Photosynthesis
Multiple Choice Questions and Answers
1. Photorespiration is a phenomenon that occurs in the cycle
(a) Pyruvate
(b) Glycolate
(c) Hill
(d) Krebs
Answer: (b) Glycolate
2. The energy wastage occurs during
(a) dark reaction
(b) photorespiration
(c) photosynthesis
(d) none of the above
Answer: (b) photorespiration
3. Oxygen liberated during photosynthesis comes from
(a) carbondioxide
(b) water
(c) phosphoglyceric acid
(d) chlorophyll
Answer: (b) water
4. The first step in photosynthesis is
(a) joining of three carbon atoms to form glucose
(b) formation of ATP
(c) ionization of water
(d) excitement of an electron of chlorophyll a by a photon of light
Answer: (d) excitement of an electron of chlorophyll a by a photon of light
5. Dark reaction in photosynthesis is called so because
(a) it can also occur in dark
(b) it does not require light energy
(c) neither of these
(d) both of these
Answer: (b) it does not require light energy
6. During photosynthesis oxygen in a glucose comes from
(a) water
(b) carbon dioxide
(c) both water and carbon dioxide
(d) from air
Answer: (b) carbon dioxide
7. Haeme is constituent of one type of electron transport substance
(a) hemoglobin
(b) phytochrome
(c) cytochrome
(d) NADP
Answer: (c) cytochrome
8. All photosynthetic green plants contain
(a) chlorophyll a
(b) chlorophyll b
(c) chlorophyll c
(d) chlorophyll d
Answer: (a) chlorophyll a
9. First stable product of carbon assimilation is
(a) phosphoglycerate
(b) glucose
(c) starch
(d) pyruvic acid
Answer: (a) phosphoglycerate
10. Kranz anatomy is found in
(a) C4 plants
(b) C3 plants
(c) succulents
(d) none of the above
Answer: (a) C4 plants
11. Chlorophyll a is characterized by the side group of
(a) methyl
(b) aldehyde
(c) phytol
(d) keto
Answer: (a) methyl
12. Ferredoxin is a component of
(a) P680
(b) Hill reaction
(c) photosystem II
(d) photosystem 1
Answer: (d) photosystem 1
13. Photorespiration is favoured by
(a) low light intensity
(b) low oxygen and high carbon dioxide
(c) low temperatures
(d) high oxygen and low carbon dioxide
Answer: (d) high oxygen and low carbon dioxide
14. In C4 plants initial acceptor of carbon dioxide is
(a) ribulose 5 phosphate
(b) phosphoenolpyruvic acid
(c) ribulose 1-4 diphosphate
(d) 3PGA
Answer: (b) phosphoenolpyruvic acid
15. For each molecule of glucose formed in plants, the number of molecules of ATP and NADPH2 required are respectively
(a) 15 and 10
(b) 12 and 18
(c) 18 and 12
(d) 33 and 22
Answer: (c) 18 and 12
16. Of the following photosynthesizing organisms chlorophyll a is absent in
(a) bacteria
(b) flowering plants
(c) herbs
(d) algae
Answer: (a) bacteria
17. The percentage of light energy fixed in photosynthesis is generally around
(a) 35%
(b) 10%
(c) 50%
(d) 1%
Answer: (d) 1%
18. The inner envelope of chloroplast is permeable to
(a) triose phosphate
(b) orthophosphate
(c) sucrose
(d) glutamine
Answer: (b) orthophosphate
19. Which of the following photosynthetic bacteria have both PSI and PSII?
(a) green sulphur bacteria
(b) purple sulphur bacteria
(c) purple non sulphur bacteria
(d) cyanobacteria
Answer: (d) cyanobacteria
20. Ribulose diphosphate carboxylase oxygenase is located in
(a) mitochondria
(b) chloroplast
(c) peroxisomes
(d) golgi bodies
Answer: (b) chloroplast
21. There are two light reactions in photosynthesis. The one sensitive to longer wavelength of light is known as
(a) photosystem I
(b) photosystem II
(c) photophosphorylation
(d) photolysis
Answer: (a) photosystem I
22. Photorespiration is characteristic of
(a) C3 plants
(b) C4 plants
(c) CAM plants
(d) none of the above
Answer: (b) C4 plants
23. First stable product of dark reaction in C3 plants is
(a) PGA
(b) RuBP
(c) PEP
(d) OAA
Answer: (a) PGA
24. Photosynthesis is a process in which
(a) carbon dioxide is reduced to carbohydrate
(b) NADH is reduced to NAD
(c) ATP is generated
(d) oxidative phosphorylation occurs
Answer: (a) carbon dioxide is reduced to carbohydrate
25. Photolysis of water is associated with
(a) PSI
(b) PSII
(c) cytochrome b
(d) quinone
