Chapter Exam

Chapter 4: Organ and Organ Systems in Animals — Online MCQ Test

Q: Which organ in the earthworm acts as the primary respiratory surface?

Answer: A. Moist skin — Earthworms undergo cutaneous respiration, where oxygen diffuses through their thin, moist skin.

Q: How many segments are present in the body of an adult earthworm?

Answer: B. 100-120 — An adult earthworm typically consists of 100 to 120 segments arranged in a linear fashion.

Q: What is the function of typhlosole in the intestine of an earthworm?

Answer: B. To increase the surface area for absorption — The typhlosole is an internal fold of the intestine that significantly increases the surface area for nutrient absorption.

Q: Why is the circulatory system of an earthworm classified as 'closed'?

Answer: B. Blood is pumped by a heart into vessels — A closed circulatory system means the blood is confined within heart and blood vessels, never entering body cavities.

Q: In cockroach anatomy, the 'alary muscles' are associated with:

Answer: B. Circulation — Alary muscles are fan-shaped muscles that help maintain the circulation of hemolymph through the heart chambers.

ZOOLOGY · CLASS 11th · Tamil Nadu State Board

Practice Chapter 4: Organ and Organ Systems in Animals with a free chapter-wise online MCQ test for Tamil Nadu State Board CLASS 11th ZOOLOGY. This chapter covers: Focusing on animal morphology and anatomy this chapter details model organisms such as earthworm cockroach and frog. Students compare digestive respiratory circulatory nervous and.... AI-generated questions from basic to board-exam level, with instant results and explanations.

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Chapter 4: Organ and Organ Systems in Animals — Important Questions & Answers (FAQ)

Frequently asked questions from Tamil Nadu State Board CLASS 11th ZOOLOGY — Chapter 4: Organ and Organ Systems in Animals, with answers and explanations. These are sample questions; the exam has its own separate question set.

Which organ in the earthworm acts as the primary respiratory surface?

A. Moist skin ✓
B. Gills
C. Trachea
D. Lungs

Answer: A. Moist skin
Earthworms undergo cutaneous respiration, where oxygen diffuses through their thin, moist skin.

How many segments are present in the body of an adult earthworm?

A. 50-75
B. 100-120 ✓
C. 150-180
D. 200-250

Answer: B. 100-120
An adult earthworm typically consists of 100 to 120 segments arranged in a linear fashion.

What is the function of typhlosole in the intestine of an earthworm?

A. To store undigested food
B. To increase the surface area for absorption ✓
C. To aid in locomotion
D. To secrete enzymes

Answer: B. To increase the surface area for absorption
The typhlosole is an internal fold of the intestine that significantly increases the surface area for nutrient absorption.

Why is the circulatory system of an earthworm classified as 'closed'?

A. Blood flows in open sinuses
B. Blood is pumped by a heart into vessels ✓
C. The heart has four chambers
D. It lacks hemoglobin

Answer: B. Blood is pumped by a heart into vessels
A closed circulatory system means the blood is confined within heart and blood vessels, never entering body cavities.

In cockroach anatomy, the 'alary muscles' are associated with: