MCQ on Photosynthesis in Higher Plants

Mcqs on Photosynthesis in Higher Plants

1. In sugarcane plant, ¹⁴ CO₂ is fixed in a malic acid, in which the enzyme that fixes carbon dioxide is

a) Ribulose phosphate kinase    
b) Fructose phosphatase
c) Ribulose bisophosphate carboxylase 
d) Phosphoenol Pyruvic acid carboxylase

2. For yielding one molecule of glucose, the Calvin cycle turn
a) Two times     
b) Four times    
c) Six times        
d) Eight times

3. The light reaction of photosynthesis end up in the formation of
a) NaDH₂  
b) ATP  
c) Sugar
d) NADPH₂

4. In leaves of C₄-plants, malic acid synthesis during carbon dioxide fixation occurs in

a) Epidermal cells            
b) Mesophyll cells           
c) Bundle sheath cells    
d) Guard cells

5. Biosynthetic phase of photosynthesis is the formation of

a) Lipid
b) Fat   
c) Protein           
d) Sugars

6. What happen to the chloroplast pigment when they absorb light?

a) They become reduced             
b) They become excited
c) They lose potential energy     
d) Calvin cycle is triggered

7. In C₄-pathway, the first product identified was

a) 3-PGA             
b) OAA
c) 2-PGA             
d) 1-3DPGA

8. Law of limiting factors was given by

a) Leibig              
b) Blackman      
c) Calvin              
d) Arnon

9. PS-I in cyclic photophosphorylation is involved in the formation of …A… by …B… movement of electrons

What does A and B refer here?

a) A-ATP; B-down hill redox potential     
b) A-ADP; B-up hill redox potential
c) A-NADH + H^+; B-down hill energy     
d) A-NADPH + H^+; B-down hill energy

10. The green-coloured pigment present in all autotrophs was named chlorophyll by

a) Pelletier Caventou     
b) Julius Robert Mayer  
c) Jean Senebier              
d) Melvin Calvin

11. Within the chloroplast, there is the membranous system consisting of

I. grana

II. stroma lamellae

III. fluid stroma

Choose the correct option
a) I and II            
b) II and III          
c) I and III           
d) I, II and III

12. Joseph Priestley observed that when mouse alone was placed in a closed bell jar with burning candle, it was suffocated and candle burning extinguished but when mouse was placed with a mint plant in the same bell jar, that mouse stayed alive and candle continued to burn. What he concluded from this experiment?

a) Burning candle remove the air              
b) Mint plant restore the air
c) Both (a) and (b)           
d) CO₂ is required for burning of candle

13. Organelles involved in photorespiration is/are

I. chloroplast

II. peroxisomes

III. mitochondria

Choose the correct option

a) I and II            
b) II and III          
c) III and I            
d) I, II and III

14. The first step in dark reaction of photosynthesis is

a) Formation of ATP

b) Ionization of water

c) Attachment of carbon dioxide to a pentose sugar

d) Excitement of electron of chlorophyll by a photon of light

15. Calvin cycle is also called

a) Calvin-Benson cycle  
b) C₃-cycle
c) Reductive pentose pathway  
d) All of the above

16. Plants in which the first product of CO_2 fixation is C_3 acid, i.e., the …A… pathway, and those in which the first product was C_4 acid (OAA), i.e., the …B… pathway

Complete the given statement by filling appropriate options in the given blanks

a) A-C₂; B-C₃      
b) A-C₃; B-C₄      
c) A-C₄; B-C₂       
d) A-C₂; B-C₃0

17. Photosynthesis is an important process for life on earth because

a) It is the primary source of all food on earth

b) It is responsible for the release the of oxygen

c) It is the only natural process responsible for the utilisation of sunlight
d) All of the above

18. The mineral involved in the photolysis of water are

I Manganese                 
II Calcium
III magnesium             
IV Chloride

a) I and II only   
b) I, II and IV only            
c) I, II and II only              
d) I and IV only

19. Calvin cycle represents

a) Reductive carboxylation          
b) Substrate level phosphorylation
c) Dark respiration          
d) Oxidative carboxylation

20. Identify the correct sequence of enzymes given below which participate in the regeneration phase of Calvin cycle.

I. Ribulose-5-phosphate isomerase

II. Ribulose-5-phosphate epimerase

III. Transketolase

IV. Triose phosphate isomerase

a) VI, I, III, II        
b) III, IV, II, I       
c) IV, III, I, II        
d) II, I, IV, III

1.    (d)

In C_4-plants, carbon dioxide is picked up by phospho-enol pyruvate (PEP) and the reaction being catalysed by PEP carboxylase.

