1. In \[C_{4}\] plants, \[CO_{2}\] combines with PEP in the presence of
a) PEP carboxylase
b) RuBP carboxylase
c) RuBP oxygenase
d) Hydrogenase
Explanation: PEP carboxylase
2. Dark reaction of photosynthesis is called so because it
a) Can also occur in dark
b) Does not require light energy
c) Cannot occur during day time
d) Occurs more rapidly at night
Explanation: Dark reaction of photosynthesis is called so because it does not require light energy.
3. The initial enzyme of Calvin cycle is
a) Ribulose 1, 5 diphosphate carboxylase
b) Triose phosphate dehydrogenase
c) Phosphofructokinase
d) Cytochrome oxidase
Explanation: The initial enzyme of Calvin cycle is Ribulose 1, 5 diphosphate carboxylase.
4. During photosynthesis, when PGA is changed into phosphoglyceraldehyde, which of the
following
reaction occurs?
a) Oxidation
b) Reduction
c) Electrolysis
d) Hydrolysis
Explanation: Reduction
5. Ribulose diphosphate carboxylase enzyme catalyses the carboxylation reaction between
a) Oxaloacetic acid and acetyl CoA
b) \[CO_{2}\] and ribulose 1, 5 diphosphate
c) Ribulose diphosphate and phosphoglyceraldehyde
d) PGA and dihydroxyacetone phosphate
Explanation: \[CO_{2}\] and ribulose 1, 5 diphosphate
6. Calvin cycle occurs in
a) Chloroplasts
b) Cytoplasm
c) Mitochondria
d) Glyoxysomes
Explanation: Calvin cycle occurs in chloroplasts.
7. In \[C_{3}\] plants, the first stable product of photosynthesis during dark reaction is
a) 3-phosphoglyceric acid
b) Phosphoglyceraldehyde
c) Maleic acid
d) Oxaloacetic acid
Explanation: 3-phosphoglyceric acid
8. How many Calvin cycle forms one hexose molecule?
a) 2
b) 6
c) 4
d) 8
Explanation: 6 calvin cycle forms one hexose molecule.
9. In which plant Calvin experimented the radioactive isotopy to discover the stable product of
\[C_{3}\] cycle?
a) Chlorella
b) Cycas
c) Carrot
d) Tobacco
Explanation: Chlorella
10. Mesophyll chloroplast of which plant alone is capable of synthesizing starch or sucrose?
a) \[C_{3}\] plant
b) \[C_{4}\] plant
c) Both (a) and (b)
d) Neither \[C_{3}\] nor \[C_{4}\]
Explanation: \[C_{3}\] plant
11. The enzymes of dark reaction in \[C_{4}\] plants are found in
a) Bundle sheath chloroplast
b) Mesophyll chloroplast
c) Both (a) and (b)
d) None of theses
Explanation: Both (a) and (b)
12. In \[C_{4}\] plants, the mesophyll cells are connected with bundle sheath cells with the help of
a) Cytoplasmic connection
b) Special connecting tissues
c) Plasmodesmata
d) Connection is not essential
Explanation: Plasmodesmata
13. In case of \[C_{4}\] pathway, \[CO_{2}\] combines with
a) PGA
b) PEP
c) RuDP
d) RMP
Explanation: In case of \[C_{4}\] pathway, \[CO_{2}\] combines with PEP
14. Which one is a \[C_{4}\] plant?
a) Papaya
b) Pea
c) Potato
d) Maize
Explanation: Maize is a \[C_{4}\] plant
15. \[C_{4}\] plants are also known as
a) Hatch and Slack type
b) Calvin type
c) Calvin and Bassham type
d) Emerson type
Explanation: \[C_{4}\] plants are also known as Hatch and Slack type.
16. In \[C_{4}\] plants, Calvin cycle occurs in
a) Stroma of bundle sheath chloroplast
b) Mesophyll chloroplast
c) Grana of bundle sheath chloroplast.
d) Does not occur as \[CO_{2}\] is fixed mainly by PEP and no \[CO_{2}\] is left for the Calvin cycle.
