Respiration in Plants — Page 2 | NEET Biology

Q11

Krebs cycle occurs in

A mitochondria

B cytoplasm

C chloroplasts

D ribosomes

Correct Answer

Option A

Solution

(a) Krebs cycle (TCA cycle) occurs in the mitochondrial matrix.

Q12

Connecting link between glycolysis and Krebs cycle is

A oxaloacetate

B PEP

C pyruvate

D acetyl CoA

Correct Answer

Option D

Solution

(d) Pyruvate is oxidatively decarboxylated to acetyl CoA (link reaction) before entering Krebs cycle.

Q13

In Krebs cycle FAD participates as electron acceptor during conversion of

A succinyl CoA to succinic acid

B alpha-ketoglutarate to succinyl CoA

C succinic acid to fumaric acid

D fumaric acid to malic acid

Correct Answer

Option C

Solution

(c) FAD is reduced to FADH2 during the conversion of succinate to fumarate by succinate dehydrogenase.

Q14

The mechanism of ATP formation in both chloroplast and mitochondria is explained by

A relay pump theory of Godlewski

B Munch pressure/mass flow model

C chemiosmotic theory of Mitchell

D Cholodny-Went model

Correct Answer

Option C

Solution

(c) Mitchell's chemiosmotic theory explains ATP synthesis via proton gradient in both organelles.

Q15

In which one of the following do the two names refer to one and the same thing?

A Tricarboxylic acid cycle and urea cycle

B Krebs cycle and Calvin cycle

C Tricarboxylic acid cycle and citric acid cycle

D Citric acid cycle and Calvin cycle

Correct Answer

Option C

Solution

(c) TCA cycle = citric acid cycle = Krebs cycle — all names for the same pathway.

Q16

During anaerobic digestion of organic waste, which one is left undegraded?

A Cellulose

B Lipids

C Lignin

D Hemi-cellulose

Correct Answer

Option C

Solution

(c) Lignin is a complex aromatic polymer highly resistant to anaerobic degradation.

Q17

Aerobic respiratory pathway is appropriately termed

A parabolic

B amphibolic

C anabolic

D catabolic

Correct Answer

Option B

Solution

(b) Amphibolic: aerobic respiration is both catabolic (breaks down molecules) and anabolic (provides biosynthetic intermediates).

Q18

The energy-releasing metabolic process in which substrate is oxidised without an external electron acceptor is called

A glycolysis

B fermentation

C aerobic respiration

D photorespiration

Correct Answer

Option B

Solution

(b) Fermentation is anaerobic — no external electron acceptor; substrate is oxidised internally.

Q19

In which one of the following processes is CO2 not released?

A Aerobic respiration in plants

B Aerobic respiration in animals

C Alcoholic fermentation

D Lactate fermentation

Correct Answer

Option D

Solution

(d) Lactic acid fermentation: pyruvate → lactate; no CO2 is released.

Q20

Phosphoenol Pyruvate (PEP) is the primary CO2 acceptor in

A C4 plants

B C2 plants

C C3 and C4 plants

D C3 plants

Correct Answer

Option A

Solution

(a) PEP is the primary CO2 acceptor in C4 plants (mesophyll cells).