CHAPTER 13: PLANT GROWTH AND DEVELOPMENT
EXERCISES
1. Define growth, differentiation, development, dedifferentiation,
redifferentiation, determinate growth, meristem and growth rate.
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2. Why is not any one parameter good enough to demonstrate growth
throughout the life of a flowering plant?
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3. Describe briefly:
(a) Arithmetic growth
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(b) Geometric growth
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(c) Sigmoid growth curve
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(d) Absolute and relative growth rates
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4. List five main groups of natural plant growth regulators. Write a note on discovery, physiological functions and agricultural/horticultural applications of any one of them.
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5. Why is abscisic acid also known as stress hormone?
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6. ‘Both growth and differentiation in higher plants are open’. Comment.
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7. ‘Both a short day plant and a long day plant can produce can flower simultaneously in a given place’. Explain.
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8. Which one of the plant growth regulators would you use if you are
asked to:
(a) induce rooting in a twig
(b) quickly ripen a fruit
(c) delay leaf senescence
(d) induce growth in axillary buds
(e) ‘bolt’ a rosette plant
(f) induce immediate stomatal closure in leaves.
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9. Would a defoliated plant respond to photoperiodic cycle? Why?
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10. What would be expected to happen if:
(a) GA3 is applied to rice seedlings
(b) dividing cells stop differentiating
(c) a rotten fruit gets mixed with unripe fruits
(d) you forget to add cytokinin to the culture medium.
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