The pigment that is responsible for the color of the iris in the eye is: MCQ with Answer and Explanation

The pigment that is responsible for the color of the iris in the eye is:
A. Carotene
B. Melanin
C. Hemoglobin
D. Rhodopsin
Answer: Option B
Solution (By JKExamLibrary)
Melanin pigment in the iris determines eye color. High melanin: brown; low melanin: blue/green. Hemoglobin is in blood, carotene in plants, rhodopsin in retina.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
In plant physiology, the 'Osmotic pressure' is the pressure that must be applied to a solution to prevent the inward flow of water across a semipermeable membrane. It is directly proportional to the:
A. Size of the solute molecules
B. Temperature only
C. Volume of the solution
D. Concentration of solute particles

Correct Answer: Option D


Explanation:
Osmotic pressure (OP) is a colligative property of a solution, meaning it depends on the number of solute particles dissolved in a given volume of solvent, not on the nature or size of the particles. It is defined as the hydrostatic pressure that must be applied to a solution to prevent the net flow of water (osmosis) into the solution across a semipermeable membrane. According to the van't Hoff equation, osmotic pressure is directly proportional to the molar concentration of solute particles and the absolute temperature. The more concentrated the solution, the higher its osmotic pressure.

This question belongs to: Science Biology
Question #2
Consider statements about animal husbandry: 1. Silkworms feed on mulberry leaves. 2. Honeybees communicate through the waggle dance. 3. Fish farming is called sericulture. Which are correct?
A. 1, 2 and 3
B. 1 and 3 only
C. 1 and 2 only
D. 2 and 3 only

Correct Answer: Option C


Explanation:
The domesticated silkworm, Bombyx mori, is a monophagous insect that feeds exclusively on the leaves of the mulberry plant (Morus alba). Honeybees perform a 'waggle dance' on the honeycomb to communicate the direction and distance of food sources to other worker bees. Fish farming is called pisciculture or aquaculture; sericulture specifically refers to the rearing of silkworms for silk production. Thus, statements 1 and 2 are correct.

This question belongs to: Science Biology
Question #3
Consider statements about human diseases: 1. Typhoid is caused by Salmonella typhi. 2. Malaria is caused by a virus. 3. Ringworm is a fungal infection. Which are correct?
A. 1 and 3 only
B. 2 and 3 only
C. 1, 2 and 3
D. 1 and 2 only

Correct Answer: Option A


Explanation:
Typhoid fever is a bacterial disease caused by Salmonella enterica serotype Typhi. Ringworm is a superficial fungal infection caused by dermatophytes like Microsporum and Trichophyton. Malaria is not caused by a virus; it is caused by a protozoan parasite of the genus Plasmodium. Therefore, statements 1 and 3 are correct, while 2 is false.

This question belongs to: Science Biology