Botany Objective Multiple Choice Questions with Key

Following are objective multiple choice questions from Botany. These questions are useful for Intermediate Second Year students of AP Board. These are also useful for EAMCET, NEET, and other competitive examinations where Botany questions will be asked. Key / Answers also provided at the end of the questions.

1. The first step in photosynthesis is-
1) Joining of three carbon atoms to form glucose
2) Formation of ATP
3) Ionization of water
4) Excitement of an electron of chlorophyll by a photon of light

2. Our present day view regarding photosynthesis is that-
1) Converts light energy into chemical energy
2) Creates useful energy
3) Fixes CO2 into carbohydrates
4) Reverses the action of respiration

3. During photosynthesis the oxygen in glucose comes from
1) Water 2) Carbon dioxide
3) O2 in air 4) Both from water and CO2

4. Photosynthesis is most active in-
1) Sun light 2) Yellow light 3) Red light 4) Green light

5. Which one of the following pigment does not occur in the chloroplast?
1) Carotene 2) Xanthophyll 3) Chlorophyll ‘b’ 4) Anthocyanin

6. If the CO2 content of the atmosphere is as high as 300 parts per million.
1) All plants would be killed
2) The plants would not grow properly
3) Plants would grow for some time and then die
4) The plants would thrive well

7. The universal hydrogen acceptor is
1) NADP 2) ATP 3) CO-A 4) FMN

8. Photo phosphorylation is the process in which
1) CO2 and O2 unite
2) Phosphoglyceric acid is produced
3) Aspartic acid is formed
4) Light energy is converted into chemical energy by production of ATP

9. Algae and other submerged plants in water float during day time and sink at night, because
1) They come upto enjoy some time
2) They lose weight at night
3) They become byont due to accumulation of O2 as a result of photosynthesis
4) They become light due to food material accumulation

10. Which pigment is water soluble?
1) Chlorophyll 2) Carotene 3) Anthocyanin 4) Xanthophyll

11. Which occurs during the light reaction of photosynthesis?
1) Chlorophyll is produced 2) Water splits to form H2 and O2
3) CO2 is given off as a waste 4) Sugar is formed from CO2 and water

12. Chloroplasts fix-
1) Carbon dioxide 2) Oxygen 3) Nitrogen 4) Hydrogen

13. During the dark reactions of photosynthesis
1) Water splits
2) CO2 is reduced to organic compounds
3) Chlorophyll is activated
4) C6 – Suagar is broken into three carbon sugars

14. The isotope of carbon used extensively for studies in photosynthesis
1) C13 2) C14 3) C15 4) C16

15. What will be left if chlorophyll is burnt?
1) Magnesium 2) Manganese 3) Iron 4) Sulphur

16. In photosynthesis hydrogen is transferred from the light reactions to dark reactions by-
1) DPN 2) DNA 3) ATP 4) NADP

17. Solar energy is converted into ATP in-
1) Mitochondria 2) Chloroplast 3) Ribosomes 4) Peroxisomes

18. The enzyme that fixes atmspheric CO2 in C4 plants is-
1) PEP carboxylase 2) Hexokinase
3) RuBP oxygenase 4) Hydrogenase

19 The path of CO in the dark reactions of photosynthesis was successfully traced by the use of the following-
1) O2 18 2) C14 O2 3) P32 4) X-rays

20. Which one of the following have high CO2compensation point?
1) C2 plants 2) C3 plants 3) C4 plants 4) Alpine herbs

21. During photosynthesis when PGA is changed into phosphoglyceraldehyde which of the following reaction occur
1) Oxidation 2) Reduction 3) Electrolysis 4) Hydrolysis

22. Which one of the following is a C4 plant?
1) Papaya 2) Potato 3) Maize 4) Pea

23. Carbon refixation in C4 plants occurs in chloroplasts of-
1) Palisade tissue 2) Spongy Mesophyll
3) Bundle sheath cells 4) Gaurd cells

24. Tropical plants like sugar cane show high efficiency of CO2 fixation because of-
1) Calvin cycle 2) Hatch-Slack cycle
3) Cyclic photo phosphorylation 4) TCA Cycle

25. During photochemical reaction of photosynthesis
1) Liberation of O2 takes places
2) Formation of ATP and NANPH2 takes place
3) Liberation of O2, formation of ATP and NADPH2 takes place
4) Assimilation of CO2 takes place

