Photosynthesis, Respiration and Nitrogen Metabolism - Plant Physiology and Biochemistry - Life Sciences Previous Year Questions

1

2007 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2007

The gas Q is

A

CO₂

B

O₂

C

N₂

D

NH₃

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2

2008 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2008

C₄ photosynthesis is a biochemical and structural syndrome that enhances

A

Concentration of CO₂ in the bundle sheath cells

B

Photorespiration

C

Requirement of water and nitrogen

D

Lower radiation use efficiency

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3

2009 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2009

Identify the CORRECT statements :
P. Vernalization is the process where flowering is promoted by heat shock.
Q. The four different types of floral organs are initiated as separate whorls.
R. The flowering stimulus is transported to the meristem via the xylem.
S. Abscisic acid synthesis occurs via the carotenoid biosynthetic pathway.

A

P, Q

B

Q, S

C

R, S

D

P, R

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4

2010 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2010

Identify the CORRECT statements from the following
P. Lenticels are the small pores present on the surface of the stem or branches of woody plants
Q. Glyoxysomes contain chlorophyll molecules in their thylakoid membranes
R. The enzyme ribulose 1, 5 bisphosphate carboxylase is otherwise known as carboxydohydratase
S. 18 ATP and 12 NADPH molecules are utilized for fixing 6 molecules of CO₂ in the dark reaction of photosynthesis

A

P, Q

B

P, R

C

Q, R

D

P, S

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5

2010 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2010

Which of the following statements in plant respiration are CORRECT?
P. The oxidative Pentose Phosphate Pathway can accomplish the oxidation of glucose in the stroma of mitochondria
Q. ATP is produced in the reaction step of TCA cycle catalyzed by succinyl CoA synthetase
R. In addition to Cytochrome c oxidase, an alternative oxidase enzyme resistant to cyanide reduces oxygen molecule in the electron transport system
S. In Glyoxylate cycle acetyl CoA reacts with citrate to form α-keto glutarate

A

P, R

B

P, Q

C

Q, R

D

Q, S

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6

2011 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2011

Which one of the following enzymes fixes CO₂ into organic form?

A

Ribulose 5-phosphate kinase

B

Ribulose 1,5-bisphosphate carboxylase

C

Pyruvate dehydrogenase

D

Carbonic anhydrase

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7

2011 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2011

During photorespiration the reactive oxygen species, H₂O₂ is produced in

A

Glyoxysome

B

Lysosome

C

Peroxisome

D

Dictyosome

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8

2011 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2011

Which of the following statements in photosynthesis are CORRECT? P. The absorption maxima for photosystem I (PS I) and PS II are 680 nm and 700 nm, respectively Q. Photosynthetic reaction centre contains 300 chlorophyll molecules and the release of one molecule of oxygen requires a minimum of 8 photons R. The non-photochemical quenching of excitation energy is enhanced by the presence of zeaxanthin S. The photochemical splitting of water occurs in PS I

A

P, Q

B

R, S

C

P, S

D

Q, R

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9

2012 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2012

Leguminous plants maintain a very low concentration of free oxygen in their root nodules because

A

the nitrogen fixing bacteria living in the root nodules are anaerobic

B

of binding of oxygen to leghemoglobin

C

reductase enzyme of the nitrogenase complex helps in removal of O₂

D

nitrogenase enzyme of the nitrogenase complex helps in removal of O₂

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10

2012 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2012

Which one of the following performs normal C₃ photosynthesis when water is available, but switches to crassulacean acid metabolism (CAM) during salt or drought stress?

