NEET Topic-wise & A
Topic 1: GROWTH, DIFFERENTIATION, DEDIFFERENTIATION & REDIFFERENTIATION, DEVELOPMENT
NEET: Previous Years Questions
01. Formation of interfascicular cambium from fully developed parenchyma cells is an example for
(1) Differentiation
(2) Redifferentiation
(3) Dedifferentiation
(4) Maturation (NEET 2024)
✅ (3) Dedifferentiation
02. In tissue culture experiments, leaf mesophyll cells are put in a culture medium to form callus. This phenomenon may be called as
(1) Dedifferentiation
(2) Development
(3) Senescence
(4) Differentiation (NEET 2023)
✅ (1) Dedifferentiation
03. Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called:
(1) Elasticity
(2) Flexibility
(3) Plasticity
(4) Maturity (NEET 2021)
✅ (3) Plasticity
04. The process of growth is maximum during:
(1) Senescence
(2) Dormancy
(3) Log phase
(4) Lag phase (NEET 2020)
✅ (3) Log phase
Model Questions
05. Growth is
(1) A reversible permanent increase in size of an organ or its parts or an individual cell.
(2) An irreversible permanent increase in size of an organ or its parts or an individual cell.
(3) A reversible temporary increase in size of an organ or its parts or an individual cell.
(4) An irreversible temporary increase in size of an organ or its parts or an individual cell.
✅ (2) An irreversible permanent increase in size of an organ or its parts or an individual cell.
06. Plant growth continues throughout the life due to the presence of
(1) Meristems
(2) Parenchyma
(3) Cambium
(4) Collenchyma
✅ (1) Meristems
07. The growth where new cells are always added to the plant body by the meristem is called
(1) Primary growth
(2) Secondary growth
(3) Open form of growth
(4) Arithmetic growth
✅ (3) Open form of growth
08. In plants, primary growth occurs due to
(1) Lateral meristems & Vascular cambium
(2) Root apical meristem & shoot apical meristem
(3) Vascular cambium & cork cambium
(4) Apical meristems & lateral meristems
✅ (2) Root apical meristem & shoot apical meristem
09. In gymnosperms and dicots, secondary growth takes place due to
(1) Apical meristems & lateral meristems
(2) Lateral meristems, apical meristems & vascular cambium
(3) Apical meristems, vascular cambium & lateral meristems
(4) Lateral meristems, vascular cambium & cork-cambium
✅ (4) Lateral meristems, vascular cambium & cork-cambium
10. At cellular level, growth occurs due to increase in the amount of
(1) Protoplasm
(2) Cytoplasm
(3) Nucleoplasm
(4) Endoplasm
✅ (1) Protoplasm
11. A maize root apical meristem can produce more than
(1) 17,500 new cells per day
(2) 17,500 new cells per hour
(3) 1750 new cells per day
(4) 1750 new cells per hour
✅ (2) 17,500 new cells per hour
12. Cells in a watermelon can increase in size by up to
(1) 350 times
(2) 3500 times
(3) 35,000 times
(4) 3,50,000 times
✅ (4) 3,50,000 times
13. In which growth phase, the cells have increased vacuolation, size and new cell wall deposition?
(1) Meristematic phase
(2) Elongation phase
(3) Maturation phase
(4) Lag phase
✅ (2) Elongation phase
14. In arithmetic growth, following mitotic division,
(1) All daughter cell continues to divide
(2) All daughter cells stop division & differentiation
(3) Only one daughter cell continues to divide while the other differentiates & matures
(4) All daughter cells differentiate & mature
✅ (3) Only one daughter cell continues to divide while the other differentiates & matures
