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

All the given statements correctly describe the characteristics and genetic basis of Sickle cell anemia, Red blood cells of people and Sickle cell trait.

• (A): In sickle cell anemia, the substitution of valine for glutamic acid occurs in the beta chain of hemoglobin at position 6, leading to abnormal hemoglobin (HbS) formation.
• (B): Individuals homozygous for the sickle cell allele (HbS/HbS) have red blood cells that collapse into a sickled shape under low oxygen conditions, causing blockages in blood vessels and reduced oxygen delivery.
• (C): Heterozygous individuals (HbA/HbS) are said to have the sickle cell trait. They generally do not exhibit severe symptoms but can experience mild symptoms under extreme conditions.