Photosynthesis Questions and Answers

1. With reference to factors affecting the rate of photosynthesis, which of the following statement is not correct?
A. Light saturation for CO2 fixation occurs a 10% of full sunlight.
B. Increasing atmospheric CO2 concentration up to 0.05% can enhance CO2 fixation rate.
C. C3 plants respond to higher temperature with enhance photosynthesis while C4 plants have much lower temperature optimum.
D. Tomato is a greenhouse crop which can be grown in CO2 – enriched atmosphere for higher yield.

2. Phosphoenol pyruvate (PEP) is the primary CO2 acceptor in-
A. C3 plants
B. C4 plants
C. C2 plants
D. C3 and C4 plants

3. The process which makes major difference between C3 and C4 plants is-
A. Calvin cycle
B. Glycolysis
C. Photorespiration
D. Respiration

4. A plant in your garden avoids photorespiratory losses, has improved water use efficiency, shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilisation. In which of the following physiological group would you assign this plant?
A. Nitrogen fixer
B. CAM
C. C4
D. C3

5. Emerson’s enhancement effect and Red drop have been instrumental in the discovery of-
A. Two photosystems operating simultaneously
B. Photophosphorylation and non-cyclic electron transport.
C. Oxidative phosphorylation
D. Photophosphorylation and cyclic electron transport.

6. In a chloroplast the highest number of protons are found in-
A. Antennae complex
B. Intermembrane space
C. lumen of thylakoids
D. stroma

7. Assertion : CAM plants lack structural compartmentation of leaf as found in C4 plants.
Reason : Stomata of CAM plants are open during the day.
A. Both assertion and reason are true and reason is the correct explanation of assertion.
B. Both assertion and reason are true but reason is not the correct explanation of assertion.
C. Assertion is true but reason is false.
D. Both assertion and reason are false

8. Photosynthesis in C4 plants is relatively less limited by atmospheric CO, levels because
A. there is effective pumping of CO2 into bundle sheath cells.
B. RuBisCO in C4 plants has higher affinity for CO2
C. six carbon acids are the primary initial CO2 fixation products
D. the primary fixation of CO2 is mediated via PEP carboxylase.

9. Splitting of water molecules during the light reaction of photosynthesis is associated with-
A. PS-I resulting in the release of O2, protons and transfer of electrons to PS-II
B. PS-II resulting in the release of O2, protons and transfer of electrons to PS-I
C. PS-II resulting in the release of O2, protons and transfer of electrons to PS-II
D. PS-I resulting in the release of O2, protons and transfer of electrons to PS-I
A. A alone is correct
B. B alone is correct
C. C alone is correct
D. D alone is correct

10. Kranz anatomy is not seen in-
(i) Maize
(ii) Sorghum,
(iii) Tomato.
A. (i) & (ii) only
B. (i) only
C. (i) & (ii) only
D. (iii) only

11. In Photorespiration, the number of ATP and NADPH synthesised are respectively-
A. 1 and 3
B. 2 and 3
C. 3 and 4
D. 0 and 0

12. A Plant is provided with ideal conditions for photosynthesis and supplied with isotope 14CO2. When the products of the process are analysed carefully, what would be the nature of products?
A. Both glucose and oxygen are normal
B. Both glucose and oxygen are labeled
C. Only glucose is labelled and oxygen is normal
D. Only oxygen is labelled but glucose is normal

13. The first carbon dioxide fixation product of C4 plants is-
A. Oxaloacetic acid
B. Ribulose biphosphate
C. Phosphoenol Pyruvate
D. Phosphoglyceric acid.

14. Carbon dioxide is necessary for photosynthesis. The chemical used to remove this gas most effectively from entering a control apparatus is-
A. Calcium oxide
B. Distilled water
C. Potassium hydroxide solution
D. Sodium carbonate.

15. Assertion : In light reaction of photosynthesis light is required for the functioning of PS-I and PS-II and production of NADPH and ATP.
Reason : Dark reaction does not occur in light.
A. Both assertion and reason are true and reason is the correct explanation of assertion.
B. Both assertion and reason are true but reason is not the correct explanation of assertion.
C. Assertion is true but reason is false.
D. Both assertion and reason are false.

16. In photosynthesis, the light independent reaction take place at-
A. stromal matrix
B. thylakoid lumen
C. photosystem I
D. photosystem II

17. Chromatophores take part in-
A. Movement
B. Photosynthesis
C. Growth
D. respiration

18. C4 pathway is advantageous over C3 pathway in plants as it-
A. occurs in relatively low CO2 concentration
B. used more about of water
C. occurs in relativety low O2, concentration
D. is less efficient in energy utilisation

19. Maximum absorption of light by chlorophyll- a occurs in which regions of the absorption specturm?
A. Blue
B. Red
C. Green
D. Yellow
A. B and C only
B. B and D only
C. A and B only
D. A and D only

20. Cycil-photophosphorylation results in the formation of-
A. NADPH + H+
B. ADP
C. ATP and NADPH + H+
D. ATP.

21. 3-phosphoglyceric acid (PGA) as the first CO2 fixation product is algal photosynthesis was discovered by-
A. Joseph Priestley
B. Jan Ingenhousz
C. T.W. Engelmann
D. Melvin Calvin

