The circulatory system of cockroach

Options

A. is present on dorsal side and has 3 chambers of heart in abdominal region
B. is present on ventral side and has 10 abdominal and 3 thoracic chambers of heart
C. is present on ventral side and has 13 chambers of heart in abdominal region
D. is present on dorsal side and has 10 abdominal and 3 thoracic chambers of heart

Answer

### Step-by-Step Solution:

1. **Understanding the Circulatory System of Cockroach**:
- The circulatory system of a cockroach is an open type of circulatory system. This means that the blood is not always contained within blood vessels but flows freely through cavities.

2. **Location of the Heart**:
- The heart of the cockroach is located mid-dorsally, which means it is situated on the upper side of the body.

3. **Chambers of the Heart**:
- The heart of a cockroach is segmented and consists of a total of 13 chambers. These chambers are differentiated into:
- 3 thoracic chambers (located in the thorax)
- 10 abdominal chambers (located in the abdomen)

4. **Evaluating the Options**:
- **Option 1**: States that the heart is on the dorsal side and has 3 chambers in the abdominal region. This is incorrect because the heart has 13 chambers, not just 3.
- **Option 2**: States that it is on the ventral side and has 10 abdominal and 3 thoracic chambers. This is incorrect because the heart is on the dorsal side, not the ventral side.
- **Option 3**: States that it is on the dorsal side and has 10 abdominal and 3 thoracic chambers. This is incorrect because it misstates the number of abdominal chambers.
- **Option 4**: Correctly states that the heart is on the dorsal side and consists of 10 abdominal and 3 thoracic chambers, totaling 13 chambers.

5. **Conclusion**:
- The correct answer is **Option 4**: The heart of the cockroach is present on the dorsal side and has a total of 13 chambers (10 abdominal and 3 thoracic).