Explanation: Stroma of bundle sheath chloroplast
17. Tropical plant like sugarcane show high efficiency of \[CO_{2}\] fixation because of
a) Calvin cycle
b) Hatch and Slack cycle
c) EMP pathway
d) TCA cycle
Explanation: Tropical plant like sugarcane show high efficiency of \[CO_{2}\] fixation because of hatch and slack cycle.
18. Which of the following cycle shows oxaloacetic acid as the first stable product?
a) Calvin cycle
b) Hatch and Slack cycle
c) \[C_{2}\] cycle
d) None of theses
Explanation: Hatch and Slack cycle shows oxaloacetic acid as the first stable product
19. Kranz type of anatomy is found in
a) \[C_{2}\] plants
b) \[C_{3}\] plants
c) \[C_{4}\] plants
d) CAM plants
Explanation: Kranz type of anatomy is found in \[C_{4}\] plants.
20. \[C_{4}\] plants are adapted to
a) Hot and dry climate
b) Temperate climate
c) Cold and dry climate
d) Hot and humid climate
Explanation: \[C_{4}\] plants are adapted to hot and dry climate.
21. Which one of the following is wrong in relation to photorespiration?
a) It is a characteristic of \[C_{3}\] plants
b) It occurs in chloroplasts
c) It occurs in day time only
d) It is a characteristic of \[C_{4}\] plants
Explanation: It is a characteristic of \[C_{4}\] plants
22. How many types of photosynthetic cells occur in \[C_{4}\] plant?
a) One type
b) Two types
c) Four types
d) Eight types
Explanation: Two types
23. Which of the following cells of \[C_{4}\] plants are prominently loaded with starch?
a) Epidermal cells
b) Mesophyll cells
c) Bundle sheath cells
d) All of these
Explanation: Bundle sheath cells of \[C_{4}\] plants are prominently loaded with starch.
24. The number of carboxylation in \[C_{4}\] cycle is/are
a) 1
b) 2
c) 5
d) 3
Explanation: The number of carboxylation in \[C_{4}\] cycle is/are 2.
25.Photorespiration takes place in
a) Chloroplast, mitochondria
b) Mitochondria, peroxisome
c) Chloroplasts, peroxisome, mitochondria
d) Chloroplasts, cytoplasm, mitochondria
Explanation: Photorespiration takes place in chloroplasts, peroxisome, mitochondria.
26. Photorespiration is called
a) C2 cycle
b) \[C_{3}\] cycle
c) \[C_{4}\] cycle
d) None of theses
Explanation: Photorespiration is called C2 cycle.
27. The first reaction in photorespiraton is
a) Carboxylation
b) Decarboxylation
c) Oxygenation
d) Phosphorylation
Explanation: The first reaction in photorespiraton is Oxygenation.
28. \[C_{4}\] plant is characterized by
a) High tolerance to temperature
b) Lacks process of photorespiration
c) Greater productivity of biomass
d) All of these
Explanation: All of these
29. Bundle sheath cells have these following characters except
a) Large in size
b) Large number of chloroplast
c) Thick wall impervious to gaseous exchange
d) With intercellular spaces
Explanation: With intercellular spaces
30. Primary \[CO_{2}\] acceptor in \[C_{4}\] plant occurs in
a) Inner layer cells of bundle sheath
b) Outer layer cells of bundle sheath
c) Mesophyll cells
d) None of theses
Explanation: Primary \[CO_{2}\] acceptor in \[C_{4}\] plant occurs in mesophyll cells.
31. Bundle sheath cells are rich in
a) RuBisCO
b) PEP case
c) Both (a) and (b)
d) None of theses
Explanation: Bundle sheath cells are rich in RuBisCO.
32. Which of the following is correct about photorespiration?
a) Wasteful process
b) ATP is utilized
c) Release of \[CO_{2}\]
d) All of these
Explanation: All of these
33. During photorespiration
a) RuBisCo binds with \[O_{2}\]
b) Phosphoglycerate and phosphoglycolate is formed
c) Sugar is not synthesized
d) All the above
Explanation: All the above
34. Photorespiration does not takes place in \[C_{4}\] plant because
a) \[O_{2}\] is not released in \[C_{4}\] plant during photosynthesis.
b) Intracellular concentration of \[CO_{2}\] is high in bundle sheath and it ensures RuBisCo
function as carboxylase.
c) They are found in cold environment.
d) Stomata in them opens during night.
