Cell Diversity and Viruses

Question 1

T or F: Viruses are cells.

Answer 1

False

Question 2

What are viruses?

Answer 2

Macromolecular packages that can function and reproduce only within living cells

Question 3

What is a virion?

Answer 3

A virus outside of a host cell

Question 4

Are virions animate or inanimate particles?

Answer 4

Virions exist as inanimate particles

Question 5

What two things make up virions?

Answer 5

• A small amount of DNA or RNA
• A capsid

Question 6

What is a capsid in a virion?

Answer 6

A protein capsule that packages genetic material

Question 7

What are the 5 properties of cells that are shared with viruses?

Answer 7

• Complex and organized
• Controlled by a genetic program
• Able to carry out chemical reactions (sometimes)
• Able to reproduce (sometimes)
• Capable of evolving

Question 8

What do viruses need to reproduce?

Answer 8

A host cell

Question 9

When are viruses able to carry out chemical reactions?

Answer 9

Only when enzymes are present on the exterior of the virus

Question 10

What is the Baltimore Classification System?

Answer 10

A popular system for classifying viruses

Question 11

How does the Baltimore Classification System categorize viruses?

Answer 11

Based on their type of genome and method of replication

Question 12

What is an example of a virus classified under the hepadnavirus family?

Answer 12

Hepatitis B

Question 13

What is an example of a virus classified under the filovirus family?

Answer 13

Ebola virus

Question 14

How does the filovirus family encode their genome?

Answer 14

In the form of single-stranded negative-sense RNA

Question 15

What can viruses in the adenovirus family cause?

Answer 15

Respiratory illness or conjunctivitis

Question 16

How do retroviruses infect host cells?

Answer 16

Insert a copy of their genome into the DNA of a host cell

Question 17

Are retroviruses an RNA or DNA type virus?

Answer 17

RNA

Question 18

What is an example of a retrovirus?

Answer 18

HIV

Question 19

What type of cells do bacteriophages infect?

Answer 19

Infects and replicates within prokaryotes

Question 20

What is CRISPR-Cas?

Answer 20

An immune-like system bacteria have evolved to possess as a way to battle continuous attacks from bacteriophages

Question 21

How does CRISPR-Cas work?

Answer 21

Recognizes and remembers the attack from a virus, so it knows which enzymes to release to effectively and efficiently fight back

Question 22

What is the main factor that determines what cell type a virus can infect?

Answer 22

The expression of specific surface proteins

Question 23

What is the difference between narrow and wide host ranges?

Answer 23

• Narrow host range: viruses that have specific preferences in terms of which cells they infect
• Wide host range: viruses that infect a wide range of different cells

Question 24

Do human cold and influenza viruses have narrow or wide host ranges?

Answer 24

Narrow

Question 25

Does rabies have a narrow or wide host range?

Answer 25

Wide

Question 26

What does a virus do once inside a host cell?

Answer 26

Hijacks cellular machinery to synthesize nucleic acids and proteins

Question 27

What are the two main types of viral infections?

Answer 27

Lytic and non-lytic

Question 28

What is the difference between lytic and non-lytic viruses?

Answer 28

- Lytic: produces virus particles that rupture/kill host cell - Non-lytic: host cell can survive, but often with impaired function

Question 29

What is a provirus?

Answer 29

Viral DNA inserted into the host genome

Question 30

Are influenza and rabies lytic or non-lytic viruses?

Answer 30

Lytic

Question 31

Are HIV and chicken pox lytic or non-lytic viruses

Answer 31

Non-lytic

Question 32

What type of genome does the rabies virus have?

Answer 32

A single stranded RNA genome

Question 33

How do RNA vaccines work?

Answer 33

Trick the body's cells into producing an antigen from an RNA template, so when the actual virus attacks the body defends itself more effectively

Question 34

What is an antigen?

Answer 34

A substance that causes the body to make an immune response against it

Question 35

What is one strategy to make RNA vaccines more effective?

Answer 35

Incorporate the instructions for assembling a replicate within them

Question 36

What will the replicas that result from self-amplifying RNA vaccine do?

Answer 36

Make copies of the RNA template for producing antigens