Study the following statements regarding mitochondria and select the incorrect ones.
(i) The matrix contains single circular ssDNA molecule, a few RMA molecules , 70s ribosomes
(ii) Mitochondria divide by fission
(iii) Mitochondria bear cisternae
(iv) These are the sites of aerobic respiration

Options

A. i and ii
B. ii and iii
C. I and iii
D. ii and iv

Answer

To solve the question regarding the statements about mitochondria, we will analyze each statement one by one to identify the incorrect ones.

### Step-by-Step Solution:

1. **Statement (i)**: "The matrix contains a single circular ssDNA molecule, a few RNA molecules, 70s ribosomes."
- **Analysis**: Mitochondria indeed contain DNA, but it is a double-stranded circular DNA molecule, not single-stranded (ssDNA). Additionally, they do contain RNA molecules and 70S ribosomes. Therefore, this statement is incorrect due to the mention of "single-stranded" DNA.

2. **Statement (ii)**: "Mitochondria divide by fission."
- **Analysis**: This statement is correct. Mitochondria replicate by a process called fission, which is similar to binary fission seen in prokaryotes.

3. **Statement (iii)**: "Mitochondria bear cisternae."
- **Analysis**: This statement is incorrect. Mitochondria have structures called cristae, which are the infoldings of the inner membrane. Cisternae are associated with the Golgi apparatus, not mitochondria. Therefore, this statement is also incorrect.

4. **Statement (iv)**: "These are the sites of aerobic respiration."
- **Analysis**: This statement is correct. Mitochondria are known as the powerhouse of the cell and are indeed the sites where aerobic respiration occurs, leading to ATP production.

### Conclusion:
The incorrect statements are:
- Statement (i): The matrix contains a single circular ssDNA molecule (it should be double-stranded).
- Statement (iii): Mitochondria bear cisternae (they have cristae instead).

### Final Answer:
The incorrect statements are (i) and (iii).

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