Biology Multiple Choice Questions on “Higher Plants Photosynthesis – ATP and NADPH-1”.
1. Which of these is not a product of light reaction?
a) Oxygen
b) NADPH
c) ATP
d) NADP
Answer: d
Clarification: The process of photosynthesis has two stages-the light reaction and the dark reaction. The products of the light reaction are oxygen, ATP and NADPH. The light reaction requires light to carry out its reactions.
2. Which of these diffuse out of the chloroplast after the light reaction?
a) ATP
b) Carbon dioxide
c) Oxygen
d) NADPH
Answer: c
Clarification: The process of photosynthesis has two stages-the light reaction and the dark reaction. The products of the light reaction are oxygen, ATP and NADPH. Oxygen diffuses out of the chloroplast.
3. Which of these statements is incorrect regarding the biosynthetic phase of photosynthesis?
a) It depends on carbon dioxide and water
b) It depends on the products of light reaction
c) ATP and NADH are used
d) Sugars are synthesized
Answer: c
Clarification: The biosynthetic phase of photosynthesis depends upon the products of the light reaction, which are namely oxygen, ATP and NADPH. It leads to the synthesis of food, which are sugars.
4. Which of these scientists have contributed to photosynthesis studies?
a) Melvin Calvin
b) Hargovind Khorana
c) Gregor Mendel
d) Anthony Van Leeuwenhoek
Answer: a
Clarification: Melvin Calvin has contributed greatly to photosynthesis studies. The Calvin cycle was named after him. He first identified the compound PGA or 3-phosphoglyceric acid as a product of photosynthesis.
5. Which of these was used by Melvin Calvin for photosynthesis studies?
a) P-35
b) Radioactive C-14
c) C-13
d) Radioactive S-32
Answer: b
Clarification: Melvin Calvin used the radioactive isotope of carbon-12 or C-12, carbon-14 or C-14 in algal photosynthesis studies. This helped in determining the various steps of the Calvin cycle or pathway.
6. Who discovered the first CO2 fixation product?
a) Anthony Van Leeuwenhoek
b) Robert Hooke
c) Melvin Calvin
d) Gregor Mendel
Answer: c
Clarification: Melvin Calvin has contributed greatly to photosynthesis studies. The Calvin cycle was named after him. He used radioactive C-14 to discover the first CO2 fixation product of photosynthesis, PGA.
7. Which of these is a 3-carbon organic acid?
a) PGA
b) BTCA
c) Citric acid
d) Acetic acid
Answer: a
Clarification: PGA or 3-phosphoglyceric acid is a 3-carbon organic acid. Citric acid has 6 carbon atoms while acetic acid has 2 carbon atoms. PGA is a product of the carbon dioxide fixation stage of photosynthesis.
8. What is the full form of PGA?
a) 2-phosphoglyceric acid
b) 2-phosphoglutamic acid
c) 3-phosphoglutamic acid
d) 3-phosphoglyceric acid
Answer: d
Clarification: The full form of PGA is 3-phosphoglyceric acid. 3-phosphoglyceric acid is a product of the carbon dioxide fixation stage of photosynthesis. 3-phosphoglyceric acid is a 3-carbon organic acid.
9. How many carbon atoms does OAA contain?
a) 3
b) 2
c) 4
d) 1
Answer: c
Clarification: OAA or oxaloacetic acid is a 4-carbon compound. It is an organic acid. OAA or oxaloacetic acid is the first stable product of carbon dioxide fixation during photosynthesis, in some plants.
10. CO2 assimilation during photosynthesis is of 3 types. True or false?
a) True
b) False
Answer: b
Clarification: Carbon dioxide assimilation during photosynthesis is of two types depending upon the first stable product of carbon dioxide fixation. The two types are the C3 pathway and the C4 pathway.
11. Which is the first product of CO2 fixation in the C3 pathway?
a) NADPH
b) OAA
c) ATP
d) PGA
Answer: d
Clarification: Carbon dioxide assimilation during photosynthesis is of two types depending upon the first stable product of carbon dioxide fixation. the first product of CO2 fixation in the C3 pathway is PGA.
12. Which is the first product of CO2 fixation in the C4 pathway?
a) NADPH
b) PGA
c) OAA
d) ATP
Answer: c
Clarification: Carbon dioxide assimilation during photosynthesis is of two types depending upon the first stable product of carbon dioxide fixation. the first product of CO2 fixation in the C4 pathway is OAA.
13. What is the primary acceptor of CO2 in photosynthesis?
a) ATP
b) PGA
c) RuBP
d) OAA
Answer: c
Clarification: The primary acceptor of carbon dioxide in photosynthesis is RuBP or ribulose bisphosphate. Ribulose bisphosphate is a 5-carbon ketose sugar. It accepts carbon dioxide from the atmosphere.
14. Which of these compounds have 5 carbon atoms?
a) RuBP
b) OAA
c) PGA
d) ATP
Answer: a
Clarification: RuBP or Ribulose bisphosphate is a 5-carbon ketose sugar. It is the primary acceptor of carbon dioxide in photosynthesis. OAA is a 4-carbon organic acid while PGA is a 3-carbon organic acid.
15. How many carbon atoms does the primary acceptor of CO2 in photosynthesis have?
a) 4
b) 5
c) 3
d) 2
Answer: b
Clarification: RuBP or Ribulose bisphosphate is a 5-carbon ketose sugar. It is the primary acceptor of carbon dioxide in photosynthesis. It accepts carbon dioxide from the atmosphere for the process of photosynthesis.