These cells of adult animals don't divide

Options

A. Liver cells
B. Heart cells
C. Nerve cells
D. 2 and 3

Answer

To answer the question "These cells of adult animals don't divide," we will analyze the options provided: liver cells, heart cells, nerve cells, and the option that includes both heart and nerve cells.

### Step-by-Step Solution:

1. **Identify the Cell Types**: We have three types of cells to consider:
- Liver cells
- Heart cells
- Nerve cells

2. **Evaluate Liver Cells**:
- Liver cells (hepatocytes) are known to have a high regenerative capacity. They can divide and regenerate even in adults.
- **Conclusion**: Liver cells do divide in adult animals.

3. **Evaluate Heart Cells**:
- Heart cells, specifically cardiomyocytes, can divide during embryonic development. However, after birth, these cells lose their ability to divide.
- **Conclusion**: Heart cells do not divide in adult animals.

4. **Evaluate Nerve Cells**:
- Nerve cells (neurons) are specialized cells that generally do not divide. They lack centrioles, which are necessary for cell division.
- **Conclusion**: Nerve cells do not divide in adult animals.

5. **Combine Findings**:
- Since liver cells divide, they are not part of the answer. However, both heart cells and nerve cells do not divide in adult animals.
- Therefore, the correct answer is option four, which states "two and three" (heart cells and nerve cells).

### Final Answer:
The cells of adult animals that do not divide are heart cells and nerve cells (option four: two and three).

---