Viruses/Bacteria Worksheet
1. What is this structure?
A bacterium.
2. Identify parts A-F
A. Capsule
B. Cell wall
C. Circular DNA plasmid
D. Pili
E. Circular DNA
F. Flagellum
3. Name the two kingdoms of bacteria. List one way these groups differ
from each other.
One of the differences between ‘bacteria’ and ‘viruses’ is that a virus
can’t live on its own, it needs a host in order to survive.
4. Describe two roles bacteria have in the environment.
Some bacteria help to prevent other bacteria (that cause diseases) from
entering our body or certain tissues. Also, some bacteria help to
preserve food.
5. What are three foods that have been made using bacteria?
Yoghurt, bread and cheese.
6. Following a flood, people are often advised to boil their drinking water.
Explain why this is necessary.
Because of the flood, rainwater and water from seas, rivers, canals, etc.
mixes with drinking water. Drinking water is cleaned so that it doesn’t
contain harmful bacteria anymore. But when drinking water is mixed up
with water that isn’t cleaned, it can contain those harmful bacteria. The
advice to boil drinking water is necessary because bacteria can’t multiply
at high temperatures.
7. Describe two ways of killing bacteria.
You can kill bacteria by using antibiotics and disinfectants (f.e. bleach)
and by cooking/boiling them.
8. How are bacteria classified?
Bacteria are classified as a domain.
9. What are the three main shapes of bacteria?
Spirilla, bacilli and cocci.
10. What is this structure to your right?
It’s a bacteriophage.
11. What type of organism does this virus infect?
This kind of virus only infects bacteria.
12. Label parts A-D
A. Head/protein coat
B. Sheath
C. DNA
D. Tail fibers
Virus life cycle A–G
13. Which letter indicates the host cell being lysed (destroyed)?
F
14. Which letter above represents the stage at which a host cell begins
producing new bacteriophages?
D
15. Which letter indicates the stage at which the bacteriophage injects its
DNA into the host cell?
G
16. Looking at the above diagram which viral life cycle (lysogenic or lytic)
is actively using and then lysing (destroying) body cells to make more
viruses?
F