1. Bacteria, Viruses, and Cells

2. Bacteria, Viruses, and Cells
We are going to discuss the similarities and differences in Bacteria, Viruses, and Cells
By the end of the lesson you should be able to explain:
Whether or not they are alive and how we can tell
How they Reproduce
What type of genetic material they contain
And give some examples of each

3. Bacteria
Cells
Viruses

4. Basics Bacteria Cells Viruses Eukaryotes or Prokaryotes Have
organelles
Many different
types and they
can be
specialized
Segments of Nucleic Acids contained in a protein coat (capsid)
Some have an envelope around the capsid
Not prokaryote or eukaryote
Much Smaller than Bacteria and Cells
Variety of shapes
Antibiotics do not kill them
Only harmful
Prokaryotes
Can be beneficial or harmful
No internal compartments or membrane systems
They are single celled
Three basic shapes
Bacillus –rod
Coccus – round
Spirillum – spiral
Antibiotics do kill them

5. Are they alive and How do we know?
Bacteria
Cells
Viruses
Bacteria Are ALIVE
They can metabolize food
They do contain Ribsomes to make proteins
They can reproduce without a host cell
Cells are ALIVE
They can
metabolize
food
They do contain
ribosomes to
make proteins
reproduce
without a host
cell
Interact with
their
surroundings
Viruses are NOT ALIVE
They cannot metabolize food
They have no structures to make proteins (ribosomes)
They cannot reproduce without a host cell

6. How do they Reproduce? Bacteria Cells Viruses
Bacteria reproduce by a process called Binary Fission
Cells reproduce
Mitosis – for most cells
Meiosis - for gamete cells
Viruses have 2 possible ways of reproducing
Lytic Cycle
Lysogenic Cycle

7. What Type of Genetic Material Do They Have?
Bacteria
Cells
Viruses
DNA and RNA
DNA is found in the cytoplasm because Bacteria have no nucleus
Round DNA
DNA and RNA
Found in the nucleus
Linear DNA
DNA OR RNA, but not both

8. How are they transmitted?
Bacteria
Viruses
Bacteria and viruses are transmitted in much the same way
Inhalation
Direct Contact
Contact with Body Fluids (Blood, Saliva, semen)
Contaminated food or water
Bite of an infected animal or insect

9. Examples Bacteria Cells Viruses Cholera Dental Cavities Strep Throat
Tetanus
Used in making food and beverages
Mycorrhizae
Muscle cells
Nerve Cells
Guard Cells
AIDS
Common Cold
Flu
Rabies
Hepatitis
Smallpox

10. TAKS Question
Which of the following is found in both cells and viruses?
A Silica
B Genetic material
C Digestive cavity
D Flagella

11. TAKS Question Viruses differ from bacteria in that all viruses —
F cause insect-borne diseases
G can be destroyed by antibiotics
H have rigid cell walls
J must be reproduced in living cells

12. TAKS Question What process is shown to the left? A Cellular ingestion
B Pseudopod formation
C Cell wall digestion
D Binary fission

13. TAKS Question
Which of the following cannot metabolize nutrients?

14. TAKS Question
What is the most common threat to a host organism posed by an invading virus?
A Production of viral fluids in the bloodstream
B Fermentation of acids in the digestive system
C Destruction of cells by viral reproduction
D Stimulation of muscle tone in the heart

15. TAKS Question Which of these does a virus need in order to multiply?
A Chloroplasts from a host cell
B A host cell to provide oxygen for the virus
C New ADP from a host cell
D A host cell to replicate the virus’s DNA