15. In arithmetic growth, on plotting the length of the organ against time, we get
(1) Linear curve
(2) Sigmoid curve
(3) Hyperbola
(4) Parabola
✅ (1) Linear curve
16. The diagram given below represents
(1) Arithmetic growth
(2) Geometric growth
(3) Primary growth
(4) Secondary growth
✅ (2) Geometric growth
17. Given below is a graph representing geometrical growth. Label A, B and C.
(1) A= Log phase, B= Lag phase, C= stationary phase
(2) A= Lag phase, B= stationary phase, C= Log phase
(3) A= Log phase, B= stationary phase, C= Lag phase
(4) A= Lag phase, B= Log phase, C= stationary phase
✅ (4) A= Lag phase, B= Log phase, C= stationary phase
18. In geometric growth, exponential growth is expressed as
(1) W₁ = W₀ eʳᵗ
(2) W₁ = W₀ ert
(3) L₁ = L₀ rt
(4) Lₑ = Lₜ rt
✅ (1) W₁ = W₀ eʳᵗ
19. In the formula W₁= W₀ eʳᵗ, W₁ means
(1) Initial size
(2) Final size
(3) Growth rate
(4) Base of natural logarithm
✅ (2) Final size
20. In what way water becomes an essential element for plant growth?
(1) It is needed for cell enlargement
(2) It increases the turgidity of cells that helps in extension growth
(3) It provides medium for enzymatic activities needed for growth
(4) All the above
✅ (4) All the above
21. The process in which the cells in meristems (root apical & shoot-apical) and cambium diverge and mature to perform specific functions is known as
(1) Differentiation
(2) Dedifferentiation
(3) Redifferentiation
(4) Expansion
✅ (1) Differentiation
22. Formation of meristems like interfascicular cambium and cork cambium from differentiated parenchyma cells is an example for
(1) Expansion
(2) Dedifferentiation
(3) Development
(4) Redifferentiation
✅ (2) Dedifferentiation
23. Which correctly describes the process of development?
(1) Development= dedifferentiation + differentiation
(2) Development= growth + redifferentiation
(3) Development= growth + differentiation
(4) Development= differentiation + elongation
✅ (3) Development= growth + differentiation
24. Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called
(1) Plasticity
(2) Photoperiodism
(3) Vernalization
(4) Differentiation
✅ (1) Plasticity
25. Regarding the factors controlling the plant development, select the odd one out.
(1) Light
(2) Temperature
(3) Nutrition
(4) Growth regulator
✅ (4) Growth regulator
26. Which of the following plants shows Heterophylly due to environment?
(1) Cotton
(2) Coriander
(3) Buttercup
(4) Larkspur
✅ (3) Buttercup
27. Complete A, B, C and D.
(1) A= plasmatic growth, B= cell division, C= Maturation, D= Senescence
(2) A= cell division, B= plasmatic growth, C= Maturation, D= Senescence
(3) A= cell division, B= Maturation, C= plasmatic growth, D= Senescence
(4) A= plasmatic growth, B= Maturation, C= cell division, D= Senescence
✅ (2) A= cell division, B= plasmatic growth, C= Maturation, D= Senescence
Topic 2: PLANT GROWTH REGULATORS (PLANT HORMONES / PHYTOHORMONES)
NEET: Previous Years Questions
28. Auxin is used by gardeners to prepare weed-free lawns. But no damage is caused to grass as auxin
(1) promotes apical dominance.
(2) promotes abscission of mature leaves only.
(3) does not affect mature monocotyledonous plants.
(4) can help in cell division in grasses, to produce growth. (NEET 2024)
✅ (3) does not affect mature monocotyledonous plants.
29. Spraying sugarcane crop with which of the following plant growth regulators, increases the length of stem, thus, increasing the yield? (NEET 2024)
(1) Auxin
(2) Gibberellin
(3) Cytokinin
(4) Abscisic acid
✅ (2) Gibberellin
30. Spraying of which of the following phytohormone on juvenile conifers helps hastening the maturity period, the leads early seed production? (NEET 2023)
(1) Gibberellic Acid
(2) Zeatin
(3) Abscisic Acid
(4) Indole-3-butyric Acid
✅ (1) Gibberellic Acid
31. Which hormone promotes internode /petiole elongation in deep water rice? (NEET 2023)
(1) Kinetin
(2) Ethylene
(3) 2, 4-D
(4) GA3
✅ (2) Ethylene
32. The plant hormone used to destroy weeds in a field is: (NEET 2021)
(1) IAA
(2) NAA
(3) 2,4-D
(4) IBA
✅ (3) 2,4-D
33. Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop.
