Question

Match the following related to adaptations in response to light in organisms

• A. (i-d-q), (ii-c-p), (iii-b-s), (iv-a-r)
• B. (i-c-p), (ii-d-q), (iii-a-r), (iv-b-s)
• C. (i-c-d), (ii-a-r), (iii-d-q), (iv-b-p)
• D. (i-d-q), (ii-c-s), (iii-b-p), (iv-a-r)

Hint:

Phototaxis = movement, Phototropism = growth response, Kinesis = non-directional movement.

Answer 1

The Correct Option is A

Step 1: Understanding light responses in organisms.
Organisms respond to light through different behavioral and growth mechanisms. These include movement (taxes), non-directional responses (kinesis), and growth-based responses (tropism).

Step 2: Photokinesis (non-directional movement).
Photokinesis refers to change in movement speed due to light intensity without a specific direction. It is seen in organisms like larvae of Pinnotheres maculatus.

Step 3: Positive phototaxis.
Positive phototaxis is movement of organisms towards light source. Euglena is a classic example showing movement towards light for photosynthesis.

Step 4: Negative phototaxis.
Negative phototaxis is movement away from light. Cockroach shows this behavior as it prefers dark environments to avoid light exposure.

Step 5: Phototropism in plants.
Phototropism is directional growth response of plants towards light. It is not movement but growth-based orientation seen in plants.

Step 6: Final matching conclusion.
Correct matching becomes: (i-d-q), (ii-c-p), (iii-b-s), (iv-a-r), which fits biological definitions accurately.