From the given list, how many are unpaired structures of a cockroach ?
Tergites, Labium, Hypopharynx, Tegmina, Genital pouch, Labrum, Mandible
(a) Six
(b) Seven
(c) Five
(d) Four

Options

A. Six
B. Seven
C. Five
D. Four

Answer

To determine how many unpaired structures are present in a cockroach from the given list, we will analyze each structure one by one.

1. **Tergites**: These are the dorsal plates of the segments of the cockroach's exoskeleton. There are multiple tergites, and they are paired. Thus, this is a paired structure.

2. **Labium**: This is the lower lip of the cockroach, and it is a single structure. Therefore, it is unpaired.

3. **Hypopharynx**: This is a part of the mouth and is also a single structure. Hence, it is unpaired.

4. **Tegmina**: These are the forewings of the cockroach. There are two tegmina, so they are paired structures.

5. **Genital pouch**: This is part of the reproductive system and is a single structure. Thus, it is unpaired.

6. **Labrum**: This is the upper lip of the cockroach, and it is a single structure. Therefore, it is unpaired.

7. **Mandible**: These are the jaw parts of the cockroach, and there are two mandibles, making them paired structures.

Now, let's summarize the findings:

- Unpaired structures: Labium, Hypopharynx, Genital pouch, Labrum (4 structures)
- Paired structures: Tergites, Tegmina, Mandible (3 structures)

Thus, the total number of unpaired structures in the cockroach is **4**.

The correct answer is **(d) Four**.