Which cell type does not divide in mammals after birth

Options

A. Neurons and osteocytes
B. Muscle cells
C. Germ cells
D. Nerve

Explanation

To answer the question "Which cell type does not divide in mammals after birth?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Cell Types**: We need to consider the different types of cells mentioned in the question: neurons, osteocytes, muscle cells, germ cells, and nerve cells.

2. **Understand Neurons**: Neurons are specialized cells of the nervous system. Once they are fully developed, they typically do not undergo cell division. This is because they have a complex structure and function that is not conducive to division.

3. **Understand Osteocytes**: Osteocytes are mature bone cells that originate from osteoblasts. Once they mature, they also do not divide. They maintain bone tissue but do not replicate.

4. **Consider Muscle Cells**: Muscle cells (myocytes) can undergo some degree of repair and regeneration, particularly in response to injury, but they do not divide in the same way that other cell types do.

5. **Examine Germ Cells**: Germ cells are involved in reproduction and do continue to divide, producing gametes (sperm and eggs).

6. **Conclusion**: Based on the characteristics of these cells, the two types that do not divide after birth in mammals are neurons and osteocytes.

### Final Answer:
Neurons and osteocytes do not divide in mammals after birth.

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