Virus and Bacteria Test Review

1. Define bacteria. Unicellular, autotrophs or heterotrophs (parasitic), can be

pathogens, can be good or bad for the body

2. Be able to determine what a virus is. Viruses are non-living, unicellular

parasites. They must take over a cell in order to continue their cycle.

3. As an endospore, bacterium are protected by a very tough outer shell.

4. What is a retrovirus? A virus that contains RNA that can be transcribed into

DNA

5. The first vaccine was developed for? smallpox

6. What is the lytic cycle? Host cell bursts, releasing new viruses into the host's

system, each of which infects another cell

7. What is the lysogenic cycle?

a. virus combines its DNA into the host cell's DNA.

b. Forms a provirus.

c. Virus lays “dormant” as host cell reproduces.

d. When triggered it can activate the provirus

i. or it can remain a permanent gene and not be activated.

e. When ready to release the provirus it then enters a lytic cycle style

attack on the immune system and body.

8. What is a viroid? Plant virus

9. What is a capsid? Virus protein coat

10.What is a T Cell?

a. HELPERS - tell the immune system to build a clone army of disease

fighters

b. KILLERS - kill the virus/pathogen

i. tanks (Tk)

11.What is a B Cell? - bombers (B-cells) make antibodies

12.What is a Macrophage? Eaters – eat the bad stuff

13.What is a prion and what is it made of? Disease causing particle made of

proteins

14.What is the difference between primary immune response and secondary

immune response? The secondary immune response is faster because of the

memory cells that were created in the primary response.

15.Be able to identify the shapes of bacteria.

16.What is the difference between Archaebacteria and Eubacteria?

a. Archae – old and can live in extreme environments. Can convert

inorganic molecules into fuel.

b. Eubacteria – are the common form of bacteria. Are either

heterotrophs or autotrophs

17.Why is bacteria important in plants? Bacteria is used in plants, to convert

atmospheric nitrogen into a usable form for animals through a process called

nitrogen fixation.

18.How do chemioautotrophs gain their nutrients? They get their nutrients from

inorganic substances

19.What is conjugation in bacteria?

a. Sexually reproduce

b. One bacterium transfers part of its chromosome (plasmid) across a

pilus

c. Offspring not genetically identical to parent

20.What is the process by which bacteria can create fertilizing compounds for

plants from the air called? Nitrogen fixation

21.What is binary fission?

a. Asexual reproduction

b. one bacteria splits into two bacteria, and then grows exponentially

c. Takes less than 20 minutes under ideal conditions

22.In what products are bacteria used to create them? Yogurt, cheese, Vinegar,

wine

23.What causes a virus to move from the lysogenic cycle to the lytic cycle?

a. Once a provirus is triggered the virus will enter the lytic stage and

symptoms will develop

24.Why is a virus considered non-living?

a. do not have their own cells

b. Need living cells to help them reproduce

c. They are parasites

25.What is the difference between the cell wall in a bacteria and a cell wall in a

plant?

a. Plant has cellulose in their cell wall

b. Bacteria has peptidoglycan in their cell wall

26.What is the purpose of a ligand in a virus? A ligand is a chemical messenger

that tells a receptor what it is. This causes a change in the cell. Without it, a

cell could possibly not know if a virus was approaching it. It basically

deceives the host cell.

27.What is a plasmid? Small portion of DNA used in conjugation of bacteria

28.What is in a vaccine that helps the immune system?

a. vaccines can contain the “spikes” of a virus for practice for the

immune system

b. By showing your body the antigen, your body can run through a

primary response

c. The whole point - to produce memory cells, so if it happens again it

can fight off the virus quicker

29.What type of bacteria might be found in the digestive systems of herbivores?

Methanogens

30.How does a memory cell help the body fight off recurring diseases? memory

cell is a unique property of the immune system because it can “store”

information about a stimulus and can mount an effective response when the

stimulus is encountered again. This response – a secondary immune

response – is quicker and stronger than the primary response, due to the

creation of the memory cell in the primary immune response.

31.What is the difference between gram-positive and gram-negative bacteria?

Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall,

which itself is surrounded by an outer membrane. Gram-positive bacteria

lack an outer membrane but are surrounded by layers of peptidoglycan

many times thicker than is found in the Gram-negatives

32.What is the purpose of the human immune system? Protect the body from

foreign invaders and prevent disease.

33.Explain the lytic cycle of a virus. When a virus has infected a cell, it

replicates new virus particles, once matured the virus bursts through the cell

membrane. This releases the new virus complexes, so they can infect more

cells.

34.Be able to label and describe the different parts of bacteria in the diagram

below.

35. Be able to label the three different parts of the virus

36.Be able to describe the process of conjugation in bacterial cells. The process

by which a bacteria transfers its genetic material to another cell through

direct contact.