Answer: (b) PSII
26. Photorespiration occurs in
(a) C3 plants
(b) C4 plants
(c) all plants
(d) algae only
Answer: (b) C4 plants
27. Carbon dioxide fixation during C4 pathway occurs in the chloroplast of
(a) guard cells
(b) mesophyll cells
(c) spongy parenchyma
(d) bundle sheath cells
Answer: (d) bundle sheath cells
28. Structural component of chlorophyll among the following is
(a) magnesium
(b) manganese
(c) zinc
(d) iron
Answer: (a) magnesium
29. Calvin cycle is
(a) not dependent on light
(b) inhibited by light
(c) partly dependent on light
(d) dependent on light
Answer: (a) not dependent on light
30. Fructose 1-6 biphosphate splits into two triose phosphates by the enzyme
(a) amylase
(b) ligase
(c) aldolase
(d) zymase
Answer: (c) aldolase
31. C4 cycle is present in
(a) rice
(b) sugarcane
(c) pea
(d) Funaria
Answer: (b) sugarcane
32. What will be the number of Calvin cycles required to generate one molecule of hexose?
(a) 4
(b) 6
(c) 8
(d) 9
Answer: (b) 6
33. One quantasome contains
(a) 230 chlorophyll molecules
(b) 233 chlorophyll molecule
(c) 330 chlorophyll molecules
(d) a few molecules of chlorophyll
Answer: (a) 230 chlorophyll molecules
34. PEP is carbon dioxide acceptor in
(a) C3 plants
(b) Lichens
(c) C4 plants
(d) Hydrilla
Answer: (c) C4 plants
35. What happens in photosystem II?
(a) carbon dioxide fixation
(b) carbon dioxide reduction
(c) photolysis of water
(d) all of the above
Answer: (a) carbon dioxide fixation
36. The C4 plants are more efficient than C3 plants because
(a) they have two types of chloroplasts
(b) carbon dioxide acceptor in them is PEP
(c) they lack photorespiration
(d) none of these
Answer: (c) they lack photorespiration
37. The rate of photosynthesis per unit of light energy would be more in
(a) continuous bright light
(b) continuous dull light
(c) intermittent light
(d) normal blue light
Answer: (c) intermittent light
38. The site of dark reaction in photosynthesis is
(a) grana
(b) cytoplasm
(c) stroma
(d) thylakoid
Answer: (c) stroma
39. Which one does not evolve oxygen?
(a) green algae
(b) blue green algae
(c) autotrophic plants
(d) photosynthetic bacteria
Answer: (d) photosynthetic bacteria
40. Malic acid is found in C4 plants in the cells of
(a) epidermis
(b) bundle sheath
(c) phloem
(d) mesophyll
Answer: (d) mesophyll
41. Hatch and slack pathway is also known as
(a) C3 cycle
(b) C4 cycle
(c) C2 cycle
(d) none of these
Answer: (b) C4 cycle
42. Electrons from excited chlorophyll of PSII are accepted first by
(a) Quinone
(b) Ferredoxin
(c) cytochrome b
(d) cytochrome f
Answer: (a) Quinone
43. The law of limiting factors was proposed by
(a) F.F.Blackman
(b) D.Arnon
(c) Robert Hill
(d) R. Emmersion
Answer: (a) F.F.Blackman
44. Rate of photosynthesis is maximum in
(a) red and blue light
(b) blue and yellow light
(c) green light
(d) white light
Answer: (a) red and blue light
45. Photorespiration in C3 plants starts from
(a) phosphoglycerate
(b) phosphoglycolate
(c) glycerate
(d) glycine
Answer: (b) phosphoglycolate
46. A molecule of sedoheptulose has carbon atoms numbering
(a) 2
(b) 4
(c) 6
(d) 7
Answer: (d) 7
47. Emmersion effect is associated with
(a) respiration
(b) salt absorption
(c) photosynthesis
(d) transpiration
Answer: (c) photosynthesis
48. Which of the following is concerned with photo respiration ?
(a) dictyosomes
(b) peroxisomes
(c) glyoxisomes
(d) ribosomes
Answer: (b) peroxisomes
49. Net gain of ATP molecules during aerobic respiration is
(a) 36 molecules
(b) 38 molecules
(c) 40 molecules
(d) 48 molecules
Answer: (a) 36 molecules
50. Which pigment system is inactivated in red drop
(a) PS1 and PSII
(b) PSI
(c) PSII
(d) none of these
Answer: (b) PSI
51. Which element is located at the centre of the porphyrin ring in chlorophyll?
(a) calcium
(b) magnesium
(c) potassium
(d) manganese
Answer: (b) magnesium
52. Stomata of CAM plants
(a) are always open
(b) open during the day and close at night
(c) open during the day and close during the day
(d) never open
Answer: (c) open during the day and close during the day