A

Mesembryanthemum crystallinum

B

Cynodon dactylon

C

Eleucine coracana

D

Hordeum vulgare

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11

2013 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2013

In the symbiotic nitrogen fixation process, Leghemoglobin present in the nodule helps in fixing nitrogen in presence of the enzyme

A

Nitrate synthetase

B

Nitrate synthase

C

Glutathione synthetase

D

Nitrogenase

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12

2013 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2013

Which two of the following are the INCORRECT statements?
P. All plants fix CO2 by the action of ribulose bisphosphate carboxylase. The reaction occurs in the bundle sheath of C4 plants
Q. All plants fix CO2 by the action of ribulose bisphosphate carboxylase. The reaction occurs in the mesophyll cells of C4 plants
R. Phosphoenol pyruvate + CO2 → Oxaloacetate + Pi, catalyzed by the enzyme phosphoenol pyruvate carboxylase occurs in the mesophyll cells of C4 plants
S. Phosphoenol pyruvate + CO2 → Oxaloacetate + Pi, catalyzed by the enzyme phosphoenol pyruvate dehydrogenase occurs in the mesophyll cells of C4 plants

A

P, Q

B

Q, R

C

Q, S

D

P, R

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13

2014 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2014

Find the CORRECT statements in the context of Global warming effect on plant photosynthesis.
P. Decreasing aqueous solubility of dissolved CO₂ compared to dissolved O₂
Q. Decreasing oxygenase activity of Rubisco relative to carboxylation
R. Enhancing the ratio of CO₂ to O₂ in air equilibrated solution
S. Increasing photorespiration relative to photosynthesis

A

P & Q

B

R & S

C

P & R

D

P & S

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14

2015 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2015

Which of the following statements are TRUE with regard to the similarities between Crassulacean Acid Metabolism (CAM) and C₄ cycle?
P. Stomata open during night and remain closed during the day
Q. PEPcase is the carboxylating enzyme to form C₄ acid
R. C₄ acid is decarboxylated to provide CO₂ for C₃ cycle
S. Kranz anatomy is predominant in both CAM and C₄ plants

A

P, S

B

Q, R

C

P, Q

D

R, S

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15

2015 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2015

With respect to germination of seeds, the CORRECT sequence of events is
P. Seed imbibes water
Q. Mobilization of starch reserve to embryo
R. Diffusion of gibberellin from embryo to aleurone layer
S. Synthesis of α-amylase in the aleurone layer

A

P, Q, S, R

B

P, R, S, Q

C

R, P, Q, S

D

R, Q, P, S

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16

2017 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2017

Which one is TRUE for Calvin cycle?

A

Glycerol 3-phosphate is generated in this cycle

B

CO2 is not consumed in this cycle

C

This is a reductive pentose phosphate cycle

D

Ribose 5-phosphate is a carboxylation substrate in this cycle

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17

2017 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2017

Choose the CORRECT set of matches between group I and group II in relation to nitrogen fixation and assimilation

A

P-4, Q-3, R-2, S-1

B

P-4, Q-3, R-1, S-2

C

P-1, Q-2, R-4, S-3

D

P-3, Q-4, R-2, S-1

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18

2017 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2017

Which TWO of the following reactions are INCORRECT in relation to C₂ oxidative photosynthetic carbon cycle in land plants?
P. 2 (Ribulose-1,5-bisphosphate) + 2(CO₂) → 2 (phosphoglycolate) + 2 (3-phosphoglycerate) + 4H⁺
Q. Serine + α-ketoglutarate → hydroxypyruvate + glutamine
R. 2 (Phosphoglycolate) + 2(H₂O) → 2 (glycolate) + 2Pi
S. Hydroxypyruvate + NADH + H⁺ → glycerate + NAD⁺

A

P and Q

B

Q and R

C

R and S

D

S and P

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19

2018 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2018

Select the CORRECT combination of the following statements.
P. The cyclic electron transport chain involving PSI results in net production of both ATP and NADPH
Q. The cyclic electron transport chain involving PSI results in net production of ATP
R. Rubisco enzyme usually converts RuBP and CO₂ into 2-phosphoglycolate and 3-phosphoglycerate
S. Rubisco enzyme usually converts RuBP and O₂ into 2-phosphoglycolate and 3-phosphoglycerate

A

P, Q

B

R, S

C

Q, S

D

P, R

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20

2019 · Life Sciences · Plant Physiology and Biochemistry · Photosynthesis, Respiration and Nitrogen Metabolism

Life Sciences (XL) 2019

The light-harvesting pigment NOT used by Cyanobacteria for photosynthesis is

A

Rhodopsin

B

Phycobilin

C

Phycoerythrobilin

D

Phycocyanobilin

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