Nucleated RBC is found in:

Options

A. Man
B. Rat
C. Rabbit
D. Frog

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks where nucleated red blood cells (RBCs) are found. We need to identify which organisms have RBCs that contain a nucleus.

2. **Analyzing the Options**: The options provided typically include various animals. We will evaluate each option to determine if nucleated RBCs are present.

3. **Option 1: Mammals**: In mammals, red blood cells are known to be anucleated, meaning they do not contain a nucleus. Therefore, this option is incorrect.

4. **Option 2: Birds**: Similar to mammals, birds also have nucleated RBCs. However, the question may not include birds explicitly, so we will continue evaluating the other options.

5. **Option 3: Rabbit**: Rabbits are mammals, and as previously mentioned, mammalian red blood cells do not have a nucleus. Thus, this option is also incorrect.

6. **Option 4: Frog**: Frogs are amphibians, and they possess nucleated red blood cells. This means that their RBCs do contain a nucleus, which carries DNA. Therefore, this option is correct.

7. **Conclusion**: Based on the analysis, the correct answer to the question is that nucleated RBCs are found in frogs.

**Final Answer**: Nucleated RBCs are found in frogs.

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