Lecture 14 Vitamin A - MC

Question 1

What is the primary function of Vitamin A that was originally discovered?
A) It helps to build strong bones.
B) It prevents night blindness.
C) It enhances muscle growth.
D) It boosts the immune system.

Answer 1

B

Question 2

Vitamin A is described as a generic descriptor for compounds that exhibit the biological activity of which substance?
A) Carotenoids
B) Retinol
C) Lipids
D) Proteins

Answer 2

B

Question 3

Which of the following is NOT a form of retinoid?
A) Retinol
B) Retinal
C) Lycopene
D) Retinoic acid

Answer 3

C

Question 4

*Which characteristic describes Vitamin A’s solubility?
A) Water-soluble
B) Fat-soluble
C) Alcohol-soluble
D) Insoluble

Answer 4

B

Question 5

What is the role of retinoic acid in the cell?
A) It acts as an enzyme in metabolic reactions.
B) It stores energy for cell use.
C) It acts in the nucleus of the cell to affect gene expression.
D) It assists in cell membrane formation.

Answer 5

C

Question 6

*In the vision process, what happens when light hits the eye?
A) Opsin and cis-retinal combine to form rhodopsin.
B) Cis-retinal converts into trans-retinal and separates from opsin.
C) Trans-retinal becomes cis-retinal and binds to opsin to reform rhodopsin.
D) Both B and C are correct.

Answer 6

D

Question 7

*Why is Vitamin A necessary for vision in low light conditions?
A) It increases the production of white blood cells.
B) It enables the rhodopsin cycle to be more active as it gets dark.
C) It prevents the retina from overheating.
D) It increases the optical clarity of the cornea.

Answer 7

B

Question 8

*What occurs if there is a deficiency of retinal in the eye?
A) The eye can adapt by using other forms of vitamin A.
B) The rhodopsin cycle can still occur, but less effectively.
C) The process to convert cis-retinal to trans-retinal and back will not occur.
D) The eye’s color perception is enhanced.

Answer 8

C