Question

Choose the correct statements:
Statements:
A. In sickle cell anemia, a valine is substituted for the glutamic acid at a location on the surface of the protein near the oxygen-binding site.
B. The red blood cells of people who are homozygous for the sickle cell allele collapse into sickled shape when the oxygen level in the blood is low.
C. Individuals who are heterozygous for the recessive valine-specifying allele are said to possess the sickle cell trait.
Choose the correct answer from the options given below:

• A. (A) and (B) only
• B. (B) and (C) only
• C. (A), (B), (C)
• D. (A) and (C) only

Hint:

Sickle cell anemia is a result of a single nucleotide mutation, leading to a missense mutation in the HBB gene.

Answer 1

The Correct Option is C

The following points describe the characteristics and genetic basis of sickle cell anemia, red blood cells, and the sickle cell trait.

• (A): Sickle cell anemia involves the substitution of valine for glutamic acid at position 6 in the beta chain of hemoglobin, leading to the formation of abnormal hemoglobin (HbS).
• (B): Individuals homozygous for the sickle cell allele (HbS/HbS) have red blood cells that deform into a sickled shape under low oxygen, causing blood vessel blockages and impaired oxygen delivery.
• (C): Heterozygous individuals (HbA/HbS) carry the sickle cell trait. They usually do not display severe symptoms but may experience mild symptoms in extreme conditions.