1. Prokaryotes and Protists

2. 16.7 Prokaryotes have inhabited Earth for billions of years
Prokaryotes are the oldest life-forms
They remain the most numerous and widespread organisms on Earth today
Figure 16.7

3. 16.8 Archaea and bacteria are the two main branches of prokaryotic evolution
Prokaryotes are cells that lack nuclei and other membrane-enclosed organelles

4. Prokaryotes are classified into two domains, based on nucleotide sequences and other features
Bacteria and Archaea
Table 16.8

5. 16.9 Prokaryotes come in a variety of shapes
Spheres (cocci) are the most common
Rods (bacilli)
Curves or spirals
Figure 16.9A-C

6. 16.10 Prokaryotes obtain nourishment in a variety of ways
These E. Coli colonies are growing with only glucose as an organic nutrient
Figure 16.10

7. Autotrophs obtain carbon from CO2 and are of two types
Photoautotrophs and chemoautotrophs
Heterotrophs obtain carbon from organic compounds
Photo- heterotrophs and chemo- heterotrophs
Table 16.10

8. The first cells were most likely chemoautotrophs
They may have gotten their energy from sulfur and iron compounds

9. 16.11 Archaea thrive in extreme environments—and in the ocean
Archaea live in
anaerobic swamps
salt lakes
acidic hot springs
deep-sea hydrothermal vents
animal digestive systems
Figure 16.11A, B

10. Rotating flagella aid in locomotion
Diverse structural features help prokaryotes thrive almost everywhere
Rotating flagella aid in locomotion
Flagellum
Plasma membrane
Cell wall
Rotary movements of each flagellum
Figure 16.12A

11. Pili help cells cling to surfaces
Figure 16.12B

12. Endospores allow certain bacteria to survive environmental extremes in a resting stage
Figure 16.12C

13. Many prokaryotes grow in linear filaments
Figure 16.12D