Plant growth regulators: auxin, gibberellin, cytokinin, ethylene, ABA Questions & Answers: NEET UG Botany

NEET UG 2025 question paper (official, booklet 45)

Full paper →

Which one of the following phytohormones promotes nutrient mobilization which helps in the delay of leaf senescence in plants?

4 marks · See worked answer →
Read the following statements on plant growth and development.
A. Parthenocarpy can be induced by auxins.
B. Plant growth regulators can be involved in promotion as well as inhibition of growth.
C. Dedifferentiation is a pre-requisite for re-differentiation.
D. Abscisic acid is a plant growth promoter.
E. Apical dominance promotes the growth of lateral buds.
Choose the option with all correct statements.

4 marks · See worked answer →

Full paper →

Auxin is used by gardeners to prepare weed-free lawns. But no damage is caused to grass as auxin

4 marks · See worked answer →
Spraying sugarcane crop with which of the following plant growth regulators, increases the length of stem, thus, increasing the yield?

4 marks · See worked answer →

Full paper →

Which hormone promotes internode/petiole elongation in deep water rice?

4 marks · See worked answer →
Spraying of which of the following phytohormone on juvenile conifers helps in hastening the maturity period, that leads to early seed production?

4 marks · See worked answer →

Full paper →

Production of Cucumber has increased manifold in recent years. Application of which of the following phytohormones has resulted in this increased yield as the hormone is known to produce female flowers in the plants :

4 marks · See worked answer →
The gaseous plant growth regulator is used in plants to :

4 marks · See worked answer →
Match List - I with List - II.
List - I: (a) Manganese (b) Magnesium (c) Boron (d) Iron
List - II: (i) Activates the enzyme catalase (ii) Required for pollen germination (iii) Activates enzymes of respiration (iv) Functions in splitting of water during photosynthesis
Choose the correct answer from the options given below :

4 marks · See worked answer →

Full paper →

The plant hormone used to destroy weeds in a field is :

4 marks · See worked answer →

Full paper →

Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop.

4 marks · See worked answer →
Which of the following is not an inhibitory substance governing seed dormancy ?

4 marks · See worked answer →

Full paper →

What is the site of perception of photoperiod necessary for induction of flowering in plants ?

4 marks · See worked answer →
It takes very long time for pineapple plants to produce flowers. Which combination of hormones can be applied to artificially induce flowering in pineapple plants throughout the year to increase yield ?

4 marks · See worked answer →

Full paper →

Fruit and leaf drop at early stages can be prevented by the application of :

4 marks · See worked answer →

Full paper →

Full paper →

You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?

4 marks · See worked answer →
Phytochrome is a

4 marks · See worked answer →