Virus (U3)

Question 1

What are parts of a virus?

Answer 1

Nucleic acid, capsid and lipid membrane

Question 2

What is nucleic acid?

Answer 2

RNA/DNA

Question 3

Capsid definition?

Answer 3

Protein coat that surrounds DNA/RNA of a virus

Question 4

Lipid membrane definition?

Answer 4

Membrane around the capsid in many kinds of viruses
- Helps virus enter cells
- ‘Enveloped viruses’, without membrane= naked virus
- Make of lipids, proteins and glycoproteins

Question 5

What are traits of RNA?

Answer 5

Mutates rapidly, unstable
- Can produces hundreds/thousands of times, mutating easily
- Evolves faster than any other living organism
- Ex. HIV, rabies, influenza

Question 6

What are traits of DNA?

Answer 6

Don’t mutate, stable
- Typically cause latent infection
- Viral latency
- Ex. warts, chickenpox, mononucleosis

Question 7

What is viral latency?

Answer 7

Ability of a pathogenic virus to lie dormant (latent) within a cell

Question 8

What are virus shape? (not on the test)

Answer 8

Helical, polyhedral, binal polyhedral capsid

Question 9

What is helical? (not on test)

Answer 9

Rod like with capisd proteins winding around the core in a spiral

Question 10

What is polyhedral? (not on test)

Answer 10

Has many sides, must have 20 sides with 12 corners

Question 11

What is binal polyhedral capsid? (not on test)

Answer 11

Attached to helical tail

Question 12

What are the two ways that viruses reproduce?

Answer 12

Lytic and lysogenic

Question 13

What do bacteriophages/viruses do once they enter lytic cycle?

Answer 13

Once inside a host, destroys cell during reproduction

Question 14

When do bacteriophages/viruses enter lysogenic cycle?

Answer 14

After lytic, parasitic type of partnership with the cell

Question 15

What do bacteriophages and viruses attack?

Answer 15

Bacteriophages= bacteria (prokaryotic)
Viruses= attack eukaryotic cells

• Both invade cells and use host cell’s machinery to synthesize more of their own macromolecules

Question 16

What is the lytic cycle?

Answer 16

Virus enters cell, replicates itself hundreds of times then bursts out of the cell, destroying it
- Virus reproduces itself using host’s machinery

Question 17

What is the lysogenic cycle?

Answer 17

Virus DNA integrates with host DNA and host’s cell helps create more virus DNA
- Environmental change may cause virus to enter lytic
- Virus reproduces by first injecting its genetic material

Question 18

How do viruses enter a cell?

Answer 18

Punching a hold in the cell wall and injecting its DNA

Question 19

How and why do viruses mutate?

Answer 19

Viruses mutate when they copy genetic material
- Copy something wrong
- Mistake proves useful
- More powerful virus (infection)
- Don’t mutate often (exceptions= HIV, influenza)