300+ TOP MCQs on Plant Physiology and Answers

Plant Physiology Multiple Choice Questions

1. Element present in nucleic acids, Phospholipids, ATP, ADP and NADPH is ______

A. P

B. Na

C. Bo

D. Co

Answer: A

2. ______ are required for chlorophyll synthesis

A. Fe and Mg

B. Fe and Co

C. Cu and Ca

D. Mg and Ca

Answer: A

3. In which form Ca is present in plants?

A. Calcium pectate

B. Calcium carbonate

C. Calcium

D. CaCl

Answer: A

4. Nitrate reductase system in which element is major component?

A. Mo

B. N

C. H

D. None of the above

Answer: A

5. Which element is essential for activating the enzyme but not a part of enzyme?

A. Mn

B. Mg

C. K

D. Co

Answer: C

6. For the selective permeability of the cell membranes which element is involved?

A. K

B. Fe

C. P

D. Ca

Answer: D

7. Which element is essential for pollen germination?

A. Na

B. B

C. Mo

D. Co

Answer: B

8. In photosynthesis which element is essential for the evolution of oxygen?

A. CI

B. Mg

C. Fe

D. All of the above

Answer: A

9. In leguminous plants leghemoglobin protects _____ activity

A. Nitrogenase

B. Protiase

C. Nitrate reductase

D. Both A and B

Answer: C

10. In Nitrogen fixation and metabolism which element is play major role?

A. Mn

B. B

C. Mg

D. Mo

Answer: D

11. Main source of elements for nitrate reductase is ferredoxin which is present in ______

A. Endoplasmic reticulum

B. Mitochondria

C. Chloroplasts

D. Golgi complex

Answer: C

12. Nitrobacter convert NO2 into NO3 in which process

A. Reduction

B. Oxidation

C. Both A and B

D. None of the above

Answer: B

13. Which element responsible of an anaerobic nitrogen fixing bacteria, Clostridium is _____

A. Potassium

B. Phosphorous

C. Nitrogen

D. Sodium

Answer: A

14. In plant ______ is responsible for guttation

A. Root pressure

B. Photosynthesis

C. Transpiration

D. Osmosis

Answer: A

15. Root pressure introduced by Stephen Hales and it is absent in _______

A. Mango

B. Dicots

C. Gymnosperms

D. None of the above

Answer: C

16. Which is selectively permeable membrane of the cell ______

A. Cell wall

B. Cytoplasm

C. Plasmalemma

D. None of the above

Answer: C

17. Which plants Scotoactive stomata perform

A. C3 photosynthesis

B. C4 photosynthesis

C. Both A and B

D. CAM photosynthesis

Answer: D

18. The chemical use an antitranspirant is ______

A. Salicylic acid

B. Abscisic acid

C. Phenylmercuric acid

D. All of the above

Answer: D

19. Sub epidermal evaporation of water exhibit in plant during

A. Photosynthesis

B. Guttation

C. Respiration

D. Transpiration

Answer: D

20. The best light for stomatal opening is ______

A. Red

B. Yellow

C. Green

D. Blue

Answer: D

21. During high wind velocity, the stomata of plants ______

A. Remain open

B. Close down

C. Open more widely

D. Remain unaffected

Answer: B

22. Optimum temperature for water absorption is ______

A. 0 – 5 °C

B. 20 – 25 °C

C. 45 – 65°C

D. 5 – 20°C

Answer: B

23. The transport of sap from root to top of the dicot plant is ______

A. Transport

B. Translocation

C. Ascent of sap

D. All of the above

Answer: C

24. Selective passage across a semipermeable membrane is called ______

A. Osmosis

B. Diffusion

C. Both A and B

D. Imbibition

Answer: A

25. Stomata open at night but close during day time in which plants?

A. Xerophytes

B. Mesophytes

C. Succulents

D. Both A and B

Answer: C

26. In the plant number of stomata present per cm of a common leaf is about

A. 2 million

B. More then 100000

C. 10000

D. Less than 1000

Answer: B

27. The most important factor in stomatal opening in the plant is ______

A. Protein percentage of sap

B. Shape of guard cells

C. Hormone content of cell

D. Chlorophyll content in cell

Answer: B

28. Which plant hormone is associated with closing of stomata?

A. IBA

B. GA

C. ABA

D. All of the above

Answer: C

29. Which enzyme plays major role in opening and closing of stomata?

A. Beta-amylase

B. Pyruvic kinase

C. RuDP

D. PEP carboxylase

Answer: D

30. Absorption of water and minerals take place in which part of root?

A. Root cap tip

B. Root hairs

