Which is immortal?

Options

A. Plasma Cell
B. Germ Cell
C. Brain Cell
D. Kidney Cell

Answer

To determine which cell type is considered immortal from the given options (plasma cell, germ cell, brain cell, kidney cell), we can analyze each option step by step:

### Step-by-Step Solution:

1. **Understanding Immortality in Cells**:
- Immortal cells are those that can divide indefinitely and do not undergo senescence (aging) like most other cells.

2. **Analyzing Each Option**:
- **Option A: Plasma Cell**:
- Plasma cells are derived from B lymphocytes and are responsible for producing antibodies. However, they have a finite lifespan and eventually die after fulfilling their function.

- **Option B: Germ Cell**:
- Germ cells are the precursors to sperm and egg cells. They are responsible for transmitting genetic material from parents to offspring. Germ cells can divide and give rise to new generations, thus maintaining their lineage indefinitely. This characteristic makes them immortal in the context of reproduction.

- **Option C: Brain Cell**:
- Brain cells, or neurons, can regenerate to some extent, but they generally have a limited lifespan and do not replicate indefinitely.

- **Option D: Kidney Cell**:
- Kidney cells, like most somatic cells, have a limited lifespan and can undergo cell death or senescence.

3. **Conclusion**:
- Among the options provided, the germ cell is the only type that is considered immortal because it can give rise to new generations and continues to exist through the process of reproduction.

### Final Answer:
The correct option is **B: Germ Cell**.

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