Question

Which of the following characteristics is incorrect with respect to cockroach ?

• A. A ring of gastric caeca is present at the junction of midgut and hind gut.
• B. Hypopharynx lies within the cavity enclosed by the mouth parts.
• C. In females, $7^{th}-9^{th}$ sterna together form a genital pouch.
• D. $10^{th}$ abdominal segment in both sexes, bears a pair of anal cerci.

Answer 1

The Correct Option is A

The question provided is about identifying a characteristic of cockroaches that is mentioned incorrectly. Let's evaluate each option to determine which statement is inaccurate:

1. A ring of gastric caeca is present at the junction of midgut and hind gut: This statement is incorrect because in cockroaches, the gastric caeca actually open at the junction between the foregut and midgut, not between the midgut and hindgut. Thus, this statement does not accurately describe the anatomical structure of cockroaches.
2. Hypopharynx lies within the cavity enclosed by the mouth parts: This statement is correct. The hypopharynx is a part of the mouth structure in cockroaches and is located within the cavity formed by various mouthparts such as the mandibles and maxillae.
3. In females, $7^{th}-9^{th}$ sterna together form a genital pouch: This is true. In female cockroaches, the 7th to 9th sterna form a collective structure known as the genital pouch, an important aspect of their reproductive anatomy.
4. $10^{th}$ abdominal segment in both sexes, bears a pair of anal cerci: This statement is accurate. Cockroaches have a pair of sensory appendages called anal cerci originating from the 10th abdominal segment in both males and females.

After evaluating all options, the incorrect characteristic regarding cockroaches is the first statement, which concerns the location of the gastric caeca.