Assertion : RBCs are devoid of nucles in most of the mammals
Reason : Entire cytoplasm of RBCs is filled protein called haemoglobin.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false

Answer

To analyze the assertion and reason provided in the question, we will break down the statements step by step.

### Step 1: Understanding the Assertion
- **Assertion**: "RBCs are devoid of nucleus in most of the mammals."
- In most mammals, red blood cells (RBCs) do not have a nucleus. This is an important adaptation that allows them to carry more hemoglobin, which is essential for oxygen transport.

### Step 2: Understanding the Reason
- **Reason**: "Entire cytoplasm of RBCs is filled with a protein called hemoglobin."
- Hemoglobin is the protein responsible for oxygen transport in the blood. The cytoplasm of RBCs is primarily composed of hemoglobin, which enables them to carry a significant amount of oxygen.

### Step 3: Connecting Assertion and Reason
- The assertion states a fact about the structure of RBCs, while the reason explains why this structure is beneficial. The lack of a nucleus allows for more space in the cell for hemoglobin, which in turn enhances the cell's ability to transport oxygen.

### Step 4: Evaluating the Truth of the Statements
- Both the assertion and the reason are true statements. The assertion accurately describes the structure of RBCs in mammals, and the reason correctly explains the functional advantage of this structure.

### Step 5: Conclusion
- Since both the assertion and reason are true and the reason provides a correct explanation for the assertion, the answer to the question is that both statements are true, and the reason correctly explains the assertion.

### Final Answer
- The correct option is: **Both assertion and reason are true, and the reason is the correct explanation of the assertion.**

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