Q.175 Zoology ⭐ 360° Option Elimination Active

NEET 2025 Zoology Question 175 Solution

Topic: Structural Organisation in Animals · Official NTA Booklet Code 45

Question

Frogs respire in water by skin and buccal cavity and on land by skin, buccal cavity and lungs. Choose the correct answer from the following:

(1)The statement is true for water but false for land
(2)The statement is true for both the environment
(3)The statement is false for water but true for land
(4)The statement is false for both the environment

✓

Verified Against NTA Final Answer Key

Option (3) : The statement is false for water but true for land

📚 Structural Organisation in Animals Medium

📋 Given Parameters & Problem Setup

Proposition Given Frogs respire in water by skin and buccal cavity and on land by skin, buccal cavity and lungs.

Target Evaluation Truth value across both aquatic and terrestrial environments

⚡

The 30-Second Exam Hall Shortcut: ⚡ Frog Respiration Medium Diagnostic

⏱️ Save ~25 seconds

In water, frog respires ONLY by SKIN (cutaneous respiration; mouth and nostrils are tightly sealed)! On land, it respires by SKIN, BUCCAL CAVITY, and LUNGS! Thus, the claim is FALSE for water, but TRUE for land!

1 Check NCERT Section 7.4.2 (Frog - Respiratory System) verbatim:

2 "In water, skin acts as aquatic respiratory organ (cutaneous respiration). Dissolved oxygen in the water is exchanged through the skin by diffusion."

3 - Notice: In water, the buccal cavity does NOT participate (the mouth is closed to prevent water entry into lungs). Thus, claiming "in water by skin and buccal cavity" is FALSE!

4 "On land, the buccal cavity, skin and lungs act as the respiratory organs."

5 - Thus, claiming "on land by skin, buccal cavity and lungs" is TRUE!

6 Conclusion: The statement is false for water but true for land (Option 3)!

7 Select Option (3)!

🛡️

Why You Can 100% Trust This Shortcut: Cockroach Mouthparts & Nervous System Ganglia (NCERT Biology · Structural Organisation in Animals: Biting and chewing type).

📐

Step-by-Step Rigorous Workflow & Mathematical Proof

Step 1

Aquatic Respiration in Rana tigrina (Water Mode)

When submerged underwater or during aestivation/hibernation:

• Cutaneous respiration is the exclusive mode of respiration in water.
• The skin is highly vascularized, thin, and kept perpetually moist by mucus glands.
• Dissolved oxygen in the aquatic medium diffuses directly across the moist epidermis into cutaneous capillaries, while carbon dioxide diffuses out.
• The mouth and external nares remain tightly closed underwater; buccal ventilation and pulmonary ventilation do not occur in water.
• Therefore, the claim that frogs respire in water by "skin and buccal cavity" is factually FALSE.

Step 2

Terrestrial Respiration in Rana tigrina (Land Mode)

When on land, the frog utilizes three integrated anatomical modalities:

• 1. Cutaneous respiration: Oxygen continues to diffuse through the moist skin.
• 2. Buccopharyngeal respiration: The lining of the buccal cavity is highly vascular; rhythmic raising and lowering of the hyoid apparatus draws air through external nares into the buccal cavity for gas exchange.
• 3. Pulmonary respiration: A pair of elongated, pink, sac-like lungs perform pulmonary ventilation.
• Therefore, the claim that on land frogs respire by "skin, buccal cavity and lungs" is completely TRUE.

Step 3

Synthesizing the Final Verdict

Comparing the two clauses of the test statement:

• Clause 1 (Water): "Frogs respire in water by skin and buccal cavity" -> FALSE.
• Clause 2 (Land): "...and on land by skin, buccal cavity and lungs" -> TRUE.
• Hence, the proposition is false for water but true for land.

Step 4

Conclusion

The correct option is Option (3): The statement is false for water but true for land.

\text{Water: Cutaneous ONLY (False)} \quad \text{vs} \quad \text{Land: Skin + Buccal + Lungs (True)}

⭐

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. Reverses the veracity for both environments.

⚠️

Student Fallacy (Why candidates pick this trap): Thinking buccal cavity works underwater and lungs are absent on land.

2 B

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. Fails to recognize that buccal respiration cannot happen underwater without drowning the respiratory passages.

⚠️

Student Fallacy (Why candidates pick this trap): Assuming the frog uses buccal pumping underwater.

3 C

✓ 100% Correct

Verdict & Scientific Reason:

100% correct. Accurately pinpoints that in water only skin respires, while on land skin, buccal cavity, and lungs all function.

💡

Why this is airtight: None; pristine physiological mastery of amphibian respiration.

4 D

✗ Incorrect

Verdict & Scientific Reason:

Incorrect. The land description is a word-for-word match with NCERT.

⚠️

Student Fallacy (Why candidates pick this trap): Denying the tripartite respiratory mechanism on land.

⚠️

NTA Trap Alert: Water Breathing: Buccal Cavity is INACTIVE

Students often generalize: "frogs have 3 types of respiration, so they use them everywhere". In water, the frog can ONLY use cutaneous respiration (skin). Using the buccal cavity would swallow water into lungs!

🛡️ How to avoid the -1 mark: Water = Skin ONLY. Land = Skin + Buccal + Lungs.

📖

Core NEET Syllabus Standard

NEET Biology Core Syllabus · Structural Organisation in Animals Standard Benchmark

Core Scientific Principle Tested:

"In water, only skin performs respiration; on land, buccal cavity, skin, and lungs act as respiratory organs."

Syllabus Focus: Frog Anatomy · Respiratory System

✓ Core NEET UG Syllabus Anchor Syllabus & Academic Standards ↗

Water = Skin Solo; Land = Trio in Demand (Skin, Buccal, Lungs)!

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NEET 2025 Zoology Question 175 Solution

Question

The 30-Second Exam Hall Shortcut: ⚡ Frog Respiration Medium Diagnostic

Step-by-Step Rigorous Workflow & Mathematical Proof

Aquatic Respiration in Rana tigrina (Water Mode)

Terrestrial Respiration in Rana tigrina (Land Mode)

Synthesizing the Final Verdict

Conclusion

360° Option Elimination Engine Key Feature

NTA Trap Alert: Water Breathing: Buccal Cavity is INACTIVE

Core NEET Syllabus Standard

Ready to attempt under real exam pressure?

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