Which one of the following is the true description about an animal concerned? [2008]

a)
Earthworm - The alimentary canal consists of a sequence of pharynx, oesophagus, stomach, gizzard and intestine

b)
Frog - Body divisible into three regions - head, neck and trunk

c)
Rat - Left kidney is slightly higher in position than the right one

d)
Cockroach - 10 pairs of spiracles (2 pairs on thorax and 8 pairs on abdomen)

Correct answer is option 'D'. Can you explain this answer?

Question

Which one of the following is the true description about an animal concerned? [2008]

a)
Earthworm - The alimentary canal consists of a sequence of pharynx, oesophagus, stomach, gizzard and intestine
b)
Frog - Body divisible into three regions - head, neck and trunk
c)
Rat - Left kidney is slightly higher in position than the right one
d)
Cockroach - 10 pairs of spiracles (2 pairs on thorax and 8 pairs on abdomen)

Correct answer is option 'D'. Can you explain this answer?

Answer

The respiratory system of cockroach consists of trachea, tracheoles and spiracles. The main trachea trunks open to the exterior on body surface through 10 pairs of segmentally arranged spiracles 2 pairs of spiracles are thoracic ( one between pro and mesothrax and other between meso and metathorax ). Eight pairs of spiracles are abdominal ( one pair in each of the first and abdominal segments).
Therefore, option 'D' is the correct answer..

Answer

Cockroach>10 pairs of spiracles 2 in thorax and 8 in abdomen.. spiracles are helps in respiration in cockroaches..

Answer

Correct Answer Analysis:

Option D: Cockroach - 10 pairs of spiracles (2 pairs on thorax and 8 pairs on abdomen)

- A spiracle is a respiratory opening in insects, through which air enters and exits the body. The number and location of spiracles can vary among different insect species.

- Cockroaches, including the common household cockroach, have spiracles for respiration. The spiracles are located on the thorax (the middle part of the body) and the abdomen (the hind part of the body).

- Cockroaches have two pairs of spiracles on the thorax, which allow air to enter and exit. They also have eight pairs of spiracles on the abdomen, which serve the same purpose.

- The presence of spiracles is an adaptation for efficient respiration in cockroaches, allowing them to take in oxygen and release carbon dioxide.

Option A: Earthworm - The alimentary canal consists of a sequence of pharynx, esophagus, stomach, gizzard, and intestine

- The alimentary canal, also known as the digestive tract, is the pathway through which food passes in animals.

- In earthworms, the alimentary canal consists of several parts, including the pharynx, esophagus, stomach, gizzard, and intestine.

- The pharynx is the muscular part of the throat that helps in swallowing food. The esophagus is the tube that connects the pharynx to the stomach.

- The stomach is where food is partially digested, and the gizzard is a muscular part of the stomach that helps grind the food.

- The intestine is responsible for the absorption of nutrients from the digested food.

Option B: Frog - Body divisible into three regions - head, neck, and trunk

- Frogs have a distinct body structure with three main regions: the head, neck, and trunk.

- The head contains the brain, eyes, ears, mouth, and other sensory organs.

- The neck connects the head to the trunk and allows for movement and flexibility.

- The trunk is the main part of the body and contains the internal organs, such as the heart, lungs, and digestive system.

- This division of the body into three regions is a characteristic feature of frogs and helps in their locomotion and overall body function.

Option C: Rat - Left kidney is slightly higher in position than the right one

- In rats, the left kidney is positioned slightly higher than the right kidney.

- This anatomical difference is common in many mammals, including humans, where the left kidney is positioned slightly higher than the right kidney.

- The kidneys are responsible for filtering waste products from the blood and regulating water and electrolyte balance in the body.

- The difference in position between the left and right kidneys is a normal variation in anatomy and does not have significant functional implications.

Conclusion: Among the given options, the true description is option D, which states that a cockroach has 10 pairs of spiracles, with 2 pairs on the thorax and 8 pairs on the abdomen. This adaptation allows cockroaches to efficiently exchange gases and respire.

Top Courses for NEETView all

Biology Class 11

Daily Test for NEET Preparation

NEET Mock Test Series 2025

Topic-wise MCQ Tests for NEET

Physics Class 11

Top Courses for NEET

Top Courses for NEET

Suggested Free Tests

Related Content

About NEET

NEET Preparation Material

How to Prepare for NEET Exam?

NCERT Based Study Material

NEET Mock Tests

Other Popular Exams

Company