Physiology of Plants MCQs Part II

1) When succinate is oxidised in Krebs cycle, its hydrogen is accepted

b) FAD
c) FMN
d) Fumarate

2) The mineral activator of the enzyme aconitase is
a) Mn
b) Mg
c) Fe
d) Cu

3) Terminal oxidation comprises the
a) Synthesis of metabolic water
b) Electron transport
c) Oxidative phosphorylation
d) All the above

4) The formation of ATP in respiration is called
a) Photophosphorylation
b) Substrate phosphorylation
c) Oxidative phosphorylation
d) Phosphorylation

5) Electron acceptors in ETS are arranged according to their
a) Decreasing positive potential
b) Increasing positive potential
c) Increasing negative potential
d) None of the above

6) When a pair of electrons from
is transported through respiratory ETS, it results in the formation

a) 2 mol. of ATP
b) 4 mol. of ATP
c) 3 mol. of ATP
d) 5 mol. of ATP

7) Two molecules of ATP are formed during final oxidation of

8) In aerobic respiration, which of the following is a reactant?
d) Sugars

9) In the electron transport chain, the energy for ATP synthesis is produced
when electrons pass between

d) All the above

10) What is true for respiration?
a) Oxygen is essential
b) oxygen combines with carbon to form carbon dioxide
c) Oxygen combines with hydrogen to produce water
d) Oxygen is not essential

11) In respiration, the final acceptor of protons is
b) Oxygen
c) FAD
d) UQ

12) Oxygen required for terminal oxidation enters the mitochondria as
a) Glucose
b) Activated acetic group
c) Oxygen gas
d) Pyruvic acid

13) In respiration, most of the ATP is synthesised during
a) Electron transport
b) Glycolysis
c) Krebs cycle
d) Oxidation of pyruvate

14) The correct equation for aerobic respiration is

15) The cytochrome which hands over electrons to oxygen during terminal
oxidation is

a) Cyt b
b) Cyt a
c) Cyt c

16) Anaerobic respiration is
a) Complete oxidation
b) Incomplete oxidation
c) Anabolic reaction
d) Fermentation

17) An important requirement of fermentation is
a) Oxygen
b) Zymase
c) Fe

18) Which type of fermentation is accompanied by evolution?
a) Alcoholic fermentation
b) Lactic acid fermentation
c) Both A and B
d) None of the above

19) The respiratory intermediate which undergoes fermentation is

a) Glyceraldehyde 3-phosphate
b) 2-phosphoglyceric acid
c) PEP
d) Pyruvic acid

20) A characteristic feature of the ripening of some fruits is a sudden
increase in respiration. It is known as

a) Climacteric
b) Anthesis
c) Climatic
d) Photorespiration

21) Respiration is accompanied by a/an
a) Increase in weight
b) Decrease in weight
c) No change in weight
d) Decrease in size

22) Fruits kept in the refrigerator maintain their flavour and taste
for a longer period due to the

a) Nonavailability of oxygen
c) Presence of excess moisture
d) Slowing down of respiration

23) The rate of respiration
a) Increases with rise in temperature
b) Decreases in the presence of light
c) Increases in winter
d) Does not change with season and environmental conditions.

24) A bottle containing germinating seeds is connected to a
tube containing lime water. After some time, the lime water turns

a) Red
b) Brown
c) Green
d) Cloudy white

25) Providing oxygen to anaerobically respiring structures leads

a) Decreased ATP synthesis
b) Excess consumption of respiratory substrate
c) Hexose monophosphate shunt
d) More ATP synthesis in mitochondria

26) Wounding results in
a) Stoppage of growth
b) Infection
c) Decreased rate of respiration
d) Increased rate of respiration

27) In anaerobic respiration in plants
a) Oxygen is absorbed
b) Oxygen is released
c) Carbon dioxide is released
d) Carbon dioxide is absorbed

28) ATP synthesis occurs on the
a) Outer membrane of the mitochondrion
b) Inner membrane of the mitochondrion
c) Matrix
d) None of the above

29) The energy currency (reservoir) of the cells is
a) AMP
b) ATP
c) RNA
d) DNA

30) The other name of glycolysis is
a) EMP pathway
b) TCA pathway
c) HMS pathway
d) Carbon pathway

31) The incomplete oxidation of glucose into pyruvic acid with several intermediate steps is known as
a) TCA-pathway
b) Glycolysis
c) HMS-pathway
d) Krebs cycle

32) The number of molecules of pyruvic acid formed from one molecule of glucose at the end of glycolysis is
a) 1
b) 2
c) 3
d) 4

33) When a molecule of pyruvic acid is subjected to anaerobic oxidation and forms lactic acid, there is
a) Loss of 3 ATP molecules
b) Loss of 6 ATP molecules
c) Gain of 2 ATP molecules
d) Gain of 4 ATP molecules

34) The enzyme which converts glucose to glucose 6-phosphate is
a) Phosphorylase
b) Glucose-6-phosphatse
c) Hexokinase
d) Glucose synthetase