C. Root epidermis

D. Root endodermis

Answer: B

31. The highest root pressure exhibit in plants is _________

A. 4 bars

B. 15 bars

C. 10 bars

D. None of the above

Answer: B

32. Which nutrient is obtained by insectivorous plants from insect bodies?

A. P

B. K

C. N

D. Na

Answer: C

33. In Himalayan forest commonly N2 fixing bacteria is _____

A. Azotobacter

B. Frankia

C. Nitrobacter

D. None of the above

Answer: B

34. The enzyme responsible for atmospheric nitrogen fixation is _____

A. Nitrogenase

B. Amylase

C. Nitrogenase and Amylase

D. Lemda nitrogenage

Answer: A

35. In which method ions are absorbed by plants

A. By carriers and pumps

B. By carriers method

C. By difference in DPD

D. By molecular diffusion

Answer: A

36. The most effective cofactor for enzyme is ______

A. Mn

B. Na

C. K

D. Ca

Answer: C

37. Flowering plants adapted to absorb which ions

A. NO3

B. NO3+2

C. NH3

D. NO2

Answer: A

38. Bidirectional translocation of minerals occurs in plants

A. Phloem

B. Xylem

C. Cambium

D. Perenchyma and phloem

Answer: A

39. Nodule formation of legume roots is reduced during deficiency of _____

A. S and B

B. N

C. K

D. CI

Answer: A

40. Boron help in _________

A. Photosynthesis

B. Sugar transport

C. Acting as a co-factors

D. Both A and C

Answer: B

41. Nitrification process is done by _____

A. Rhizobium

B. B. bassiana

C. Pseudomonas

D. Nitrococcus

Answer: A

42. Transpiration mostly affected by _____

A. Humidity

B. Temperature

C. Light

D. Wind

Answer: A

43. Transpiration pull help in passive absorption of water that depends on ______

A. Negative water potential of atm.

B. Cohesion and adhesion of water

C. Positive water potential

D. Both B and C

Answer: A

44. In plants stomatal movement is known as ______

A. Nastic movement

B. Physiotactic movement

C. Geotactic movement

D. Phototaxic movement

Answer: A

45. Which enzyme is not proteinaceous in nature?

A. Ribozyme

B. Both A and B

C. Isozyme

D. Trypsin

Answer: A

46. Below the freezing point enzyme are inactivated but at which temperature activity would be maximum?

A. 22°C

B. 35°C

C. 54°C

D. 25°C

Answer: B

47. Phosphofructokinase major enzyme in glycolysis is inhibited by _________

A. ATP

B. ADP

C. Citrate

D. Both A and C

Answer: D

48. Pyruvate dehydrogenease complex and glycolytic pathway is located in __________

A. Cytosol and Mitochondria

B. Cytosol

C. Golgi bodies

D. Microsomes

Answer: A

49. Which is responsible for Acetyl CoA carboxylase activation

A. Citrate and insulin

B. Isozyme

C. Trypsin

D. All of the above

Answer: A

50. Most C4 plants are native _____

A. Xerix habitats

B. Merine habitats

C. Grass habitats

D. All habitats

Answer: A

51. Photosynthetic yield will be maximum in ________

A. Intermittent white light

B. Continuous blue light

C. Red light

D. Yellow light

Answer: A

52. Photosynthetically active radiation wavelength ranging from ______

A. 340 – 450

B. 200 – 300

C. 400 – 700

D. 640 – 650

Answer: C

53. Which is involve in photosynthesis

A. Blackman and Hill

B. Krebs cycle reaction

C. E.M.P. Pathway

D. None of the above

Answer: A

54. Hill reaction take place in Granna formed

A. ATP and NADPH2 both

B. NADPH2

C. ADP

D. All of the above

Answer: A

55. Photosynthesis is most active and fast in _______

A. Blue light

B. White light

C. Red light

D. UV light

Answer: C

56. Which is immediate electron donor to PS-I

A. Plastocyanin

B. Plastometheonin

C. Ferredoxinin

D. Both B and C

Answer: A

57. Anabolic process is _____

A. Photosynthesis

B. Transpiration

C. Both A and B

D. None of the above

Answer: A

58. Absorption of light take place during photosynthesis

A. Photosystem-I only

B. Photosystem-II only

C. Photosystem-I and Photosystem-II

D. None of the above

Answer: C

59. In C4 pathway

A. O2 combine with PGA

B. CO2 combine with PEP

C. CO2 combine with RMP

D. All of the above

Answer: B

60. Dark reaction of photosynthesis occurs in ______

A. Stomata

B. Stroma and matrix

C. Stroma

D. Granna

Answer: C

61. In C4 plants first CO2 acceptor is _________

