Which of the following graphs shows the relative change in the amount of mitochondrial DNA of a cell undergoing mitosis?

Options

A.
B.
C.
D.

Explanation

To determine which graph shows the relative change in the amount of mitochondrial DNA of a cell undergoing mitosis, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Mitochondrial DNA**: Mitochondrial DNA (mtDNA) is a small circular chromosome found within mitochondria, the organelles responsible for energy production in cells. It is inherited maternally.

2. **Mitochondrial Replication**: Mitochondria have their own replication cycle, which is independent of the cell cycle. This means that the amount of mitochondrial DNA can change independently of the cell's mitotic process.

3. **Cell Cycle Phases**: During the cell cycle, particularly in mitosis, the cell divides into two daughter cells. However, the replication of mitochondrial DNA occurs during the interphase, specifically during the S phase, when DNA replication occurs.

4. **Graph Analysis**: When analyzing the graphs provided, we need to look for a graph that indicates an increase in mitochondrial DNA during the S phase and a relatively stable amount during mitosis.

5. **Identify the Correct Graph**: The correct graph will show an increase in mitochondrial DNA during the interphase (before mitosis) and a plateau or slight decrease during the actual mitotic phase, as the cell is dividing and the mitochondria are being distributed to the daughter cells.

6. **Conclusion**: Based on the analysis, the graph that shows an increase in mitochondrial DNA during interphase and a stable or slightly decreased amount during mitosis is the correct answer. In this case, the correct option is graph A.