Select the correct statements about a cockroach.

Options

A. The sclerites joined to each other by a thick , hard and non - flexible arthrodial membrane.
B. Each thoracic segments bears a pair of flying wings.
C. In the cockroach, the fat body, nephrocytes and urecose glands helps in excretion.
D. A characteristic mushroom gland is present in the `4-6^(th)` abdominal segments.

Answer

To determine the correct statements about a cockroach, let's analyze each statement provided:

1. **Statement 1**: "The sclerite joins to each other by the thick hard and non-flexible arthrodial membrane."
- **Analysis**: This statement is incorrect. In a cockroach, the sclerites (the hardened plates of the exoskeleton) are joined by thin, flexible arthrodial membranes, which allow for movement. The arthrodial membrane is not thick and hard; rather, it is flexible.

2. **Statement 2**: "Each thoracic segment bears a pair of flying wings."
- **Analysis**: This statement is also incorrect. While the thorax of a cockroach has three segments (prothorax, mesothorax, and metathorax), only the mesothorax and metathorax bear a pair of wings. The prothorax does not have wings. Therefore, it is incorrect to say that each thoracic segment bears a pair of flying wings.

3. **Statement 3**: "In the cockroach, the fat body, nephrocytes, uricose gland help in excretion."
- **Analysis**: This statement is correct. The fat body, nephrocytes, and uricose glands are involved in the excretory system of the cockroach. They play a crucial role in the removal of waste materials from the body.

4. **Statement 4**: "Characteristic mushroom gland is present in the 4th to 6th abdominal segments."
- **Analysis**: This statement is also correct. The mushroom glands, which are involved in the reproductive system, are indeed located in the 4th to 6th abdominal segments of the cockroach.

**Conclusion**: The correct statements about a cockroach are:
- Statement 3: "In the cockroach, the fat body, nephrocytes, uricose gland help in excretion."
- Statement 4: "Characteristic mushroom gland is present in the 4th to 6th abdominal segments."

**Final Answer**: The correct statements are 3 and 4.

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