Question

Which plant hormone is primarily responsible for "triple response" in seedlings?

• A. Auxin
• B. Gibberellin
• C. Ethylene
• D. Cytokinin

Hint:

Ethylene is the only gaseous plant hormone and plays a key role in fruit ripening and stress responses.

Answer 1

The Correct Option is C

Concept: The triple response in seedlings is a characteristic growth pattern observed in response to a specific plant hormone, especially under stress or mechanical impedance.
Step 1: Understanding triple response.}
The triple response includes:

• Inhibition of stem elongation
• Radial swelling of the stem
• Horizontal growth (apical hook formation)

Step 2: Identifying the hormone.}
Ethylene is the plant hormone responsible for inducing the triple response in seedlings.
Step 3: Eliminating other options.}

• Auxin – Promotes elongation, not triple response.
• Gibberellin – Stimulates stem elongation.
• Cytokinin – Promotes cell division.