The correct answer is 4 - zero. Bacterial cells are prokaryotic cells, which means they do not have a nucleus or membrane-bound organelles like mitochondria. Mitochondria are found in eukaryotic cells, which include plants, animals, and fungi. Mitochondria are responsible for producing energy in the form of ATP through cellular respiration. They have a double membrane and their own DNA, which suggests that they originated from an ancient endosymbiotic event where a bacterial cell was engulfed by a eukaryotic cell. Therefore, bacterial cells do not have mitochondria and rely on other processes to generate energy, such as glycolysis and fermentation.