Plant Growth and Development Questions and Answers

1. The phenomenon called ‘apical dominance‘ in plants is due to a phytohormone—
A. Cytokinins
B. Auxins
D. gibberellins

2. Gibberellins can promote seed germination because of their influence on
A. absorption of water through hard seed coat
B. synthesis of abscisic acid
C. production of hydrolysing enzymes
D. rate of cell division

3. Which one of the following is correct for blooming of ‘short day‘ plants?
A. The long dark period is not critical.
B. It is affected by interruption of long dark period by brief exposure of light
C. It is not affected by interruption of long dark period by brief exposure of light.
D. It is affected if the continuous light period is interrupted.

4. Vernalisation promotes flowering by—
A. low temperature
B. high temperature
C. prolonged photoperiod
D. short photoperiod

5. The aleurone synthesises and secretes digestive enzymes that hydrolyse nutrients stored in the endosperm, in presence of-
A. Auxin
B. Gibberellin
C. cytokinin
D. ethylene

6. which of the following statements regarding photoperiodism is false?
A. The response of plants to periods of light/day is termed photoperiodism.
B. In day neutral plants there is no correlation between exposure to light duration and induction of flowering response.
C. Shoot apices modify themselves into flowering apices prior to flowering.
D. The site of perception of the light/dark duration is the flower.

7. Select the correctly matched pair-
A. Darwin and Darwin—Gibberellic acid
B. Went—Auxin
C. Kurosawa—Ethylene
D. Skoog and Miller—Abscisic acid

8. One hormone stimulates the closure of stomata and another one influences the swelling of the axis in dicot plants. They are-
A. Gibberellins and ethylene
B. Abscisic acid and cytokinins
C. Auxins and cytokinins
D. Abscisic acid and ethylene

9. Auxanometer is used to measure-
A. Growth
B. Respiration
C. Transpiration
D. ascent of sap

10. The light duration required for a plant to produce flowers is called——
A. Photoperiodism
B. critical day length
C. threshold light period
D. day light hours

11. The hormone that promotes rapid elongation of internode or petiole in deep water rice plant is-
A. abscisic acid
B. ethylene
C. cytokinin
D. gibberellin

12. Which of the following plant requires light exposure less than the critical period to initiate flowering?
A. Tobacco
B. Wheat
C. Spinach
D. Oat

13. The characteristics like expansion, breaking dormancy, promoting germination and flowering are associated with-
A. Auxins
B. Gibberellins
C. Cytokinins
D. Ethylene

14. 6-(4-Hydroxy-3 Methyl-trans-2-butenylamine) purine is also called-
A. Methyl jasmonate
B. Zeatin
C. Brassinolide
D. Triacontanol

15. A natural growth regulator is-—
A. 2, 4-D
B. Benzaldehyde
D. Ethylene

16. Assertion (A) : Ethylene induces ripening
Reason (R) : Ethylene is a gaseous hormone
A. A and R are true, R is correct explanation of A.
B. A and R are true but R is not the correct explanation
C. A is true, R is false
D. A is false, R is true

17. Identify the correct pair of combinations-
(i) Zeatin —— adenine derivative — overcoming apical dominance
(ii) C2H4—indole compound—effective in fruit ripening
(iii) ABA—carotenoid derivative—induction of parthenocarpy
(iv) GA3—terpene—bolting in cabbage
A. (ii), (iii)
B. (ii), (iv)
C. (i), (iv)
D. (iii), (iv)

18. Fruit and leaf drop at early stages can be prevented by the application of—
A. Cytokinins
B. Ethylene
C. Auxins
D. Gibberellic acid

19. 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?
A. Auxin and Cytokinin
B. Gibberellin and abscisic acid
C. Auxin and abscisic acid
D. IAA and gibberellin

20. The Avena curvature is used for bioassay of—-
A. GA3
B. Ethylene

Environmental Issues Excretory Products and their Elimination
Biodiversity and Conservation Body Fluids and Circulation
Ecosystem Breathing and Respiration
Organisms and Populations Digestion and Absorption
Biotechnology and its Application Plant Growth
Biotechnology Principles and Processes Respiration in Plants
Microbes in Human Welfare Photosynthesis
Strategies for Enhancement in Food Production Mineral Nutrition
Human Health and Disease Transport in Plants
Evolution Cell Cycle
Molecular Basic of Inheritance Biomolecules
Principle of Inheritance Cell the Unit of Life
Reproductive Health Structural Organisation
Human Reproduction Anatomy of Flowering Plants
Sexual Reproduction in Flowering Plants Morphology of Flowering Plants
Reproduction in Organisms Animal Kingdom
Chemical Coordination Plant Kingdom
Neural Control and Coordination Biological Classification
Locomotion and Movement The Living World

21. One hormone hastens maturity period in juvenile conifers, a second hormone controls xylem differentiation, while the third hormone increases the tolerance of plants to various stresses. They are respectively-
A. Auxin, Gibberellin, ABA
B. Gibberellin, Auxin, ABA
C. Auxin, Gibberellin, Cytokinin
D. Gibberellin, Auxin, Ethylene

22. Assertion : Plant growth regulators (PGRs) are very important for plant growth and development.
Reason : Auxins do not induce flowering in gymnosperms.
A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. lf both assertion and reason are false.

