<p><strong>Fig. 1.2.</strong> (<strong>D</strong>) The bacterium <em>Staphylococcus aureus</em> is invisible to the humans without the aid of a powerful scanning electron microscope.</p>

Fig. 1.2. (D) The bacterium Staphylococcus aureus is invisible to the humans without the aid of a powerful scanning electron microscope.

Image courtesy of Janice Carr, Centers for Disease Control and Prevention (CDC), adapted from Wikimedia Commons