Question

How many pairs of spiracles is present on the surface of cockroach? (a) 5 pairs (b) 15 pairs (c) 10 pairs (d) 20 pairs

Short answer

The correct answer is (c) 10 pairs.

Step-by-step solution

Recall the Biological Fact

Recall that the number of pairs of spiracles in a cockroach is a biological fact. A pair of spiracles is present in each taergum (segment) in a cockroach.

Identify the Correct Answer

Recognize the correct option based on this information. The cockroach, being an insect, has 10 segments in its thorax and abdomen segments combined, hence 10 pairs of spiracles.

Key concepts

Cockroach Anatomy

Cockroach anatomy is fascinating and quite unique compared to other animals. Cockroaches have three main body sections: the head, thorax, and abdomen. On its head, a cockroach has compound eyes, antennae, and mouthparts designed for chewing.

The thorax consists of three segments and is where the cockroach's legs and wings are attached. Each segment of the thorax has a pair of legs, and the two rear thoracic segments may have wings.

The abdomen, the largest section, is made up of several segments each containing various systems vital for survival, such as its digestive system, excretory system, and parts of the reproductive system. It's crucial to the insect's respiratory function as well, housing most of a cockroach's spiracles, which are small openings used for breathing.

Insect Respiratory System

The insect respiratory system doesn't work like the human system. Insects breathe through spiracles, which are tiny openings on the surface of their bodies. Cockroaches specifically have 10 pairs of these spiracles. These are strategically located across their thorax and abdomen.

Air enters the spiracles and travels through a network of tubes called tracheae that distribute oxygen directly to tissues. The tracheal system is highly efficient for the insect's body size, providing direct oxygen access without the need for blood as a medium.

Nutrient delivery is also supported by this system, making it very effective despite the simplicity. It is, however, less adaptive to fluctuating oxygen needs than complex systems like those in mammals.

Biological Facts

Understanding a few key biological facts about cockroaches can help us appreciate their adaptability. For instance, cockroaches have a pair of spiracles in each of the 10 body segments across the thorax and abdomen. This makes for a total of 10 pairs of spiracles.

This distribution supports efficient respiration and contributes significantly to their survival in various habitats.

Cockroaches have survived millions of years due to their less specialized and generalized body functions. They can thrive in diverse environments, eat a variety of foods, and resist certain environmental pressures.

• They have been around for over 300 million years.
• Cockroaches can hold their breath to prevent water loss, showcasing their adaptability.
• Their nutritional requirements are minimal.

These biological traits enable them to be incredibly resilient and prolific survivors.