Chapter 15: Plant Growth and Development — Online MCQ Test
BOTANY · CLASS 11th · Tamil Nadu State Board
Practice Chapter 15: Plant Growth and Development with a free chapter-wise online MCQ test.
This chapter covers: The final chapter covers plant growth kinetics hormones including auxins gibberellins cytokinins ethylene and ABA. Students explore photoperiodism vernalization seed dormancy and p....
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 15: Plant Growth and Development — Important Questions & Answers
Which plant hormone is primarily responsible for apical dominance?
- A. Auxin
- B. Gibberellin
- C. Cytokinin
- D. Ethylene
Answer: A. Auxin
Auxin is produced in the apical meristem and inhibits the growth of lateral buds, a phenomenon known as apical dominance.
Auxin is produced in the apical meristem and inhibits the growth of lateral buds, a phenomenon known as apical dominance.
What is the primary effect of Gibberellins on plants?
- A. Root initiation
- B. Stem elongation
- C. Leaf senescence
- D. Fruit ripening
Answer: B. Stem elongation
Gibberellins are well known for promoting internode elongation in genetically dwarf plants.
Gibberellins are well known for promoting internode elongation in genetically dwarf plants.
Which plant hormone is commonly known as the 'stress hormone'?
- A. Auxin
- B. Cytokinin
- C. Abscisic Acid (ABA)
- D. Gibberellin
Answer: C. Abscisic Acid (ABA)
ABA is called the stress hormone because it increases plant tolerance to various stresses, particularly water stress by closing stomata.
ABA is called the stress hormone because it increases plant tolerance to various stresses, particularly water stress by closing stomata.
If a plant is exposed to light from only one side, which hormone redistributes to the shaded side causing bending?
- A. Gibberellin
- B. Abscisic acid
- C. Auxin
- D. Cytokinin
Answer: C. Auxin
Auxin accumulates on the shaded side, promoting faster cell elongation there, which causes the plant to bend towards the light.
Auxin accumulates on the shaded side, promoting faster cell elongation there, which causes the plant to bend towards the light.
Consider a long-day plant. Which of the following treatments would most likely lead to flowering in the middle of winter in a greenhouse?
- A. Extending the night period using artificial lights
- B. Exposing the plant to a flash of light during the dark period
- C. Applying high concentrations of ABA
- D. Keeping the temperature at freezing levels
Answer: B. Exposing the plant to a flash of light during the dark period
Long-day plants are sensitive to the night length. Interrupting the dark period with a flash of light tricks the plant into sensing a shorter night, triggering flowering.
Long-day plants are sensitive to the night length. Interrupting the dark period with a flash of light tricks the plant into sensing a shorter night, triggering flowering.