Plant Growth and Development

Plant Growth Regulators Practice Questions

20 free Plant Growth Regulators practice questions for the NCERT Biology, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.

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All Plant Growth Regulators questions

20 questions
  1. Q1. The term 'Auxin' was first isolated from which of the following sources?
  2. Q2. Which of the following plant growth regulators is responsible for the 'bakanae' (foolish seedling) disease in rice?
  3. Q3. F.W. Went demonstrated the presence of auxins by performing experiments on the coleoptile tips of:
  4. Q4. Which specific combination of hormones is often used in tissue culture to induce shoot and root differentiation?
  5. Q5. Apical dominance, the phenomenon where the apical bud inhibits the growth of lateral buds, is primarily caused by:
  6. Q6. Which plant growth regulator is used to speed up the malting process in the brewing industry?
  7. Q7. Which hormone is a gaseous plant growth regulator?
  8. Q8. What is the primary effect of Abscisic acid (ABA) on stomata during water stress?
  9. Q9. The 'triple response' in seedlings (shortening of the axis, thickening of the axis, and horizontal growth) is a characteristic effect of:
  10. Q10. Which synthetic auxin is widely used as a weedicide to kill broad-leaved dicotyledonous weeds?
  11. Q11. Bolting, the internode elongation just prior to flowering in rosette plants like beet and cabbage, is induced by:
  12. Q12. Kinetin, a modified form of adenine, was first discovered from:
  13. Q13. Which hormone is used to induce parthenocarpy (seedless fruit formation) in tomatoes?
  14. Q14. The respiratory climacteric, an increase in respiration rate during fruit ripening, is triggered by:
  15. Q15. Which hormone acts as a general plant growth inhibitor and antagonist to Gibberellins?
  16. Q16. Cytokinins are primarily synthesized in regions where:
  17. Q17. Ethephon, the most widely used source of ethylene, is primarily used to:
  18. Q18. Which of the following hormones helps to overcome apical dominance?
  19. Q19. Spraying sugarcane crops with which hormone can increase the yield by as much as 20 tonnes per acre?
  20. Q20. The physiological effect of 'Thinning' in cotton, cherry, and walnut is achieved using: