Question

Given below are two statements
Statement I: Rods of fish eye are sensitive to lowlight levels and provide low resolution.
Statement II: Cones of fish eye are less sensitive to light and require brighter light.
In light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Hint:

Remember:
- Rods = Rough/Low resolution + Remote/Dark light.
- Cones = Clear/High resolution + Color + Celestial/Bright light.
Deep-sea fishes often have only rods.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question compares the functional roles of two types of photoreceptor cells in the fish retina: rods and cones.
Detailed Explanation:

• Rods (Statement I): Rod cells are highly sensitive to light. They can be triggered by a very small number of photons, making them ideal for vision in dark or dim light conditions (scotopic vision). However, multiple rods usually converge on a single bipolar cell, which leads to low visual acuity or resolution. Thus, Statement I is true.

• Cones (Statement II): Cone cells have a much higher threshold for activation. They require relatively high light intensities to function (photopic vision). Cones provide high-resolution images and color vision because they typically have a more direct 1:1 connection to nerve cells. Thus, Statement II is true.

• Retinomotor movements: Fishes often exhibit "retinomotor movements" where rods and cones change position (shielding/unshielding by pigment) to adapt to changing light conditions throughout the day.

Step 2: Final Answer:
Both Statement I and Statement II are scientifically correct.