(1) Ethylene
(2) Abscisic acid
(3) Cytokinin
(4) Gibberellin (NEET 2020)
✅ (4) Gibberellin
34. Which of the following is not an inhibitory substance governing seed dormancy? (NEET 2020)
(1) Phenolic acid
(2) Para-ascorbic acid
(3) Gibberellic acid
(4) Abscisic acid
✅ (3) Gibberellic acid
35. It takes very long time for pineapple plants to produce flowers. Which combination of hormones can be applied to artificially induce flowering in pineapple plants throughout the year to increase yield?
(1) Auxin and Ethylene
(2) Gibberellin and Cytokinin
(3) Gibberellin and Abscisic acid
(4) Cytokinin and Abscisic acid (NEET 2019)
✅ (1) Auxin and Ethylene
36. Fruit and leaf drop at early stages can be prevented by the application of
(1) ethylene
(2) auxins
(3) gibberellic acid
(4) cytokinins (NEET 2017)
✅ (2) auxins
37. 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?
(1) IAA and gibberellin
(2) Auxin and cytokinin
(3) Auxin and abscisic acid
(4) Gibberellin and abscisic acid (NEET-II 2016)
✅ (2) Auxin and cytokinin
38. The Avena curvature is used for bioassay of
(1) IAA
(2) ethylene
(3) ABA
(4) GA3 (NEET-I 2016)
✅ (1) IAA
Model Questions
39. Which of the following is not plant growth promoter?
(1) Auxins
(2) Gibberellins
(3) Cytokinins
(4) Abscisic acid
✅ (4) Abscisic acid
40. Select the PGR that can act as either plant growth promoter or plant growth inhibiter.
(1) ABA
(2) Ethylene
(3) Auxins
(4) Gibberellin
✅ (2) Ethylene
41. Who isolated Auxin from tips of coleoptiles of oat seedlings?
(1) F.W. Went
(2) Charles Darwin
(3) Skoog & Miller
(4) E. Kurosawa
✅ (1) F.W. Went
42. Which of the following are synthetic Auxins?
(1) Indole-3-acetic acid (IAA) and indole butyric acid (IBA)
(2) NAA (naphthalene acetic acid) and 2, 4-D (2, 4-dichlorophenoxyacetic)
(3) NAA (naphthalene acetic acid) and indole butyric acid (IBA)
(4) 2, 4-D (2, 4-dichlorophenoxyacetic) and Indole-3-acetic acid (IAA)
✅ (2) NAA (naphthalene acetic acid) and 2, 4-D (2, 4-dichlorophenoxyacetic)
43. Which of the following pairs is not correctly matched?
(1) Adenine derivative – Kinetin
(2) Carotenoid derivative – ABA
(3) Terpenes – IAA
(4) Indole compounds – IBA
✅ (3) Terpenes – IAA
44. Match the following:
(1) A-2, B-5, C-1, D-3, E-4
(2) A-2, B-3, C-4, D-5, E-1
(3) A-1, B-5, C-2, D-4, E-3
(4) A-5, B-4, C-3, D-2, E-1
✅ (1) A-2, B-5, C-1, D-3, E-4
45. Auxins promote
(1) Cell growth and enlargement
(2) Apical dominance
(3) Parthenocarpy
(4) All the above
✅ (4) All the above
46. Which is used as weedicide?
(1) 2, 4-D
(2) IBA
(3) IAA
(4) ABA
✅ (1) 2, 4-D
47. The following statements are given about plant growth hormones:
i. Cytokinin suppress the synthesis of chlorophyll
ii. Auxin control apical dominance
iii. Gibberellins promote shoot elongation
iv. ABA enables seeds to withstand desiccation
Which of the above statements are correct?
(1) i and ii
(2) ii and iii
(3) i and iii
(4) ii, iii and iv
✅ (4) ii, iii and iv
48. The stress hormone that helps plant to respond drought
(1) Auxins
(2) Abscisic acid
(3) Cytokinin
(4) Ethylene
✅ (2) Abscisic acid
49. Regarding gibberellins, which statement is wrong?
(1) GA3 or Terpenes is one of the first discovered and most intensively studied gibberellins.
