1. KEY CONCEPT Bacteria and Archaea are both single-celled prokaryotes.

2. Prokaryotes are widespread on Earth.
Prokaryotes can be grouped by their need for oxygen.
obligate anaerobes are poisoned by oxygen
obligate aerobes need oxygen
facultative aerobes can live with or without oxygen

3. Domain Bacteria includes prokaryotes in the kingdom Eubacteria.
one of largest groups on Earth
classified by
1) shape
2) need for oxygen
3) diseases caused

4. Bacteria commonly come in three forms. rod-shaped, called bacilli
Bacteria and archaea are structurally similar but have different molecular characteristics.
Bacteria commonly come in three forms.
rod-shaped, called bacilli
spiral, called spirilla or spirochetes
spherical, called cocci
Lactobacilli: rod-shaped
Enterococci: spherical
Spirochaeta: spiral
Archaea have many shapes.

5. Bacteria and archaea have similar structures. plasmid flagellum pili
cell wall
chromosome
plasma membrance
This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences.

6. Bacteria have molecular differences.
The amount of peptidoglycan within the cell wall can differ between bacteria
GRAM NEGATIVE
GRAM POSITIVE
Archaea have different lipids entirely

7. Domain Archaea includes prokaryotes in the kingdom Archaea.
cell walls chemically different from bacteria
do not contain muramic acid
membrane lipids contain branched carbon chains
differences discovered by studying RNA
known for living in
extreme environments

8. KEY CONCEPT http://www. funsci. com/fun3_en/protists/exhibition
KEY CONCEPT Kingdom Protista is the most diverse of all the kingdoms.

9. Protists can be animal-like, plantlike, or funguslike.
Protists are eukaryotes that are not animals, plants, or fungi.

10. Animal-like protists consume other organisms.
heterotrophs
single-celled

11. Plantlike protists are photosynthetic.
single-celled, colonial, or multicellular
no roots, stems, or leaves

12. Funguslike protists decompose dead organisms.
heterotrophs
can move, whereas fungi cannot

13. Protists are difficult to classify.
Protist classification will likely change.
Some protists are not closely related.
Molecular evidence supports reclassification.