26. The wave of light not utilized during photosynthesis is-
1) Violet 2) Green 3) Red 4) Blue

27. In blue-green alga photosynthesis takes place in-
1) Chloroplasts 2) Lamellae 3) Heterocysts 4) Carotene

28. Usually the process of photosynthesis is-
1) Slower than respiration 2) Faster than respiration
3) Equal to respiration 4) Any of the above is possible

29. Photosynthesis is maximum during-
1) Continous weak light 2) Continuous strong light
3) Intermittent light 4) None of the above

30 Th hi f d t f hill ti
1) ATP and NADPH2 in chloroplast
2) ATP and NADPH2 in mitochondria
3) Only Oxygen
4) A reduced substance ATP and O2 in chloroplast

31. Process of photo phosphorylation was first given by-
1) Hill 2) Will statter & Stoll
3) Arnon 4) Park & Biggins

32. Name the scientist who first pointed out that plants purify foul air-
1) Willsatter 2) Robert Hooke 3) Priestley 4) Lean Senebier

33. Of the total amount of water absorbed by the plant, its actual percentage used during photosynthesis is-
1) 50% 2) 90% 3) hardly 1% 4) 25%

34. Accumulation of food in assimilatory cells results in-
1) Increase in the rate of photosynthesis
2) Decrease in the rate of photosynthesis
3) No effect
4) May increase or decrease

35. Moll’s leaf experiement explains that
1) Carbon dioxide is essential for photosynthesis
2) Chlorophyll and water are necessary for photosynthesis
3) Light and water are esential for photosynthesis
4) All are correct

36. The chemical composition of pigments chlorophylls and carotenoids for the first time was given by-
1) Willistatter and stoll 2) Mayer and Anderson
3) Robert mayer 4) Senebier

37. Which colour of light gives maximum absorption peak by chlorophyll ‘a’?
1) Blue light 2) Green light 3) Violet light 4) Red light

38. The volume of CO2 absorbed and O2 liberated during photosynthesis is equal was demonstrated by39. That oxygen during photosynthesis comes from water was proved by-
1) Ruben and kamen 2) Hill 3) Warburg 4) Black man

40. The principle of limiting factor was given by-
1) Hill 2) F.F. Black man
3) Will statter and stoll 4) Calvin

41. The rate of photosynthesis decreases if the wavelength of visible light exceeds 680m. This was shown by which scientist & what is its reason
1) Black man – Law of limiting factors
2) Calvin & Benson – Photooxidation
3) Emerson & Levis – Red drop
4) Ruben & Ramen – Photolysis

42. During ionisation of H2O, H+ is captured by-
1) Chlorophyll 2) NADP 3) O2 4) Cytochrome

43. At the time of ionization of H2O, which captures the electron-
1) Chlorophyll 2) NADP 3) OH- 4) Cytochrome

44. In cyclic photo phosphorylation which one of the following is formed?
1) NADP & ATP 2) ATP
3) NADH2 and O2 4) NADPH2, ATP and O2

45. The most effective wavelength of visible light in photosynthesis in the region of which of the following:
1) Green 2) Yellow 3) Red 4) Violet

46. Which of the following photosynthesis bacteria have both PS I & PS II?
1) Purple sulphur bacteria 2) Cyanobacteria
3) Purple non sulphur bacteria 4) Green sulphur bacteria

47. The site of oxyten evolution and photosynthetic phosphorylation in chloroplast are..
1) Grana stacks 2) Matrix
3) Surface of chloroplast 4) inner wall of chloroplast

48. Fixation of 1 CO2 requires
1) 6 NADPH2 & 3ATP 2) 2 NADPH2 & 3ATP
3) 4 NADPH2 4) 5 NADPH2 & 3 ATP

49. Photosynthesis is mainly responsible for the existence of-
1) Animals of this earth 2) Plants on this earth
3) Both plants and animals 4) None of the above

50. The main difference between chlorophyll ‘a’ and ‘b’ is-
1) Chlorophyll ‘a’ is a linear chain compound and ‘b’ is branched chain
2) Chlorophyll ‘a’ has no Mg+ ion in center of molecule
3) In chlorophyll ‘a’ there is  CH3 group whereas in ‘b’ it is  CHO group
4) All of the above