35) Pyruvic dehydrogenase is used in converting
a) Pyruvic acid to acetyl co-enzyme A
b) Pyruvate to glucose
c) Glucose to pyruvate
d) Pyruvic acid to lactic acid

36) The conversion of pyruvic acid into ethyl alcohol is facilitated by the enzyme
a) Decarboxylase
b) Dehydrogenase
c) Decarboxylase and dehydrogenase
d) Phosphatase

37) R.Q. for fatty substances/fats is
a) Unity
b) Less than one
c) Greater than one
d) Zero

38) R.Q. for glucose/carbohydrates is
a) 1
b) 0.5
c) 2
d) 0.05

39) An indispensable role in energy metabolism is played by
a) Sodium
b) Phosphorus
c) Calcium
d) Lithium

40) The amount of energy given by one mole of ATP is
a) 7.3 kcal
b) 721 kcal
c) 7600 kcal
d) 1000 kcal

41) Krebs cycle starts with the formation of a six-carbon compound by reaction between
a) Malic acid and acetyl CoA
b) Succinic acid and pyruvic acid
c) Fumaric acid and pyruvic acid
d) Oxalo-acetic acid and acetyl CoA.

42) Most of the energy in the cells is liberated by oxidation of carbohydrates when
a) Pyruvic acid is converted into CO2 and H2O
b) Pyruvic acid is converted into acetyl CoA
c) Sugar is converted into pyruvic acid
d) Glucose is converted into alcohol and carbon dioxide

43) In respiration the released energy is mainly stored in the form of
a) ADP
b) ATP
c) AMP
d) Glucose

44) The common immediate source of energy in cellular activity is
a) DNA
b) ATP
c) RNA
d) NAD

45) ATP is
a) An enzyme which brings about oxidation
b) A hormone
c) A protein
d) A molecule which contains high energy phosphate bonds

46) During ATP synthesis electrons pass through
b) Cytochromes

47) The net gain of ATP in glycolysis is
a) 6
b) 2
c) 4
d) 8

48) The net production of energy from one molecule of glucose during aerobic respiration is
a) 2 ATP
b) 4 ATP
c) 38 ATP
d) 40 ATP

49) The universal hydrogen acceptor is
a) NAD
b) ATP
c) CoA
d) FMN

50) Different steps in respiration are controlled by
a) Auxins
b) Sugar
c) Enzymes
d) Kinins

51) The alternate name of Krebs cycle is
a) Glyoxylate cycle
b) EMP pathway
c) Citric acid cycle
d) Glycolate cycle

52) Both respiration and photosynthesis require
a) Sunlight
b) Chlorophyll
c) Glucose
d) Cytochromes

53) Respiration in the absence of oxygen commonly occurs in
a) Solanum tuberosum
b) Spirogyra
c) Yeast
d) Homo sapiens

54) In plants energy is produced during the process of
a) Photosynthesis
b) Transpiration
c) Respiration
d) Water absorption

55) The complete oxidation of one molecule of glucose gives rise to
a) 6860,000 cal
b) 686,000 cal
c) 68,600 cal
d) 6,860 cal

56) Which among the following is the most appropriate reason for storing green (unripe) apples at a low temperature?
a) The rate of photosynthesis is reduced
b) Respiration and photosynthesis are completely inhibited
c) The rate of respiration is reduced
d) The rates of photosynthesis and respiration are reduced

57) The incomplete breakdown of sugars in anaerobic respiration forms
a) Fructose and water

58) Which of the following is the substrate for respiration?
a) RNA
b) DNA
c) ATP
d) Stored food

59) Carbon dioxide is liberated during
a) Photosynthesis
b) Respiration
c) Transpiration
d) Ascent of sap

60) In Krebs cycle
b) ADP is converted into ATP
d) Pyruvic acid is converted into ATP

61) The respiration of young maturing seeds is quite high but as water content decreases during maturation, the rate of respiration
a) Remains high
b) Stops completely
c) Increases steadily
d) Decreases steadily

62) Alcohol is a product of
a) Anaerobic respiration
b) Aerobic respiration
c) Photosynthesis
d) Glycolysis

63) Respiration is found in
a) In all living cells in light
b) All living cells in dark
c) In all living cells both in the light and in the dark
d) Only in non green cells both in light and dark

64) Fermentation is performed by
a) All microorganisms
b) All fungi
c) All bacteria
d) Some fungi and bacteria

65) Respiration differs from combustion in
a) Liberating more energy as compared to combustion
b) Liberation of all the energy at once in contrast to combustion
c) Liberation of energy gradually in steps in contrast to combustion
d) Carbohydrates take part as the combustion substance

66) In mitochondria, ATP synthesis occurs
a) At the outer membrane
b) At the cristae
c) In the matrix
d) In the intra-cristal space

67) The hexose monophosphate shunt is the
a) Transformation of glucose to pyruvic acid
b) Formation of new products
c) Sum total of metabolic reactions
d) Pentose phosphate pathway

