Figure 1-2. Bacterial cell arrangements.
Two types of fungi are molds and yeasts. See figure 1-3. Molds usually have
branching filaments on which various types of spores are produced. Yeasts are usually
large, round, or oval cells that reproduce by budding. Fungi are usually much larger
Figure 1-3. Types of fungi.
Viruses that infect humans have a variety of shapes and structures ranging from
rod like, to oval, to spherical. See figure 1-4. Compared to bacteria and fungi, viruses
are extremely small. Viruses can be observed only by the use of an electron