Blood vessels in Pheretima, which have valves are

Options

A. dorsal
B. ventral
C. supra-oesophageal
D. lateral oesophageal

Explanation

To answer the question about which blood vessels in Pheretima (earthworm) have valves, we can analyze the types of blood vessels present in the organism. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Types of Blood Vessels
The main types of blood vessels in Pheretima are:
1. Dorsal blood vessel
2. Ventral blood vessel
3. Supraesophageal blood vessel
4. Lateral esophageal blood vessel

### Step 2: Function of Each Blood Vessel
- **Dorsal Blood Vessel**: This is a collecting blood vessel that collects blood from the segments of the earthworm. It runs along the dorsal side and has valves to prevent backflow of blood.
- **Ventral Blood Vessel**: This is primarily a distributing blood vessel located below the alimentary canal. It does not have valves.
- **Supraesophageal Blood Vessel**: This vessel collects blood from the stomach and gizzard but does not have valves.
- **Lateral Esophageal Blood Vessel**: This is also a collecting blood vessel but does not have valves.

### Step 3: Identify Which Blood Vessel Has Valves
From the analysis:
- The **Dorsal Blood Vessel** is the only one that has valves. Its function of collecting blood and preventing backflow necessitates the presence of valves.

### Conclusion
The blood vessel in Pheretima that has valves is the **Dorsal Blood Vessel**.

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