Fig. 4.1 presents a diagram of $\textit{S. aureus}$.
Structures such as mitochondria, endoplasmic reticulum (ER), Golgi apparatus, lysosomes and chloroplasts occur only in eukaryotic cells, so they are absent from Fig. 4.1. Using Fig. 4.1, describe other features that show $\textit{S. aureus}$ is a prokaryote.
State the main difference in the composition of the plant cell wall versus the bacterial cell wall.
Bacterial cells act in much the same way as plant cells when placed in solutions with different water potentials. Predict and explain what would happen to bacteria placed in a solution whose water potential is more negative than that of their cell contents.
Some strains of $S.\,aureus$ have become resistant to one or more of the antibiotics used to treat infections. The mechanisms of antibiotic resistance involve proteins, for example: enzymes that break down antibiotics; membrane proteins that inactivate antibiotics; membrane proteins that pump out antibiotics. Explain why antibiotic resistance results from mutation.