22. An example of CAM plant is-
A. Black nightshade (Solanum nigrum)
B. Lemon grass (Gymbopogen flexuosus)
C. Sugarbeet (Beta vulgaris)
D. Snake plant (Sanseviera trifaciata)

23. During photosynthesis plants-
A. absorb O2, release CO2
B. release O2, absorb CO2
C. absorb N2, release O2
D. absorb N2, release NH3

24. The element essential for evolution of oxygen during photosynthesis is-
A. Mg
B. Mn
C. Fe
D. Mo

25. Which ion is Constituent of chlorophyll?
A. Fe++
B. Fe+++
C. Mg++
D. Cu+

26. The central, structural atom in the primary photosynthesis pigment is-
A. Fe
B. Mg
C. Cu
D. Zn

27. The process of photosynthesis is-
A. reductive, exergonic and catabolic
B. reductive, endergonic and catabolic
C. reductive, exergonic and anabolic
D. reductive, endergonic and anabolic

28. Who amongst the following proposed the law of limiting factors?
A. Blackman
B. W.M. Stanley
C. M. Calvin
D. David Tilman

29. In C3 plants the first stable compound formed after CO2 fixation is-
A. oxaloacetic acid
B. malic acid
C. phosphoglyceraldehyde
D. 3-phosphoglycerate

30. The enzyme responsible for primary carboxylation in C3 plants is-
A. pyruvate carboxylase
B. succinic dehydrogenase
C. hexokinase
D. RUBP carboxylase oxygenase

31. Number of ATP molecules 8 molecules of water due to non-cyclic electron transport and subsequent photophosphorylation is-
A. 16
B. 8
C. 4
D. 12

32. Choose the correct statement-
A. Stroma lamella membrane lacks PS II and PS I.
B. When PS I is functional, electron flow in a non-cyclic way.
C. ATPase enzyme consist of F0 and F1 units.
D. NADP reductase is a part of PS II.

33. Time taken from fixation of CO2 to the formation of one glucose molecule is about ______ sec.
A. 20
B. 40
C. 60
D. 90

34. Which one of the following is a CAM plant-
A. Maize
B. Sugarcane
C. Kalanchoe
D. Jowar

35. Mn, Ca and Cl present in PS II play an important role in-
A. Absorption of light
B. CO2 assimilation
C. Photolysis of water
D. ATP synthesis.

36. Visible portion of light spectrum useful in photosynthesis is referred to as-
A. RFLP
B. PAR
C. VAM
D. VNTR

37. Anoxygenic photosynthesis is characteristic of-
A. Rhodospirillum
B. Spirogyra
C. Chlamydomonas
D. Ulva

38. Chlorophyll molecules are located in the-
A. thylakoid membrane
B. thylakoid lumen
C. stroma
D. inner chloroplast membrane

39. The correct sequence of organelles in which glycolate and sequentially in photorespiration is-
A. chloroplast and mitochondria
B. chloroplast and peroxisome
C. peroxisome and mitochondria
D. peroxisome and chloroplast

40. Which of the following statements regarding cyclic flow of electrons during light reactions is false?
A. This process takes place in the stromal lamella.
B. ATP synthesis takes place.
C. NADPH + H+ is synthesized.
D. Takes place only when light of wavelength beyond 680 nm is available for excitation.

41. Which of the following statement is correct?
A. The core of cilium or flagellum is the basal body.
B. Elaioplasts store starch whereas aleuroplasts store proteins.
C. Membranous extensions into the cytoplasm in cyanobacteria which contain pigments are called chromatophores.
D. Acrocentric chromosomes have only one arm.

42. Statement A : Photorespiration decreases photosynthetic output.
Statement B : In photorespiratory pathway, neither ATP nor NADPH is produced.
A. Statement A is correct and statement B is wrong.
B. Both the statements A and B are correct.
C. Statement B is correct and statement A is wrong.
D. Both the statements A and B are wrong.

43. In PS I the reaction centre chlorophyll a has an absorption peak at-
A. 650 nm
B. 660 nm
C. 700 nm
D. 680 nm

44. PAR stands for
A. Photosynthetically Adaptable Radiation.
B. Photosynthetically Accessible Radiation.
C. Photosynthetic Activity Radiometry.
D. Photosynthetically Active Radiation.

45. In purple and green bacteria, oxygen is not evolved during photosynthesis because hydrogen donor is-
A. H20
B. H2S
C. NH3
D. CH4

46. The idea of two pigment systems in light reaction of photosynthesis was given by-
A. Arnon
B. Hill
C. Blackman
D. None of the above

47. C4 plants have bundle sheath cells which possess
A. few chloroplasts with thin walls so that gaseous exchange can take place
B. large number of chlotoplasts with thick walls impervious to gaseous exchange
C. large number of chloroplasts and intercellular spaces
D. few chloroplasts with thick walls and no intercellular spaces

48. To produce one molecule of glucose Calvin cycle turns
A. 4 times
B. 2 times
C. 8 times
D. 6 times

49. Which one of the following statements about the events of non-cyclic photophosphorylation is not correct?
A. Only one photosystem participates
B. ATP and NADPH are produced
C. Photolysis of water takes place
D. O2 is released.

50. Oxygen evolution is connected with
A. Photosystem I
B. Photosystem II
C. Cyclic photophosphorylation
D. RUBP enzyme.