Explanation: Photorespiration does not takes place in \[C_{4}\] plant because intracellular concentration of \[CO_{2}\] is high in bundle sheath and it ensures RuBisCo function as carboxylase.
35.External factor affecting photosynthesis are
a) Sunlight and temperature
b) \[CO_{2}\] concentration
c) Water
d) All of these
Explanation: All of these
36. Internal factor affecting photosynthesis are
a) Number and size of leaf
b) Age of leaf and orientation
c) Internal \[CO_{2}\] concentration and amount of chlorophyll
d) All the above
Explanation: All the above
37. Internal factor of plant depends on
a) Growth of plant
b) Genetic predisposition
c) Both (a) and (b)
d) None of theses
Explanation: Internal factor of plant depends on both growth of plant and genetic predisposition.
38. Which is a limiting factor?
a) Green leaf
b) Optimal light
c) Optimal \[CO_{2}\]
d) Low temperature
Explanation: Low temperature
39. Photosynthesis is affected by
a) Quality of light
b) Intensity of light
c) Duration of light
d) All of these
Explanation: All of these
40. Light saturation occurs at _______ of the fall sunlight.
a) 2%
b) 5%
c) 10%
d) 20%
Explanation: Light saturation occurs at 10% of the fall sunlight.
41. Light may be a limiting factor for
a) plants in dense forest
b) plant in temperate forest
c) plant in grassland
d) all
Explanation: plants in dense forest
42. What is the relationship between \[CO_{2}\] fixation and incident light at low intensities?
a) Linear
b) Parabola
c) Hyperbola
d) None
Explanation: Linear relationship
43. Select the incorrect statement from the following:
a) At high intensities, both \[C_{3}\] and \[C_{4}\] plants shows increase in the rate of photosynthesis by
increasing \[CO_{2}\] concentration
b) \[C_{4}\] plants shows saturation at 360 μl/L.
c) \[C_{3}\] plant shows saturation beyond 450 μl/L.
d) Productivity of tomatoes and ball papers cannot be increased by enriching environment
by \[CO_{2}\] .
Explanation: "Productivity of tomatoes and ball papers cannot be increased by enriching environment by \[CO_{2}\]". This is incorrect statement.
44. Select the incorrect statement from the following:
a) Dark reaction is more sensitive to temperature.
b) Light reaction is less sensitive to temperature.
c) \[C_{4}\] plant responds to higher temperature and \[C_{3}\] plant have lower optimum temperature.
d) Tropical plant have lower optimum temperature for photosynthesis.
Explanation: "Tropical plant have lower optimum temperature for photosynthesis". This is incorrect statement.
45. Water stress leads to
a) Closing of stomata
b) Wilting of leaves
c) Reduced activity of leaf
d) All of these
Explanation: All of these
46. Which factor indirectly affects the process of photosynthesis?
a) Light
b) Temperature
c) \[CO_{2}\] concentration
d) Water
Explanation: Water
47. Photosynthesis takes place
a) Only in sunlight
b) Only in yellow light
c) In the visible light obtained from any source
d) Only in very high intensity of light
Explanation: Photosynthesis takes place in the visible light obtained from any source.
48. Photo-oxidation of chlorophyll is called
a) Intensification
b) Chlorosis
c) Solarization
d) Defoliation
Explanation: Photo-oxidation of chlorophyll is called Solarization.
49. Which one of the following is not a limiting factor for photosynthesis?
a) Oxygen
b) Carbon dioxide
c) Chlorophyll
d) Light
Explanation: Oxygen is not a limiting factor for photosynthesis
50. If a plant is kept in 300 ppm \[CO_{2}\] concentration, what will happen to it?
a) The plant will die soon.
b) The plant will grow but will not die.
c) The plant will show normal photosynthesis.
d) Respiration will be greatly decreased.
Explanation: The plant will show normal photosynthesis.