Question

Study the following regarding circulatory system of cockroach and identify the correct option
Statement I : The cockroach heart is a tubular structure with 13 chambers.
Statement II : Haemolymph in cockroach plays a role in oxygen transportation.

• A. Both statements I and II are correct.
• B. Statement I is correct, but statement II is incorrect.
• C. Statement I is incorrect, but statement II is correct.
• D. Both statements I and II are incorrect.

Hint:

The open circulatory system of insects like cockroaches uses haemolymph for nutrient and waste transport, but their respiratory system is distinct. Oxygen is delivered directly to cells via the tracheal system, making haemolymph's role in oxygen transport negligible due to the absence of respiratory pigments.

Answer 1

The Correct Option is B

Step 1: Understand the question.
The question asks to evaluate two statements about the circulatory system of a cockroach and choose the correct option that describes their validity. Step 2: Evaluate Statement I.
Statement I: The cockroach heart is a tubular structure with 13 chambers.
The circulatory system in cockroaches is of the open type. The heart is indeed a long, dorsal, tubular structure that extends along the mid-dorsal line of the thorax and abdomen. It is typically composed of 13 segmentally arranged, funnel-shaped chambers. Haemolymph (insect blood) enters these chambers through ostia (small openings). Therefore, Statement I is Correct. Step 3: Evaluate Statement II.
Statement II: Haemolymph in cockroach plays a role in oxygen transportation.
In cockroaches and most other insects, oxygen is not transported by the haemolymph. Instead, oxygen is directly delivered to the tissues and cells through a network of tracheal tubes that open to the outside via spiracles. The haemolymph, which is the circulatory fluid, primarily transports nutrients, hormones, and metabolic wastes, but it generally lacks respiratory pigments (like hemoglobin) that are necessary for efficient oxygen transport. Therefore, Statement II is Incorrect. Step 4: Conclude the correct option.
Based on the evaluation, Statement I is correct, and Statement II is incorrect. This corresponds to option (2). The final answer is $\boxed{\text{Statement I is correct, but statement II is incorrect.}}$.