Q.76 Chemistry ⭐ 360° Option Elimination Active

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NEET 2021 Chemistry Question 76 Solution

Topic: Biomolecules · Official NTA Booklet Code M1

Question

The RBC deficiency is deficiency disease of:

(1)Vitamin B12
(2)Vitamin B6
(3)Vitamin B1
(4)Vitamin B2

✓

Verified Against NTA Final Answer Key

Option (1) : Vitamin B12

📚 Biomolecules Easy

📋 Given Parameters & Problem Setup

Deficiency Condition RBC deficiency (Pernicious anaemia)

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The 30-Second Exam Hall Shortcut: ⚡ B12 Deficiency = Pernicious Anaemia (RBC Deficiency)

⏱️ Save ~15 seconds

Verbatim NCERT Biomolecules Vitamins Table: Vitamin $B_{12}$ (Cyanocobalamin) deficiency causes Pernicious anaemia (RBC deficiency in haemoglobin). Vitamin $B_1$ causes Beri-beri, Vitamin $B_2$ causes Cheilosis, and Vitamin $B_6$ causes Convulsions. Match Option (1)!

1 Recall NCERT Biomolecules Table 14.3: Vitamins, Sources and Deficiency Diseases.

2 Vitamin B12: Pernicious anaemia (RBC deficiency in haemoglobin).

3 Vitamin B1 (Thiamine): Beri-beri (loss of appetite, retarded growth).

4 Vitamin B2 (Riboflavin): Cheilosis (fissuring at corners of mouth and lips).

5 Vitamin B6 (Pyridoxine): Convulsions.

6 Match Option (1) Vitamin B12.

🛡️

Why You Can 100% Trust This Shortcut: Canonical NCERT Biomolecules classification of vitamins and deficiency diseases.

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Step-by-Step Rigorous Workflow & Mathematical Proof

Step 1

Physiological Role of Vitamin B12 (Cyanocobalamin)

Vitamin $B_{12}$ (cyanocobalamin) is a cobalt-containing water-soluble vitamin required for DNA synthesis, erythropoiesis (maturation of red blood cells in the bone marrow), and normal myelin sheath synthesis in nerve cells.

Step 2

Deficiency Manifestation: Pernicious Anaemia

In the absence of Vitamin $B_{12}$ (or lack of intrinsic factor required for its absorption in the terminal ileum), erythroblasts fail to proliferate properly, resulting in megaloblastic/pernicious anaemia characterized by a severe deficiency of mature functional red blood cells (RBC deficiency) and low haemoglobin count.

Step 3

Review of Other B-Complex Vitamins in NCERT

- Vitamin $B_1$ (Thiamine): Causes Beri-beri. - Vitamin $B_2$ (Riboflavin): Causes Cheilosis (cracked lips and corners of mouth), digestive disorders, burning sensation of skin. - Vitamin $B_6$ (Pyridoxine): Causes Convulsions.

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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 1

✓ 100% Correct

Verdict & Scientific Reason:

Verbatim NCERT deficiency disease match: Vitamin $B_{12}$ deficiency causes RBC deficiency (pernicious anaemia).

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Why this is airtight: None; textbook biochemistry recall.

2 2

✗ Incorrect

Verdict & Scientific Reason:

Vitamin B6 deficiency results in convulsions, not RBC deficiency in NCERT.

⚠️

Student Fallacy (Why candidates pick this trap): Confusing B6 with B12.

3 3

✗ Incorrect

Verdict & Scientific Reason:

Vitamin B1 deficiency causes Beri-beri.

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Student Fallacy (Why candidates pick this trap): Associating all B-vitamins with anaemia.

4 4

✗ Incorrect

Verdict & Scientific Reason:

Vitamin B2 deficiency causes Cheilosis.

⚠️

Student Fallacy (Why candidates pick this trap): Confusing riboflavin with cyanocobalamin.

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NTA Trap Alert: B-Complex Vitamins Differentiation Trap

Questions on B-complex vitamins test specific disease associations from NCERT: - $B_1 \to$ Beri-beri - $B_2 \to$ Cheilosis - $B_6 \to$ Convulsions - $B_{12} \to$ Pernicious anaemia (RBC deficiency)

🛡️ How to avoid the -1 mark: RBC deficiency = Pernicious Anaemia

\implies

Vitamin

B_{12}

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Core NEET Syllabus Standard

NCERT Chemistry · Biomolecules Standard Benchmark

Core Scientific Principle Tested:

"Vitamin B12 deficiency leads to pernicious anaemia, characterized by RBC deficiency in haemoglobin."

Syllabus Focus: Vitamins (Classification and Deficiency Diseases)

✓ Core NEET UG Syllabus Anchor Syllabus & Academic Standards ↗

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NEET 2021 Chemistry Question 76 Solution

Question

The 30-Second Exam Hall Shortcut: ⚡ B12 Deficiency = Pernicious Anaemia (RBC Deficiency)

Step-by-Step Rigorous Workflow & Mathematical Proof

Physiological Role of Vitamin B12 (Cyanocobalamin)

Deficiency Manifestation: Pernicious Anaemia

Review of Other B-Complex Vitamins in NCERT

360° Option Elimination Engine Key Feature

NTA Trap Alert: B-Complex Vitamins Differentiation Trap

Core NEET Syllabus Standard

Ready to attempt under real exam pressure?

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