23. Auxin can be bioassayed by——
A. potometer
B. lettuce hypocotyl elongation
C. Avena coleoptile curvature
D. hydroponics

24. The cell derived from meristems differentiate and regain the capacity to divide by a phenomenon called—
A. Differentiation
B. Dedifferentiation
C. Redifferentiation
D. totipotency

25. Horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot seedlings is brought about by—
A. Auxins
B. Gibberellins
C. Ethylene
D. abscissic acid

26. Which of the following is a dicot weedicide—
A. 2, 4-D
D. lAA

27. During seed germination its stored food is mobilised by-
B. Gibberellin
C. ethylene
D. cytokinin

28. Assertion : On plotting the length of the root against time, a linear curve is obtained.
Reason: An elongating root exemplifies arithmetic growth.
A. Both true with reason being correct explanation
B. Both true but reason is not correct explanation.
C. Assertion true but reason is wrong.
D. Both are wrong.

29. Which of the following phytohormones promotes male flowering and parthenocarpy?
A. Auxin
B. Gibberellin
C. Cytokinin
D. Abscisic acid

30. In which plant heterophyllous development occurs due to environment.
A. Coriander
B. Cotton
C. Larkspur
D. Buttercup

31. Which statement regarding growth is false—
A. Increase in mass and increase in number of individuals are twin characteristics of growth
B. In plants, growth by cell division is seen only upto a certain stage
C. Growth exhibited by nonliving objects is by accumulation of material on the surface
D. A multicellular organism grows by cell division

32. The pineapple which under natural condition is difficult to blossom has been made to produce fruits throughout the year by application of——
A. NAA, 2, 4-D
B. phenyl acetic acid
C. cytokinin

33. The plant growth regulator kinetic is a/an –
A. adenine derivative
B. derivative of carotenoids
C. terpene
D. gas

34. Which plant hormone is basic in nature—
A. Gibberellin
B. Auxin
C. Ethylene
D. Cytokinin

35. One set of plants of a species was grown at 12 hours day and 12 hours night period cycles and it flowered while for the other set of the same plant, night phase was interrupted by flash of light and it did not produce flower. Under which one of the following categories will you place this plant-—
A. Long day plant
B. Darkness neutral plant
C. Day neutral plant
D. Short day plant

36. The viability of seeds is tested by-
A. 2, 6 dichlorophenol
B. 2, 3, 5 triphenyl tetrazolium chloride
D. safranine

37. Removal of apical bud makes the plant grow—
A. Tall
B. Bushy
C. Slow
D. Rapidly

38. Thermonastic movement is related to—
A. Light
B. Touch
C. Chemical
D. High temperature

39. Control of leaf, flower and fruit abscission and promotion of fruit reopening are functions of-
A. Ethylene
B. Auxin
C. Gibberellin
D. Cytokinin

40. Abscisic acid is known as the stress hormone because it—
A. breaks seed dormancy
B. induces flowering
C. promotes leaf fall
D. promotes closure of stomata.

41. Which one of the following generally acts as an antagonist to gibberellins?
A. Zeatin
B. Ethylene

42. Vernalisation is subjected to plants growing in-
A. Tropical areas
B. Sub tropical
C. Temperate areas
D. Hot areas/Arctic region

43. A few normal seedlings of tomato were kept in a dark room. After a few days they were found to have become while-coloured like albino. Which of the following terms will you use to describe them?
A. Mutated
B. Embolised
C. Etiolated
D. Defoliated

44. Dr. F. Went noted that if coleoptile tips were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly-cut coleptile stums. Of what significance is this experiment?
A. It demonstrated polar movement of auxins.
B. It supports the hypothesis that IAA is auxin.
C. It is the basis for quantitative determination of small amounts of growth-promoting substances.
D. lt made possible the isolation and exact identification of auxin.

45. Which one of the following growth regulators is known as ‘stress hormone’?
A. abscisic acid
B. Ethylene
D. Indole acetic acid

46. Which one of the following is a growth regulator produced by plants?
A. Naphthalene acetic acid
B. Zeatin
C. 2, 4—DichIorophenoxyacetic acid
D. Benzyl aminopurine

47. Which of the following plant growth hormones increases the yield of sugar by increasing the length of stem in sugarcane?
A. Cytokinin
B. Auxin
C. Abscisic acid
D. Gibberellic acid

48. Which of the following is not an effect of ethylene?
A. Promotes senescence and abscission of plant organs
B. Breaks seed and bud dormancy
C. Hastens fruit ripening
D. Helps to overcome apical dominance

49. If a plant produces flowers when exposed only to alternative periods of 5 hours light and 3 hours dark, in a 24-hour cycle, then the plant should be a—
A. short-long day plant
B. short day plant
C. day neutral plant
D. long day plant

50. The cell attaining their maximum size in terms of wall thickening and protoplasmic modification belong to—
A. meristematic phase of growth
B. elongation phase of growth
C. maturation phase of growth
D. none of the above

51. Coconut milk factor is a/an-—
A. abscisic acid
B. auxin
C. cytokinin
D. gibberellin

52. Length of grapes stalks increases due to–
A. Auxin
B. Cytokinins
C. gibbereIlins
D. ethylene

53. Cytokinin is not found in-
A. root apex
B. shoot apex
C. young fruits
D. mature fruits

54. In flowering plants, the site of perception of light/dark duration is-—
A. Stem
B. Leaves
C. Shoot apex
D. Floral meristem

55. Senescence in plants leads into of cells-—
A. increase in size
B. increase in number
C. death
D. differentiation