Question

Identify the correct statement(s) out of the following
a. Deficiency of vitamin A causes xerophthalmia.
b. The function of vitamin C is maintenance of redox potentials of cells.
c. Vitamin B${}_{12}$ contain ionone ring.
d. Folic acid (vitamin B${}_9$) consists of corrin ring.

• A. a only
• B. a and b
• C. a, b and c
• D. all

Answer 1

Answer: (B)

a and b

Option (B) is correct.
A. Deficiency of vitamin $A$ causes xerophthalmia. It is a condition in which an eye becomes abnormally dry because it can't maintain an adequate layer of tears to coat its surface.
B. The function of vitamin $C$ is maintenance of redox potentials of cells important for defence against infections such as common colds. It also acts as an inhibitor of histamine, a compound that is released during allergic reactions. As a powerful antioxidant it can neutralize harmful free radicals and it aids in neutralizing pollutants and toxins.
C. Vitamin $A$ contain ionone ring. All forms of vitamin $A$ have acbeta -ionone ring to which an isoprenoid chain is attached, called a retinyl group.
D. Folic acid (vitamin B${}_{12}$) consists of corrin ring. It contains a cobalt ion as part of the porphyrin-like corrin ring.