1. To spark interest in cosmology, show recent photos taken by the Hubble telescope, some of which are in color and show galaxies being "born."

2. Next, show a picture of the Milky Way galaxy and discuss the uncertainty concerning the existence of life outside Earth.

1. Discuss generally the fact that experiments have been designed to try and recreate the conditions surrounding the formation of life from nonliving matter.

2. Figure 29.1 may provide an easy illustration of one such experiment.

1. Emphasize the genetic and evolutionary themes in this text by pointing out that both a genome (as we know it) and, therefore, opportunities for natural selection, were absent in early life forms.

2. Be certain to include discussion of RNA as the probable first functional nucleic acid, and show Figure 29.2.

1. Focus on Concepts 29.1 and discuss the six major modes of metabolism which have evolved to date (see Figure 29.3).

2. Show pictures of representative organisms, such as green sulfur bacteria (Figure 29.5), purple sulfur bacteria (Figure 29.6), cyanobacteria (Figures 29.7 and 29.8) and discuss heterotrophy, photosynthesis, and aerobic respiration as early metabolic processes.

1. Focus on defining the Monera, and include mention of Sidebar 29.1 on the Archaebacteria.

2. A source of confusion is the belief that procaryotes are small in size; in reality, species range from 10—300 micrometers in diameter or length (Figure 29.9).

3. Show Figure 29.10 and discuss the specific content of bacterial cell walls and contrast them with plant cell walls.

1. Show Figures 29.11, 29.12, and 29.13 in discussing varied morphologies in bacteria.

2. Consider a demonstration as follows: In front of the class, streak LB plates with swabs from your surroundings (e.g. clothing, hair, your forehead, a book, a shoe) and allow these to grow until colony morphology is apparent. Then, discuss how colony morphology and cell morphology are related. Remember that fungi will likely also be present on the plates.

3. Discuss mycobacteria (Figure 29.15) in relation to tuberculosis and leprosy and show pictures of human limbs affected by leprosy, and sanitariums where, as recently as the 1960s, people with TB were sent.

4. Discuss mycoplasmas and the fact that they lack cell walls and grow into irregular forms (Figure 29.16).

1. Show Table 29.1 and discuss the major procaryotic groups.

2. Discuss the Gram stain (Figures 29.19 and 29.20) and how it currently plays an active role in medicinal bacteriology (e.g. it is used to determine bacterial types from throat cultures).

3. Distinguish obligate and facultative organisms (Figures 29.17 and 29.18).

1. Emphasize the importance of bacteria in cycling of materials in ecosystems.

2. Figures 29.21 and 29.22 show the role of bacteria in the nitrogen and sulfur cycles.

1. Show pictures from a medical text illustrating the manifestations of infectious diseases caused by bacteria.

2. Consider obtaining data from a local or regional health center about the epidemiology of human disease in your area or on your campus; obtain similar data on domestic animals from agricultural centers.

3. Show photos of industrial pasteurization plants for milk or wine.

4. Show a picture of Louis Pasteur and discuss his many contributions in the study of contagious disease.

1. Show Figures 29.24 and 29.25 and discuss how infectious agents are transmitted from reservoirs of infection.

1. Use chlamydia, a common STD, as an example of an intracellular pathogen (Figure 29.26).

1. Again, show pictures of industrial plants and equipment where bacteria are used in the processing of materials (Figure 29.27).

1. Show color pictures of actual viruses or of computer models that have been made for many of them (e.g. Ebola virus, tobacco mosaic virus).

2. Discuss the structures of viruses and show Figures 29.28—29.32.

1. Show Figure 29.33 and discuss virus replication.