51. For chlorophyll formation in plants elements needed are
1) Sodium and copper 2) Calcium and potassium
3) Iron and magnesium 4) Iron and calcium

52. Etiolated plants are formed due to lack of-
1) Light 2) Hg 3) Fe 4) Mg

53. Chloroplast contains maximum quantity of-
1) pyruvic carboxylase 2) Hexokinase
3) RuBP carboxylase 4) None of the above

54. Chlorophyll ‘a’ is found in-
1) All O2 releasing photosynthetic forms
2) All plants except fungi
3) Higher plants that photosynthesize
4) All photosynthetic prokaryotes and eukaryotes

55. Photo oxidation of water in photosynthesis is in association of-
1) Cytochrome B6 2) Pigment system – I
3) Pigment system – II 4) Plastocyanin

56. In pigment system – I active chlorophyll is-
1) P-600 2) P-680 3) P-700 4) P-720
57. During ATP synthesis electron pass through-
1) Water 2) Cytochromes 3) O2 4) CO2

58. Which of the following is C-4 plants?

59. “Kranz Anatomy” is found in-
1) Flower 2) Seed 3) Leaves 4) Stem

60. How many quanta are required to reduce one molecule of CO2 and produce one
molecule of O2 in green plant photosynthesis?
1) 1 2) 8 3) 16 4) 32

61. The function of ATP in the photosynthesis is the tranfer of energy from-
1) Dark reaction to light reaction 2) Light reaction to dark reaction
3) Chloroplast to mitochondria 4) Mitochondria to chloroplast

62. Respiration and photosynthesis both require-
1) Green cells 2) Sunlights 3) Cytochromes 4) Organic fuel

63. Photosynthesis is an oxidation reduction process, the materials that is oxidised is-
1) CO2 2) NADP 3) H2O 4) PGA

64. In case of C-4 pathway, in the first step is-
1) CO2 combines with RUDP 2) CO2 combines with PGA
3) CO2 combines with PEP 4) CO2 combines with RMP

65. Substrate for photorespiration is-
1) Serine 2) Glycolate 3) Indole acetic acid 4) Malic acid

66. Chlorophyll ‘e’ is generally present in-
1) Thallophytes 2) Rhodophytes
3) Mycophytes 4) Xanthophytes

67. The family in which many plants are C4 type-
1) Malvaceae 2) Solanaceae 3) Crucifereae 4) Gramine

68. In pigment system-II the entraping center of solar energy is-
1) P-700 2) P-680 3) Carotene 4) Xanthophyll

69. Which of the following is likely to be the first substance that a green plant makes in photosynthesis?
1) A simple sugar 2) Starch 3) Fats 4) Proteins

70. The by product of photosynthesis is-
1) CO2 2) Oxygen 3) Energy 4) Sugar

71. Photorespiration is favoured by-
1) Low light intensity 2) Low O and High CO
3) Low temperature 4) High O2 and Low CO2

72. Tropical plants like sugarcane show high efficiency of CO2 fixation because of-
1) Calvin cycle 2) Hatch & Slack cycle
3) EMP pathway 4) TCA cycle

73. The electron ejected by P680 in light reaction is initially accepted by-
1) Plastoquinone 2) ATP 3) Ferredoxin 4) P-700

