Question

Which of the following is responsible for apical dominance?

• A. GA${}_3$
• B. IAA
• C. ABA
• D. Florigen

Answer 1

Answer: (B)

Auxin is a general name for a group of hormones that are involved with growth responses. The most important auxin found in plants is indole-3-acetic acid.

Auxins are known to play a role in apical dominance. In most plants, the growing apical tip inhibits the growth of lateral buds. This is known as apical dominance. If the terminal or apical tip of the plant is removed lateral buds will elongate and grow. It is further known that if auxin is applied to the severed shoot tip, the lateral buds will remain suppressed. Thus, the correct answer is option B.