In Pheretima, there are red coloured round bodies in `4^(th),5^(th)` and `6^(th)` segments above the alimentary canal. They are believed to be involved in

Options

A. respiration
B. digestion
C. reproduction
D. leucocyte production

Explanation

To answer the question regarding the red colored round bodies found in the 4th, 5th, and 6th segments of Pheretima (earthworm), we can follow these steps:

### Step 1: Identify the Organism
Pheretima is commonly known as the earthworm. Understanding its biological classification helps in identifying its anatomical features.

**Hint:** Remember that Pheretima is a type of annelid, which is a segmented worm.

### Step 2: Locate the Red Bodies
The question specifies that these red-colored round bodies are located in the 4th, 5th, and 6th segments above the alimentary canal.

**Hint:** Focus on the segmentation of the earthworm and where these structures are positioned.

### Step 3: Understand the Function of These Bodies
These red bodies are referred to as blood glands. They are involved in the synthesis of specific components related to the circulatory system.

**Hint:** Think about the role of blood in the body and what components are crucial for its function.

### Step 4: Identify the Specific Role of Blood Glands
The blood glands in Pheretima are primarily involved in the production of leukocytes (white blood cells) and hemoglobin. Hemoglobin in earthworms is dissolved in the plasma rather than being contained within red blood cells.

**Hint:** Consider the importance of leukocytes in the immune system and hemoglobin in oxygen transport.

### Step 5: Eliminate Other Options
The question provides multiple choices: respiration, digestion, reproduction, and leukocyte production. Since the blood glands are specifically associated with leukocyte production, we can eliminate the other options.

**Hint:** Review the functions of the earthworm's systems to determine which options are not applicable.

### Conclusion
Based on the analysis, the red colored round bodies in the 4th, 5th, and 6th segments of Pheretima are believed to be involved in leukocyte production.

**Final Answer:** The correct answer is leukocyte production.

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