Bacteria do not possess :
(a) cell wall
(b) ribosome
(c) mitochondria
(d) plasma membrane

Options

A. cell wall
B. ribosome
C. mitochondria
D. plasma membrane

Explanation

To solve the question "Bacteria do not possess:", we will analyze each option provided:

1. **Understanding Bacteria**: Bacteria are unicellular prokaryotic organisms. This means they do not have a well-defined nucleus or membrane-bound organelles.

2. **Analyzing the Options**:
- **(a) Cell wall**: Bacteria do possess a cell wall, which is primarily made of peptidoglycan. Therefore, this option is incorrect.
- **(b) Ribosome**: Bacteria have ribosomes, specifically 70S ribosomes, which are essential for protein synthesis. Thus, this option is also incorrect.
- **(c) Mitochondria**: Bacteria do not have mitochondria. Mitochondria are membrane-bound organelles found in eukaryotic cells, and since bacteria are prokaryotic, they lack these structures. This option is correct.
- **(d) Plasma membrane**: Bacteria have a plasma membrane, which is a semi-permeable membrane that surrounds the cell. Therefore, this option is incorrect.

3. **Conclusion**: Based on the analysis, the correct answer is option **(c) mitochondria**, as bacteria do not possess this organelle.

### Final Answer:
(c) mitochondria