A. Oxaloacetic acid

B. Phosphoenol-pyruvate

C. Oxalo butaric acid

D. Pyruvic acid

Answer: B

62. Kranz anatomy found in ______

A. Leaves

B. Stem

C. Flower

D. Seed

Answer: C

63. Calvin cycle involves reductive carboxylation occurs in ________

A. Chloroplast

B. Cytochrom

C. Peroxisome

D. Cytoplasm

Answer: A

64. RUBISCO content of chlorophyll is _________

A. 10%

B. 15%

C. 5%

D. 7%

Answer: C

65. Dye used in Hill reaction by Stephan Hill

A. Methylene blue

B. Erosine

C. Sulphure green

D. Both A and B

Answer: C

66. First stable product of C4 photosynthesis is __________

A. Malic acid

B. Rubilose 1, 5, biophosphate

C. Phosphoglyceric acid

D. Both B and C

Answer: A

67. At which time acid concentration in CAM plants is maximum

A. Dusk

B. Down

C. Night

D. Day

Answer: B

68. During photosynthesis which element is essential for photolysis of water?

A. Co

B. C

C. Cl

D. N

Answer: C

69. Respiratory quotient (R.Q.) is less than one when the respiratory substrate is ______

A. Sucrose

B. Fat

C. Glucose

D. Fructose

Answer: B

70. Number of ATP produced from one pyruvic acid during conversion of acetyl CoA is _____

A. 5

B. 10

C. 3

D. 1

Answer: C

71. During aerobic respiration net number of water molecules produced per molecule of glucose is ______

A. 6

B. 5

C. 4

D. 8

Answer: A

72. Net ATP molecules formed in glycolysis is ______

A. 38

B. 12

C. 2

D. 1

Answer: C

73. One NADH2 produce number of ATP is ______

A. 6 ATP

B. 1 ATP

C. 38 ATP

D. 3 ATP

Answer: D

74. Glycolysis takes place in cytoplasm and the end product is ______

A. Pyruvic acid

B. Oxylic acid

C. Glucose

D. 30 ATP

Answer: A

75. Calvin cycle is reductive carboxylation and final product of this cycle is ______

A. Pyruvic acid

B. Phosphoglycer-aldehyde

C. Phosphoglyceric acid

D. Both A and B

Answer: B

76. TCA cycle occur in mitochondria and intermediate between glycolysis and TCA cycle is _____

A. Oxaloacetate

B. Pyruvic acid

C. Acetyl-Co A

D. Both A and B

Answer: C

77. The net gain of energy from one molecule of sucrose in aerobic respiration is ______

A. 38 ATP

B. 76 ATP

C. 37 ATP

D. 79 ATP

Answer: B

78. The net gain of energy from one gram mole of glucose during aerobic respiration is _____

A. 36 ATP

B. 42 ATP

C. 38 ATP

D. 40 ATP

Answer: C

79. When 4 molecules of phosphoglyceraldehyde are converted into 4 molecules of pyruvate than how many molecules of NADH are produced

A. 2

B. 7

C. 4

D. 8

Answer: C

80. Cytochromes help in plant growth, which is reacts with O2 in electron transport system

A. Cyt. a3

B. Cyt. b3

C. Cyt. c3

D. Cytf

Answer: A

81. Common precursor in CAM, UMP and TMP is ________

A. Aspartate

B. Glutamine

C. Glutamate

D. Adenosine

Answer: A

82. To fix 1 molecule of N 12 ATP molecule are required and N fixation is carried out by the enzyme

A. Nitrogenase and Rubisco

C. Nitrite reductase only

B. Nitrogenase only

D. Nitrate reductase

Answer: B

83. The natural occurring in higher plant is ­­­­­_________

A. IAA

B. IBA

C. NAA

D. IBA and NAA

Answer: A

84. Dwarfness of the plant can be control by _____

A. IAA

B. MH

C. GA

D. IBA

Answer: C

85. Polar translocation of plant hormone found in ______

A. Auxin

B. GA

C. Cytokinin

D. Zeatin

Answer: A

86. An essential growth substance required in tissue culture and delay the chlorophyll loss

A. GA

B. Kinetin

C. Cytokinin

D. Auxin

Answer: C

87. Tress hormone is ______

A. GA

B. IAA

C. ABA

D. Both A and B

Answer: C

88. Flowering of short day and long day plant is promoted by ________

A. IAA and GA respectively

B. GA only

C. Cytokinin and GA respectively

D. Kinetin and GA respectively

Answer: C

89. Chemitropism is _______

A. Growth of pollen tube toward ovule

B. Growth of pollen tube stigma to ovary

C. Movement of anthrozoids

D. Both A and B

Answer: A

90. Hormone involve in phototropism is _________

A. IAA

B. GA

C. Kinetin

D. Cytokinin

Answer: A

Plant Physiology Objective Questions with Answers Quiz Test Pdf Download

Leave a Reply

Your email address will not be published. Required fields are marked *