1. Chapter 9: Single-celled Organisms & Viruses

2. Characteristics of living things
All living things…
Have cells (organized)
Grow & develop
Adapt
Respond to the environment
Reproduce
Use energy

3. Levels of Organization
Cells
Tissue
Organ
Organ system
Organism
Levels of Organization

4. Needs of Life All living things need :
Energy – comes from the food and eventually the sun
Materials – such as carbon dioxide, oxygen, & water
Living Space – ex) plants die if weeds invade their living space

5. Unicellular – living thing made up of a single cell
Usually to small to see with the human eye
1 cell carries out all life functions
Ex. bacteria and most protists

6. Chapter 9: Single-celled Organisms & Viruses
Section 2

7. Bacteria the simplest kind of life known on Earth
composed of just one cell without a nucleus
genetic material is in loops within the cell
reproduces using binary fission

8. Anatomy of Bacteria
Capsid

9. Arrangement Paired: diplo- Grape-like clusters: staphylo-
Chains: strepto-

10. may occur singly or in chains
Rod shaped Bacteria
Bacilli (Bacillus)
may occur singly or in chains

11. Spiral Shaped
Spirillia
Occur in single strands

12. Round Shaped Bacteria
Coccus
singly or in pairs,
chains, or clusters

13. Examples of bacterial names
Streptococcus: chains of spheres
Staphylospirillum: Grapelike clusters of spirals
Streptobacillus: Chains of rods

14. Bacteria are grouped by their environmental jobs

15. Producers
transform energy from sunlight into energy that can be used by cells & are a food source for organisms that cannot make their own food.

16. Decomposers
get energy by breaking down materials in decaying organisms & help other organisms reuse materials in decaying matter.

17. Parasites
live in a very close relationship either inside or on the surface of a host & cause harm to their hosts.

18. Archaea are grouped by where they live…

19. Archaea
single-celled organisms that can survive in the largest range of environments.
environments may be in hot, very cold, or contain poisonous materials

20. Methanogens Produce the natural gas methane & die if exposed to oxygen
Live in muddy swamps and marshes, and guts of animals such as cows and termites.

21. Halophiles
live in very salty bodies of water (ex. Dead Sea) & can die if there is too little salt in water
can survive drying and begin dividing again when water returns to a pond

22. Thermophiles thrive in extreme heat or cold
may live in hot springs, near hot vents deep under the sea, or buried deep in the ice

23. Bacteria…
Is it GOOD or BAD?!?

24. Viruses
Section 3
Dead or alive?

25. Viral structure Viruses are not cells. Basic structure: Protein coat
Nucleic acid core (RNA or DNA)
Lipoprotein coat
(second coat – only in enveloped viruses)

26. Virus Categories DNA viruses – stable, do not mutate rapidly
Single-stranded or double-stranded
Smallpox, Hepatitis B
RNA viruses – mutate rapidly, unstable
HIV, Rhinovirus

27. Are viruses alive? Only 1 characteristic of life: reproduction
Can only reproduce inside a host cell!
Process of reproduction = lytic cycle

28. Lytic Cycle Attachment
The virus attaches to the surface of a bacterium.

29. Lytic Cycle
Injection
The virus injects its DNA into the bacterium.

30. Lytic Cycle Production
Using the same machinery used by the host cell for copying its own DNA, the host cell makes copies of the viral DNA.

31. Lytic Cycle
Assembly
New viruses assemble from the parts that have been created.

32. Lytic Cycle
Release
The cell bursts open, releasing 100 or more new viruses.

33. DNA/RNA
Do Now: Draw Me

34. 9.4 Notes
Protists

35. Protists Have a nucleus Do not fit into: They are the “left overs”
Plant
Animal
Fungus
They are the “left overs”
Mostly
single celled
Live in water

36. Protists obtain energy in 3 ways
Eating other organisms (animal-like)
Making their own food (plant-like)
Absorbing their food (fungus-like)

37. Algae Both multi- & unicellular Are plant-like protists Are producers
Types of protists
Algae
Both multi- & unicellular
Are plant-like protists
Are producers

38. Types of movement in protists
Pseudopods (false feet) – tiny extensions of the body
move out and drag the protist along.
Found in Amoeba

39. Types of movement in protists
Flagella – Whip-like tail (or tails)
Act as a rutter and moves back and forth pushing the protist forward and directing it
Ex) Euglena

40. Types of movement in protists
Cilia – tiny hairs
Act as many tiny boat oars and sweep back and forth to move the protist
Ex) Paramecium