74. What is photosynthesis quotient?
1) O2/CO2 2) CO2/O2 3) O2/starch 4) Water/ starch

75. What is the common value of PQ (Photosynthetic quotient) of a leaf?
1) > 1 2) < 1 3) One 4) Zero 76. What is the by product of bacterial photosynthesis? 1) O2 2) H2O 3) S 4) H2S 77. Photosynthesis bacteria do not contain- 1) PS I 2) PS II 3) PS I or PS II 4) Quantasome 78. In Cyanobacteria & Photosynthetic bacteria the photosynthesis takes place in- 1) Chloroplast 2) Chromoplast 3) Chromatophores 4) Mesosomes 79. CO2 is accepted by RuBP in C4 plants in- 1) Mesophyll cells 2) Bundle sheath cells 3) Stomatal gaurd cells 4) Epidermal cells 80. How many types of photosynthetic cells occur in C4 plant? 1) One type 2) Two types 3) Four types 4) eight types 81. Bundle sheath chloroplast of C4 plant are- 1) Large & agranal 2) Large & granal 3) Small & agranal 4) Small & granal 82. In C4 pathway the CO2 reduction occurs in- 1) Palisade tissue 2) Spongymesophyll 3) Bundle sheath 4) Gaurd cell 83. Synthesis of fructose in C4 pathway occurs in the chloroplast of- 1) Spongy mesophyll 2) Bundle sheath cells 84. What is C2 - Cycle? 1) Glycolate cycle 2) Calvin cycle 3) Kreb's cycle 4) TCA-Cycle 85. Rate of photosynthesis is more in the intermittent light due to the regeneration of 1) NADP 2) ATP 3) NADP & ATP 4) RuBP 86. Plants which exhibit photo respiration are 1) C4 plants 2) C3 plants 3) CAM plants 4) Alpine plants 87. Which of the following plants are low CO2 compensation plants →Thrive well even at low CO2 conc. 1) C3 − plants 2) C4-plants 3) C2-plants 4) Alpine plants 88. At the compensation point there will not be 1) Any photo synthesis 2) Any gaseous exchange between the plant and its environment 3) Any respiration in plants 4) Loss in weight of the plant in dark 89. Which of the following carries out non-oxygenic photo synthesis 1) Cyanobacteria 2) Crab grass 3) Bacteria 4) Wheat plant 90. In addition to the 12 molecules of NADP.H2 the energy required for the synthesis of one mole of hexose C3 and C4 pathway is 1) 18 molecules of ATP 2) 30 molecules of ATP 3) 18 & 30 molecules of ATP respectively 4) 30 & 18 molecules of ATP respectively 91. Pigment system-I is concerned with 1) Photolysis 2) Cyclic photophoshorylation 3) Non-Cyclic photosphorylation 4) Oxidation phosphorylation 92. What is the unique process which has supported life on this planet 1) N2 fixation 2) Photolysis 3) Protein synthesis 4) Respiration 93. During photo synthesis 1) Water is reduced & CO2 is oxidized 2) CO2 is reduced & water is oxidized 3) Both CO2 & water get reduced 4) Both CO2 & water get oxidized 94. Which element helps in the transport of electrons from water in photosynthesis 95. Cyclic photophosphorylation occurs in stroma thylakoids because 1) Lumen do not consists water 2) They have PS I only 3) NADP reductase and PS II are absent in them 4) 2 & 3 96. Calvin cycle occurs in 1) Mesophyll cells of C3 plants and bundle sheath cells of C4 plants 2) Mesophyll cells of C4 plants only 3) Bundle sheath cells of C3 plants and mesophyll cells of C plants 4) Bundle sheath cells of C4 plants only 97. The accessory pigments are 1) Chl b 2) Carotenoids 3) 1 & 2 4) Chl a, Chl b 98. The following inferred O2 evolved by the green plants comes from water and not from CO2 1) Hill 2) Calvin 3) Emerson 4) Neil 99. The colour of the leaf is due to 1) Chl a 2) Chl a & Chl b 3) Chl a, Chl b, Carotenoids 4) Chl a, carotenoids 100. In half leaf experiment CO2 is absorbed by 1) Mouse 2) KOH 3) Plant 4) Cotton KEY:

1-4; 2-1; 3-2; 4-1; 5-4; 6-4; 7-1; 8-4; 9-3; 10-3; 11-2; 12-1; 13-2; 14-2; 15-1; 16- 4; 17-2; 18-1; 19-2; 20-2; 21-2; 22-3; 23-3; 24-2; 25-3; 26-2; 27-2; 28-2; 29-3; 30-4; 31-3; 32-3; 33-3; 34-2; 35-1; 36-1; 37-1; 38-2; 39-1; 40-2; 41-3; 42-2; 43- 1; 44-2; 45-3; 46-2; 47-1; 48-2; 49-3; 50-3; 51-3; 52-1; 53-3; 54-1; 55-3; 56-3; 57-2; 58-4; 59-3; 60-2; 61-2; 62-3; 63-3; 64-3; 65-2; 66-4; 67-4; 68-2; 69-1; 70-
2; 71-4; 72-2; 73-1; 74-1; 75-3; 76-3; 77-2; 78-3; 79-2; 80-2; 81-1; 82-3; 83-2; 84-1; 85-3; 86-2; 87-2; 88-2; 89-3; 90-3; 91-2; 92-2; 93-2; 94-4; 95-4; 96-1; 97- 3; 98-4; 99-3; 100-2.