68) Oxidative phosphorylation is found in the
a) Chloroplasts
b) Leucoplasts
c) Peroxisomes
d) Mitochondria

69) The cut surfaces of fruits often become dark due to
a) Dirty knife
b) Oxidation of iron-containing chemicals
c) Dissolution of iron of the knife
d) Oxidation of tannic acid assisted by traces of iron from knife

70) Citric acid cycle is the alternate name of the
a) HMP shunt
b) Glycolysis
c) TCA cycle
d) Calvin cycle

71) The R.Q. of protein-rich pulses is
a) Unity
b) Infinity
c) More than unity
d) Less than one

72) The number of ATP molecules which can be produced by the complete oxidation of pyruvic acid is
a) 6
b) 2
c) 15
d) 30

73) The oxidation of a molecule of acetyl CoA produces
a) 12 ATP
b) 15 ATP
c) 6 ATP
d) 19 ATP

74) The complete oxidation of a molecule of glucose yields
a) 15 ATP molecules
b) 36 ATP molecules
c) 2 ATP molecules
d) 8 ATP molecules

75) In germinating castor seeds, R.Q. is
a) Less than one
b) More than one
c) One
d) Zero

76) Fermentation is accompanied by the
a) Consumption of energy
b) Storage of energy
c) Liberation of energy
d) Neither consumption nor liberation of energy

77) More is evolved than the volume of oxygen consumed when the respiratory substrate

a) Sucrose
b) Fat
c) Glucose
d) Organic acid

78) In the presence of carbon monoxide, cyanide and azide, the rate of respiration
a) Decreases
b) Remains unchanged
c) Increases
d) Increases initially but declines afterwards

79) The R.Q. is the ratio of
c) Oxygen consumed to water produced

80) When one glucose molecule is completely oxidised, it changes
a) 36 ADP molecules into 36 ATP molecules
b) 38 ADP molecules into 38 ATP molecules
c) 30 ADP molecules into 30 ATP molecules
d) 32 ADP molecules into 32 ATP molecules

81) A device used to measure the rate of respiration of a living organism is the
a) Auxanometer
b) Potometer
c) Respirometer
d) Manometer

82) The enzyme helping in oxidative decarboxylation of pyruvic acid is
a) Pyruvate kinase
b) Pyruvate dehydrogenase
c) Malate dehydrogenase
d) Succinic dehydrogenase

83) The end product of the citric acid/Krebs cycle is
a) Citric acid
b) Lactic acid
c) Pyruvic acid

84) are end products of the
a) Anabolic process
b) Physical process
c) Catabolic process
d) Biophysical process

85) Out of 38 ATP molecules produced per glucose, 32 ATP molecules are formed
from in the

a) Respiratory chain
b) Krebs cycle
c) Oxidative decarboxylation
d) EMP

86) Which would be the last substrate to be used in respiration?
a) Carbohydrate
b) Protein
c) Fat
d) Organic acids

87) NAD of the Krebs cycle functions as an
a) Acceptor of hydrogen ions and electrons
b) Oxygen acceptor
c) Oxygen donor
d) Donor of phosphate ions

88) The fermentation products of Yeast are

89) Cytochromes are
a) Electron acceptors
b) Protein acceptors
c) Oxygen acceptors
d) Passage way for carbohydrates

90) The site of Krebs cycle in bacteria is the
a) Nucleoid
b) Cytoplasm
c) Plasma membrane
d) Ribosomes

91) In animal cells, the first stage of glucose breakdown is
a) Krebs cycle
b) Glycolysis
c) Oxidative phosphorylation
d) E.T.C.

92) Which one is a product of aerobic respiration?
a) Malic acid
b) Ethyl alcohol
c) Lactic acid
d) Pyruvic acid

93) Fructose 1,6 biphosphate splits into two triose phosphates by the action of the enzyme
a) Aldolase
b) Amylase
c) Zymase
d) Lipase

94) How much usable energy is available during oxidative combustion of 1 gm
mole of glucose in the body?

a) 686000 cal
b) 304000 cal
c) 262800 cal
d) 686 cal

95) The mitochondrial matrix has enzymes for the
a) Krebs cycle
b) TCA cycle and electron transport
c) Glycolysis and TCA cycle
d) Both B and C

96) What is produced when succinyl CoA is changed to succinate?
a) ATP
b) GTP
c) CTP
d) ATP in plants and GTP in animals

97) The number of ATP produced from one pyruvic acid molecule during conversion to acetyl
CoA is

a) 3
b) 5
c) 8
d) 15

98) The correct sequence of electron acceptors in ATP synthesis is

99) The anaerobic process after glycolysis is known as the
a) TCA cycle
b) Krebs cycle
c) Calvin cycle
d) None of the above

100) The electron transport system of mitochondria is located in the
a) Outer membrane
b) Inner membrane
c) Inter-cristal space
d) Outer chamber


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