Q.137 Zoology ⭐ 360° Option Elimination Active

NEET 2025 Zoology Question 137 Solution

Topic: Biomolecules · Official NTA Booklet Code 45

Question

Match List I with List II. List I: A. Adenosine; B. Adenylic acid; C. Adenine; D. Alanine. List II: I. Nitrogen base; II. Nucleotide; III. Nucleoside; IV. Amino acid. Choose the option with all correct matches.

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Verified Against NTA Final Answer Key

Option (3) : A-III, B-II, C-I, D-IV

📚 Biomolecules Easy

📋 Given Parameters & Problem Setup

List I (Biomolecules) A. Adenosine, B. Adenylic acid, C. Adenine, D. Alanine

List II (Chemical Classes) I. Nitrogen base, II. Nucleotide, III. Nucleoside, IV. Amino acid

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The 30-Second Exam Hall Shortcut: ⚡ Adenine Derivative Nomenclature Fingerprint

⏱️ Save ~25 seconds

Adenine = Nitrogen base (I); Adenosine = Base + Sugar = Nucleoside (III); Adenylic acid = Base + Sugar + Phosphate = Nucleotide (II); Alanine = Amino acid (IV)! Match: A-III, B-II, C-I, D-IV!

1 Apply biomolecule nomenclature rules from NCERT:

2 - Adenine: Heterocyclic purine nitrogenous base (C -> I).

3 - Adenosine: Adenine bonded to ribose sugar via N-glycosidic bond -> Nucleoside (A -> III).

4 - Adenylic acid (AMP): Adenosine esterified with phosphate group -> Nucleotide (B -> II).

5 - Alanine: Alpha-amino acid with methyl (-CH₃) group as R-group (D -> IV).

6 Direct matching code: A-III, B-II, C-I, D-IV (Option 3)!

7 Solved in under 5 seconds!

🛡️

Why You Can 100% Trust This Shortcut: Biomolecules Acid-Soluble vs Acid-Insoluble Fractions (NCERT Biology · Biomolecules: Trichloroacetic acid extraction).

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Step-by-Step Rigorous Workflow & Mathematical Proof

Step 1

Chemical Definitions of the Biomolecules

Understanding the hierarchical composition of nucleic acid building blocks and amino acids:

• A. Adenosine: Formed when the purine base adenine is covalently linked to a pentose sugar (ribose or deoxyribose) through an N-glycosidic linkage. It is a Nucleoside. Hence, A matches III.
• B. Adenylic acid (Adenosine monophosphate / AMP): Formed when a phosphate group is esterified to the 5'-OH of the pentose sugar in adenosine. It is a Nucleotide. Hence, B matches II.
• C. Adenine: A substituted purine (6-aminopurine) consisting of a heterocyclic carbon-nitrogen double ring. It is a free Nitrogen base. Hence, C matches I.
• D. Alanine: An organic molecule containing an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a methyl group (-CH₃) attached to the $\alpha$ -carbon. It is an Amino acid. Hence, D matches IV.

Step 2

Formulating the Matching Code

Pairing the components:

• A -> III (Adenosine = Nucleoside)
• B -> II (Adenylic acid = Nucleotide)
• C -> I (Adenine = Nitrogen base)
• D -> IV (Alanine = Amino acid)

Step 3

Conclusion

The unambiguous combination is A-III, B-II, C-I, D-IV, corresponding to Option (3).

\text{Code: } A\text{-III}, \; B\text{-II}, \; C\text{-I}, \; D\text{-IV}

⭐

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. Assigns amino acid to adenylic acid and nitrogen base to alanine.

⚠️

Student Fallacy (Why candidates pick this trap): Confusing nucleotide acids with amino acids.

2 B

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Matches adenine with amino acid and alanine with nitrogen base.

⚠️

Student Fallacy (Why candidates pick this trap): Swapping adenine and alanine due to similar names.

3 C

✓ 100% Correct

Verdict & Scientific Reason:

100% correct. Correctly identifies nucleoside, nucleotide, nitrogen base, and amino acid.

💡

Why this is airtight: None; clean biochemical definitions.

4 D

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Inverts adenosine (nucleoside) and adenylic acid (nucleotide).

⚠️

Student Fallacy (Why candidates pick this trap): Failing to remember that "-ylic acid" signifies the phosphate-bearing nucleotide.

⚠️

NTA Trap Alert: Adenosine vs Adenylic Acid vs Adenine vs Alanine

The four "A" names are notorious for confusing unprepared students: AdenINE = Base alone; AdenoSINE = Base + Sugar (Nucleoside); AdenyLIC ACID = Base + Sugar + Phosphate (Nucleotide); ALANINE = Amino acid!

🛡️ How to avoid the -1 mark: Suffix check: -ine (base), -sine (nucleoside), -ylic acid (nucleotide), Alanine (amino acid).

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Core NEET Syllabus Standard

NEET Biology Core Syllabus · Biomolecules Standard Benchmark

Core Scientific Principle Tested:

"Adenine is a nitrogen base, adenosine is a nucleoside, adenylic acid is a nucleotide, and alanine is an amino acid."

Syllabus Focus: How to Analyse Chemical Composition? · Nucleic Acids & Amino Acids

✓ Core NEET UG Syllabus Anchor Syllabus & Academic Standards ↗

Base = AdenINE; Side = AdenoSINE; Tide = AdenyLIC acid; Protein unit = ALANINE!

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Classification & Functions of Biomolecules (Proteins, Polysaccharides & Secondary Metabolites)

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NEET 2025 Zoology Question 137 Solution

Question

The 30-Second Exam Hall Shortcut: ⚡ Adenine Derivative Nomenclature Fingerprint

Step-by-Step Rigorous Workflow & Mathematical Proof

Chemical Definitions of the Biomolecules

Formulating the Matching Code

Conclusion

360° Option Elimination Engine Key Feature

NTA Trap Alert: Adenosine vs Adenylic Acid vs Adenine vs Alanine

Core NEET Syllabus Standard

Ready to attempt under real exam pressure?

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