Ques. 1AIPMT 2001
Which of the following prevents the fall of fruits?
- GA3
- NAA
- Ethylene
- Zeatin
Answer
(2) NAA
Solution
As per NCERT, auxins (IAA, IBA and synthetic auxins such as NAA and 2,4-D) prevent fruit and leaf drop at early stages, but promote the abscission of older mature leaves and fruits.
∵ Ethylene promotes abscission of fruits, and gibberellins / zeatin (a cytokinin) are not used to check fruit fall,
∴ NAA prevents the premature fall of fruits.
Answer: (2)