Q.147 Zoology ⭐ 360° Option Elimination Active

NEET 2026 Zoology Question 147 Solution

Topic: Evolution · Official NTA Booklet Code 50

Question

A population of diploid organisms is at Hardy-Weinberg equilibrium. If the frequency of allele A is 0.1, the frequency of AA is.

(1)0.01
(2)0.02
(3)0.10
(4)0.99

✓

Verified Against NTA Final Answer Key

Option (1) : 0.01

📚 Evolution Easy

📋 Given Parameters & Problem Setup

Condition Population at Hardy-Weinberg equilibrium

Allele Frequency of A (p) p = 0.1

Target Genotype Homozygous dominant (AA)

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The 30-Second Exam Hall Shortcut: ⚡ Hardy-Weinberg p² Rule

⏱️ Save ~40 seconds

Frequency of AA = p² = (0.1)² = 0.01!

1 Recall Hardy-Weinberg binomial expansion: p² + 2pq + q² = 1.

2 Here, frequency of allele A is p = 0.1.

3 Frequency of homozygous genotype AA is simply p².

4 Calculate: (0.1)² = 0.01.

5 Option (1) is 0.01. Done in 3 seconds!

🛡️

Why You Can 100% Trust This Shortcut: NCERT Biology · Evolution (Hardy-Weinberg Equilibrium: p² + 2pq + q² = 1 for genetic stability).

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Step-by-Step Rigorous Workflow & Mathematical Proof

Step 1

State the Hardy-Weinberg Principle

In a large, randomly mating diploid population where evolutionary forces (mutation, gene flow, genetic drift, natural selection) are absent, allele frequencies and genotype frequencies remain constant from generation to generation.

p^2 + 2pq + q^2 = 1

• p = frequency of dominant allele A.
• q = frequency of recessive allele a.
• p² = frequency of homozygous genotype AA.
• 2pq = frequency of heterozygous genotype Aa.
• q² = frequency of homozygous genotype aa.

Step 2

Calculate Frequency of Genotype AA

We are given that the frequency of allele A is $p = 0.1$ . To find the frequency of individuals possessing genotype AA:

\text{Frequency}(AA) = p^2 = (0.1)^2 = 0.01

• p² = 0.01 (or 1% of the population).

Step 3

Evaluate Options

Option (1) gives 0.01, which is exact. Option (2) gives 0.02. Option (3) gives 0.10 (allele frequency p). Option (4) gives 0.99. Option (1) is correct.

\text{Correct Value} = \mathbf{0.01} \implies \text{Option (1)}

• Matches official NTA final answer key Option A / (1).

⭐

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

✓ 100% Correct

Verdict & Scientific Reason:

100% mathematically and genetically accurate: $p^2 = (0.1)^2 = 0.01$ .

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Why this is airtight: None; straightforward population genetics calculation.

2 B

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Represents an arithmetic error multiplying 0.1 by 2 instead of squaring.

⚠️

Student Fallacy (Why candidates pick this trap): Calculating 2p instead of p².

3 C

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Confuses genotype frequency (p²) with allele frequency (p).

⚠️

Student Fallacy (Why candidates pick this trap): Reporting allele frequency p directly instead of genotype frequency.

4 D

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Subtracts 0.01 from 1.

⚠️

Student Fallacy (Why candidates pick this trap): Confusing genotype frequency with its complement.

⚠️

NTA Trap Alert: Allele Frequency vs Genotype Frequency

Allele frequency is p or q (single letter). Genotype frequency is p², 2pq, or q² (two letters: AA, Aa, or aa). Always square the allele frequency to find the homozygous genotype frequency!

🛡️ How to avoid the -1 mark: Genotype has two alleles, so take the allele frequency to the POWER OF TWO: (0.1)² = 0.01.

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Core NEET Syllabus Standard

NEET Biology Core Syllabus · Evolution Standard Benchmark

Core Scientific Principle Tested:

"In Hardy-Weinberg equilibrium, the frequency of homozygous dominant genotype AA is given by $p^2$ ."

Syllabus Focus: Hardy-Weinberg Principle

✓ Core NEET UG Syllabus Anchor Syllabus & Academic Standards ↗

Single letter is p, Double letters square thee: AA = p² = 0.01!

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NEET 2026 Zoology Question 147 Solution

Question

The 30-Second Exam Hall Shortcut: ⚡ Hardy-Weinberg p² Rule

Step-by-Step Rigorous Workflow & Mathematical Proof

State the Hardy-Weinberg Principle

Calculate Frequency of Genotype AA

Evaluate Options

360° Option Elimination Engine Key Feature

NTA Trap Alert: Allele Frequency vs Genotype Frequency

Core NEET Syllabus Standard

Ready to attempt under real exam pressure?

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