(2) Gibberellins cause an increase in length of axis.
(3) Gibberellins stimulates senescence.
(4) Spraying juvenile conifers with GAs hastens the maturity period.
✅ (3) Gibberellins stimulates senescence.
50. Internode elongation just prior to flowering in plants such as beet, cabbages and many plants with rosette habit is called
(1) Bolting
(2) Pruning
(3) Abscission
(4) Apical dominance
✅ (1) Bolting
51. Coconut milk stimulates cell division as it is rich in
(1) Auxin
(2) Ethylene
(3) Gibberellin
(4) Cytokinin
✅ (4) Cytokinin
52. Match the following:
(1) A-2, B-5, C-1, D-3, E-4
(2) A-2, B-3, C-4, D-5, E-1
(3) A-3, B-5, C-2, D-1, E-4
(4) A-5, B-4, C-3, D-2, E-1
✅ (3) A-3, B-5, C-2, D-1, E-4
53. Natural cytokinins are mainly synthesized in regions of
(1) Photosynthesis such as leaves & tender stems.
(2) Rapid cell division such as root apices, shoot buds, young fruits etc.
(3) Ripened fruits and senescent leaves.
(4) Vascular tissues such as xylem and phloem.
✅ (2) Rapid cell division such as root apices, shoot buds, young fruits etc.
54. Given below are some statements regarding ethylene. Pick out the false statements.
(1) The most widely used source of ethylene is ethephon.
(2) Ethephon in an aqueous solution is readily absorbed and transported within the plant and releases ethylene slowly.
(3) Ethephon hastens fruit ripening in tomatoes & apples and accelerates abscission in flowers and fruits.
(4) It obstructs female flowers in cucumbers thereby decreasing the yield.
✅ (4) It obstructs female flowers in cucumbers thereby decreasing the yield.
55. During mid-1960s, it was reported 3 kinds of inhibitors: inhibitor-B, abscisin II & dormin. They were chemically identical and now known as
(1) Ethylene
(2) ABA
(3) Gibberellin
(4) NAA
✅ (2) ABA
56. In most situations, ABA acts as an antagonist to
(1) GAs
(2) Ethylene
(3) Cytokinin
(4) Auxin
✅ (1) GAs
Topic 3: ROLE OF LIGHT AND TEMPERATURE ON FLOWERING
NEET: Previous Years Questions
57. The site of perception of light in plants during photoperiodism is:
(1) Shoot apex
(2) Stem
(3) Axillary bud
(4) Leaf (NEET 2021)
✅ (4) Leaf
58. What is the site of perception of photoperiod necessary for induction of flowering in plants?
(1) Lateral buds
(2) Pulvinus
(3) Shoot apex
(4) Leaves (NEET 2019)
✅ (4) Leaves
Model Questions
59. Importance of day length in flowering of plants was first shown in
(1) Lemna
(2) Tobacco
(3) Cotton
(4) Petunia
✅ (2) Tobacco
60. Day-neutral plant relates to
(1) Loss of activity during day time
(2) Overactive during day time
(3) Flowering in all possible photoperiods
(4) No flowering in any photoperiod
✅ (3) Flowering in all possible photoperiods
61. The phenomenon in which some plants depend quantitatively or qualitatively on exposure to low temperature for flowering is called
(1) Photoperiodism
(2) Vernalisation
(3) Plasticity
(4) Phototropism
✅ (2) Vernalisation
62. Select the wrong statement:
(1) Some food plants, wheat, barley & rye have two varieties-spring varieties and winter varieties.
(2) Winter varieties if planted in spring would normally fail to flower or produce mature grain within a span of a flowering season. Hence, they are planted in autumn.
(3) Biennials are monocarpic plants that normally flower and die in second season.
(4) Subjecting the growing of a biennial plant to a cold treatment prevents a subsequent photoperiodic flowering response.
✅ (4) Subjecting the growing of a biennial plant to a cold treatment prevents a subsequent photoperiodic flowering response.