2 (c)

Conversion of carbon dioxide to simple (reduced) organic compounds is called carbon dioxide assimilation or carbon dioxide fixation or carbon fixation. This fixation pathway was elucidated in the early 1950s by Melvin Calvin and co-workers and is often called as Calvin cycle.

Since, one molecule of carbon is fixed in one turn of the Calvin cycle. So, six turns of the cycle are required to fix the glucose molecule containing six carbon atmos.

3 (d)

The light reaction of photosynthesis ends up in the formation of NADPH₂ from NADP⁺

4 (b)

In C₄-plants, the Hatch and Slack pathway involves two carboxylation reaction, one taking place in chloroplast of mesophyll cells and other in chloroplast of bundle sheath cells.

5 (d)

Synthesis of sugars or carbohydrates is called the biosynthetic phase of photosynthesis. This process does not directly depends on the presence of light but is dependent on the products of the light reaction, i.e., ATP and NADPH, besides CO₂ and H₂O. This could be verified immediately after light becomes unavailable. The biosynthetic process continues for sometime and then stops. If then, light is made available, the synthesis starts again

6 (b)

Light reaction begins with the PS-II. In photosystem-II the reaction centre chlorophyll-a absorb 680 nm. wavelength of red light causing electrons to become excited and jump into orbit further from the nucleus. These electrons are picked up by an electron acceptor, which passes them to an electron system consisting of cytochromes

7 (b)

CO₂ assimilation during photosynthesis generally takes place in two ways in plants

(i) C₃ pathway Those plants in which the first product of CO₂ fixation is a C₃ acid (PGA), i.e., the C₃ pathway

(ii) C₄ pathway Those plants in which the first product C₄ acid (OAA), i.e., the C₄ pathway

8 (b)

Blackman (1905) extended the law of minimum to formulate the law of limiting factors, which in his own words is ‘when a process is conditioned as to its rapidity by a number of separate factors, the rate of the process is limited by the pace of slowest factor.’

9 (d)

Only PS-I is involved in cyclic photophosphorylation the formation of ATP when the electrons move down hill in term of redox potential

10 (b)

Julius Robert Mayer gave name chlorophyll to green pigment present in autotrophs.

11 (a)

Within the chloroplast, there is the membranous system (grana, stroma lamellae) and fluid it is called stroma

12 (c)

Joseph Priestley observed that a candle burning in a closed, a bell jar, soon gets extinguished. Similarly, a mouse would soon suffocate in a closed space. He concludes that a burning candle or an animal that breathe the air, both somehow, damage the air.

But when he placed a mint plant in the same bell jar, he found that the mouse stayed alive and the candle continued to burn. Priestly hypothesised that plants restore to the air whatever breathing animals and burning candles remove

13 (d)

In photorespiration, the three subcellular compartments namely, the chloroplast, peroxisomes and mitochondria are involved

14 (c)

The first step in dark reaction of photosynthesis is Carboxylation, in which six molecules of carbon dioxide Carboxylation, in which six molecules of carbon dioxide combine with six molecules of ribulose 1, 5-biphosphate (RuBP) to form six molecules of unstable six carbon compound. Carboxylation of RuBP is catalysed by the enzyme RuBP carboxylase or RUBISCO.

15 (d)

The other names for Calvin cycle are Calvin Benson Cycle, C₃-cycle, and reductive pentose phosphate pathway

16 (b)

CO₂ assimilation during photosynthesis generally takes place in two ways in plants

(i) C₃ pathway Those plants in which the first product of CO₂ fixation is a C₃ acid (PGA), i.e., the C₃ pathway

(ii) C₄ pathway Those plants in which the first product C₄ acid (OAA), i.e., the C₄ pathway

17 (c)

Ultimately, all living forms on the earth depends on sunlight for energy. The use of energy from sunlight by the plants for doing photosynthesis is the basis of life on earth. Photosynthesis is important due to two reasons. It is the primary source of food on earth and it is responsible for the release of oxygen into the atmosphere by green plants

18 (d)

Photolysis of water involves the splitting of water molecules into OH^- and H⁺ ions in the presence of light. This phenomenon is associated with pigment system-II and is catalysed by the presence of Mn⁽²⁺⁾ and CI^- ions.

20 (c)

Triose phosphate isomerase enzyme converts glyceraldehydes-3 phase molecule into dihydroxy acetone phosphate. Then an enzyme transketolase comes, which acts on sedoheptulose-7-phosphate molecule and changes it into ribulose-5-phosphate and xylulose-5-phosphate. Then ribulose-5-phosphate isomerase enzyme comes and acts on ribulose-5-phosphate. This reactionhas a molecule of ribulose-5-phosphate, while xylulose-5-phosphate molecule is also converted into ribulose-5-phosphate by ab other enzyme, ribulose-5-phosphate epimerase.