Explore topic-wise MCQs in Biology.

This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.

1.

Why is the productivity of C4 plants better than that of C3 plants?

A. C<sub>4</sub> plants show Kranz anatomy
B. C<sub>4</sub> plants lack photorespiration
C. C<sub>4</sub> plants show high phosphoglycerate formation
D. C<sub>4</sub> plants show high phosphoglycolate formation
Answer» C. C<sub>4</sub> plants show high phosphoglycerate formation
2.

Which of these is a 2-carbon molecule?

A. Phosphoglycolate
B. OAA
C. PGA
D. Malic acid
Answer» B. OAA
3.

Which of these are synthesized during photorespiration?

A. NADPH
B. ATP
C. CO<sub>2</sub>
D. Sugars
Answer» D. Sugars
4.

Which of these is not true regarding photorespiration?

A. ATP is not synthesized
B. 1 molecule of phosphoglycerate is formed
C. 1 molecule of PGA is formed
D. The active site of RuBisCO binds to oxygen
Answer» D. The active site of RuBisCO binds to oxygen
5.

What is formed when the active site of RuBisCO binds to oxygen?

A. ATP
B. OAA
C. PGA
D. Phosphoglycolate
Answer» E.
6.

When CO2: O2 is approximately 1, RuBisCO has a lower affinity for CO2. True or false?

A. True
B. False
Answer» C.
7.

Why is carbon dioxide fixation decreased in some C3 plants?

A. Phosphoglycerate formation
B. Unavailability of RuBP
C. Oxygen binds to RuBisCO
D. Oxygen binds to RuBP
Answer» D. Oxygen binds to RuBP
8.

What factor determines the binding of carbon dioxide to the active site of RuBisCO?

A. Intensity of sunlight
B. Number of chloroplasts
C. Opening and closing of stomata
D. Relative O<sub>2</sub> and CO<sub>2</sub> concentration
Answer» E.
9.

What does the name RuBisCO imply?

A. Its active site can bind to oxygen and carbon dioxide
B. It leads to the combination of oxygen and carbon dioxide
C. It uses carbon and oxygen to breakdown sugar
D. It uses carbon and oxygen to breakdown RuBP
Answer» B. It leads to the combination of oxygen and carbon dioxide
10.

What is the most abundant enzyme in the world?

A. Papain
B. Alpha amylase
C. RuBisCO
D. Horse radish peroxidase
Answer» D. Horse radish peroxidase
11.

Complete the reaction.
RuBP + CO2

A. 3 3PGA
B. 2 3PGA
C. 2 3PGA + RuBisCO
D. 3 3PGA + RuBisCO
Answer» C. 2 3PGA + RuBisCO
12.

Which of these is true regarding carbon dioxide fixation?

A. RuBP and CO<sub>2</sub> give PGA
B. RuBisCO combines with CO<sub>2</sub>
C. 3 molecules of 2PGA are formed
D. RuBP acts as a catalyst
Answer» B. RuBisCO combines with CO<sub>2</sub>
13.

Which of these take place in the first step of the Calvin pathway?

A. 3 molecules of 2PGA are formed
B. RuBisCO combines with CO<sub>2</sub>
C. RuBP and CO<sub>2</sub> give PGA
D. RuBP acts as a catalyst
Answer» D. RuBP acts as a catalyst
14.

What is the first step of the Calvin pathway?

A. Regeneration
B. Reduction
C. CO<sub>2</sub> fixation
D. Synthesis of sugar
Answer» D. Synthesis of sugar
15.

Which of these cannot help us differentiate between C3 and C4 plants?

A. Carbon dioxide acceptor molecule
B. Presence of Kranz anatomy
C. Photorespiration
D. Number of chloroplasts
Answer» E.