Biology · chapter PYQs

Respiration in Plants, on the exam screen.

4 questions from NEET 2026, Re-NEET 2026, NEET 2020, 4 minutes, marked +4 / −1. See them with solutions.

Respiration in Plants · PYQs

Candidate: You

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Q1/4

Question 1 · NEET 2026 · Q107 · +4 / −1
$2(\,\mathrm{C}_{51}\mathrm{H}_{98}\mathrm{C}_{6}) + 145\,\mathrm{O}_{2} \rightarrow 102\,\mathrm{CO}_{2} + 98\,\mathrm{H}_{2}\mathrm{O} + \text{energy}$

The Respiratory Quotient (RQ) of a biomolecule used for respiration, as per the above equation would be :
Answer and explanation
Answer: (1)
The respiratory quotient is the ratio of the volume of $\mathrm{CO}_{2}$ evolved to the volume of $\mathrm{O}_{2}$ consumed. From the equation, $RQ = \frac{102}{145} \approx 0.7$ , which lies between 0.5 and 0.95, the range typical when fats are respired. It is not 1.0 (which is for carbohydrates) nor greater than 1.
Question 2 · NEET 2026 · Q128 · +4 / −1
Match List-I with List-II
List I (Process)
List II (Location)
P) Glycolysis
I) Inner mitochondrial membrane
Q) ETS
II) Mitochondrial matrix
R) Accumulation of protons
III) Cytoplasm
S) Krebs' cycle
IV) Intermembrane space
choose the correct answer from the options given below:
Answer and explanation
Answer: (3)
Glycolysis takes place in the cytoplasm (P-III), the electron transport system operates on the inner mitochondrial membrane (Q-I), protons accumulate in the intermembrane space during chemiosmosis (R-IV), and the Krebs' cycle runs in the mitochondrial matrix (S-II). This gives P-III, Q-I, R-IV, S-II.
Question 3 · Re-NEET 2026 · Q109 · +4 / −1
How many molecules of pyruvic acid are produced at the end of glycolysis from 206 molecules of glucose?
Answer and explanation
Answer: (4)
Glycolysis splits each six-carbon glucose into TWO three-carbon pyruvate molecules, so the yield is simply doubled: $206 \times 2 = 412$ . The carbon count checks out, since $6 = 3 + 3$ . NCERT Class 11, Respiration in Plants.
Question 4 · NEET 2020 · Q20 · +4 / −1
The number of substrate level phosphorylations in one turn of citric acid cycle is
Answer and explanation
Answer: (1)
In one turn of the citric acid cycle, there is one substrate-level phosphorylation event, which occurs during the conversion of succinyl-CoA to succinate. Chapter: Respiration in Plants.

List I (Process)	List II (Location)
P) Glycolysis	I) Inner mitochondrial membrane
Q) ETS	II) Mitochondrial matrix
R) Accumulation of protons	III) Cytoplasm
S) Krebs' cycle	IV) Intermembrane space