Question

Apical dominance is mainly caused by:

• A. Cytokinin
• B. Gibberellin
• C. Auxin
• D. Ethylene Correct Answer: (C) Auxin

Hint:

To easily remember this for your botanical exams, associate Auxin with the Apex! Since Auxin is made at the Apex, it rules over the rest of the plant stem, enforcing Apical dominance. If you want a plant to grow wide instead of tall, chop the apex off to break the spell!

Answer 1

The Correct Option is C

Step 1: Understand apical dominance.
Apical dominance means the top shoot tip stops the side buds from growing. So the plant grows tall instead of bushy.

Step 2: Find the hormone behind it.
The tip makes a hormone called auxin. This auxin moves down the stem and keeps the side buds asleep.

Step 3: Confirm with a simple test.
If you cut off the top tip, the auxin source is gone and the side buds wake up and grow. This shows auxin was the cause.

Step 4: Final choice.
Apical dominance is mainly due to auxin, which is option 3.
\[ \boxed{\text{Auxin}} \]