
• C. 1-D, 2-B, 3-A, 4-C, 5-E
• D. 1-D, 2-C, 3-E, 4-B, 5-A

Answer 1

The correct option is D 1-D, 2-C, 3-E, 4-B, 5-A

Sickle cell anaemia is a qualitative disorder. A qualitative disorder is the one which is caused due to deteriorated/defective quality of biological products like protein or hormone while its quantity remains unchanged. In sickle cell anaemia, synthesis of the defected beta globin chain of haemoglobin takes place. There is no change in the quantity of haemoglobin chain synthesis, only the quality of the chain is affected.

Colour blindness is sex-linked recessive disorder. As colour blindness is a X-linked recessive disorder, it will get expressed when genes are altered on both the X chromosomes, allosomes (XX) in females. If out of the two X chromosomes, any one is altered and the other X chromosome is normal, then the females will not have colour blindness, but they could be the carriers and pass the disease to their offspring. While in males, as they have only one X chromosome in their allosomes (XY), alteration in that one X chromosome will cause the disease to get expressed.

It’s believed that Queen Victoria was the carrier of hemophilia and passed the disease onto her children. The family pedigree of Queen Victoria shows a number of haemophilic descendents as she was the carrier. This tagging of royalty terms haemophilia as a Royal's disease.

Quantitative disorder is the type of disorder in which the quantity or the amount of the biological product is affected while the quality remains same. Example: Quantitative platelet disorder in which there is decreased in the number of platelets.