The correct answer is option 4 - Mitochondria. Bacterial cells are prokaryotic cells, which means they lack many of the organelles found in eukaryotic cells. One of the major organelles absent in bacterial cells is the mitochondria. Mitochondria are responsible for producing energy in eukaryotic cells through the process of cellular respiration. Since bacterial cells do not have mitochondria, they utilize different mechanisms to generate energy, such as glycolysis or fermentation.

On the other hand, let`s review the other options:

Option 1 - Cell wall: Bacterial cells do have a cell wall, which provides structural support and protection to the cell. The composition and structure of the cell wall may vary among different types of bacteria.

Option 2 - Plasma membrane: Bacterial cells do have a plasma membrane, also known as the cell membrane. This membrane surrounds the cytoplasm of the cell and regulates the movement of substances in and out of the cell.

Option 3 - Ribosome: Bacterial cells do have ribosomes. Ribosomes are responsible for protein synthesis and can be found in both prokaryotic and eukaryotic cells.

Therefore, the correct answer for the option that bacterial cells do not have