Q.109 Botany ⭐ 360° Option Elimination Active

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NEET 2026 Botany Question 109 Solution

Topic: Respiration in Plants · Official NTA Booklet Code 50

Question

How many molecules of pyruvic acid are produced at the end of glycolysis from 206 molecules of glucose?

(1)206
(2)309
(3)103
(4)412

✓

Verified Against NTA Final Answer Key

Option (4) : 412

📚 Respiration in Plants Easy

📋 Given Parameters & Problem Setup

Starting Substrate 206 molecules of glucose (C₆H₁₂O₆)

Metabolic Pathway Glycolysis (EMP pathway in cytoplasm)

⚡

The 30-Second Exam Hall Shortcut: ⚡ 1 Glucose = 2 Pyruvate Rule

⏱️ Save ~40 seconds

Simply multiply the number of glucose molecules by 2!

1 Recall fundamental glycolysis cleavage stoichiometry:

2 1 molecule of 6-carbon glucose yields 2 molecules of 3-carbon pyruvic acid.

3 Calculate: 206 × 2 = 412.

4 Option (4) is 412. Done in 3 seconds!

🛡️

Why You Can 100% Trust This Shortcut: Universal biochemical law: C₆H₁₂O₆ -> 2 CH₃COCOOH.

📐

Step-by-Step Rigorous Workflow & Mathematical Proof

Step 1

Biochemical Equation of Glycolysis

Glycolysis occurs in the cytoplasm of all living cells. A single molecule of hexose sugar (glucose, 6 carbons) undergoes a 10-step enzymatic sequence ending with cleavage into two molecules of triose keto-acid (pyruvic acid, 3 carbons).

1\text{ Glucose (6C)} + 2\text{NAD}^+ + 2\text{ADP} + 2\text{P}_i \xrightarrow{\text{EMP}} 2\text{ Pyruvic acid (3C)} + 2\text{NADH} + 2\text{H}^+ + 2\text{ATP}

• Stoichiometric yield: 2 pyruvic acid molecules per 1 glucose molecule consumed.

Step 2

Calculate for 206 Molecules of Glucose

Multiply the input glucose quantity by the stoichiometric conversion factor of 2.

\text{Molecules of Pyruvic Acid} = 206 \times 2 = 412

• 206 × 2 = 412 molecules of pyruvic acid.

Step 3

Evaluate Against Options

Looking at the available options: (1) 206, (2) 309, (3) 103, (4) 412. Option (4) is the exact calculated value.

\text{Correct Option} = \mathbf{412} \; [\text{Option (4)}]

• Matches official NTA final answer key Option D / (4).

⭐

360° Option Elimination Engine Key Feature

Diagnose every choice: Know exactly why the right option works and why distractors fail.

4-Option Deep Scan

1 A

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Assumes a 1:1 stoichiometric ratio between glucose and pyruvic acid.

⚠️

Student Fallacy (Why candidates pick this trap): Ignoring the enzymatic splitting of fructose-1,6-bisphosphate into two triose molecules.

2 B

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Represents a 1.5 ratio, which is chemically impossible.

⚠️

Student Fallacy (Why candidates pick this trap): Arithmetic miscalculation.

3 C

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Divides 206 by 2 instead of multiplying.

⚠️

Student Fallacy (Why candidates pick this trap): Confusing substrate-to-product stoichiometry by dividing instead of multiplying.

4 D

✓ 100% Correct

Verdict & Scientific Reason:

100% mathematically and biochemically exact: 206 × 2 = 412.

💡

Why this is airtight: None; precise stoichiometry.

⚠️

NTA Trap Alert: Inverting the Multiplication Factor

Some hurried students see "2 pyruvic acid per glucose" and divide the number of glucose molecules by 2, yielding 103 (Option 3).

🛡️ How to avoid the -1 mark: Always remember: 1 6-carbon molecule breaks into TWO 3-carbon molecules. The number of molecules must DOUBLE!

📖

Core NEET Syllabus Standard

NEET Biology Core Syllabus · Respiration in Plants Standard Benchmark

Core Scientific Principle Tested:

"In glycolysis, partial oxidation of one molecule of glucose gives rise to two molecules of pyruvic acid."

Syllabus Focus: Glycolysis

✓ Core NEET UG Syllabus Anchor Syllabus & Academic Standards ↗

One glucose splits in two, so two hundred and six gives four hundred and twelve for you!

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NEET 2026 Botany Question 109 Solution

Question

The 30-Second Exam Hall Shortcut: ⚡ 1 Glucose = 2 Pyruvate Rule

Step-by-Step Rigorous Workflow & Mathematical Proof

Biochemical Equation of Glycolysis

Calculate for 206 Molecules of Glucose

Evaluate Against Options

360° Option Elimination Engine Key Feature

NTA Trap Alert: Inverting the Multiplication Factor

Core NEET Syllabus Standard

Ready to attempt under real exam pressure?

🔗 Related Questions — Respiration in Plants

Enzyme Complexes of the Mitochondrial Electron Transport Chain

Tricarboxylic Acid (TCA) Cycle: Substrate-Level Phosphorylation vs Oxidation

Cellular Compartments for Respiratory Processes

Glycolysis: ATP-Consuming Phosphorylation Steps

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