Adenine is the precursor of cytokinins.
Important Questions on Plant Growth and Development
Match the plant hormones in Column I with their primary function in Column II.
| Column I | Column II |
| P. Abscisic acid | i. Promotes disease resistance |
| Q. Ethylene | ii. Maintains seed dormancy |
| R. Cytokinin | iii. Promotes seed germination |
| S. Gibberellins | iv. Promotes fruit ripening |
| v. Inhibits leaf senescence |
Choose the correct combination:
Observe the given set of physiological activities regulated by different plant growth regulators and list out the number of activities promoted by auxins, cytokinin, gibberellin and ethylene, respectively.
a) Xylem differentiation
b) Improvement of the shape of an apple
c) Hastening the apple ripening
d) Delay of senescence
e) Promote nutrient mobilization
f) Lateral and adventitious shoot growth
g) Root growth and root hair formation
h) Increase of root absorption surface
Withstand desiccation and other factors unfavourable for growth
Promotes female flowers in cucumber
Increase absorption surface
Rapid elongation in internodes
Assertion The foolish seedling disease in rice seedlings is caused by a fungal pathogen, Gibberella fuzikuroi.
Reason E. Kurosawa reported the appearance of symptoms of the disease in uninfected rice seedlings when they were treated with sterile filtrates of the fungus and the active principle was identified as gibberellic acid.
The correct answer is:
Statement (I): Auxin promotes apical dominance by suppressing the activity of lateral buds.
Statement (II): In moriculture, periodic pruning of shoot tips is done to make mulberry plants bushy.
Choose the correct options.
