Ch 13 Viruses, Viroids and Prions

Question 1

List the differences between bacteriophage and animal viral multiplication.
Draw the stage process.

Answer 1

BACTERIOPHAGES ANIMAL VIRUSES
Tail fibers attach to cell wall Plasma membrane attach.
Viral DNA injected into hose Capsid endocytosis
Uncoating not required Enzymatic uncoating
Biosynthesis in cytoplasm In nucleus or cytoplasm
Lysogeny Latency
Host is lysed Budding and host ruptures

Attachment, Entry, Uncoating, Chronic infection, Biosynthesis, Release

Question 2

How do RNA viruses replicate?

Answer 2

Viruses take over host cell through lysogenic or lytic cycle.

Question 3

Define oncogenes

Answer 3

A gene that can transform a cell into a tumor cell.

Question 4

Which viruses can cause cancer?

Answer 4

Epstein-Barr virus, human papilloma virus, hepatitis B virus, and human herpes virus

Question 5

Why is the Tobacco Mosaic Disease important and what is it?

Answer 5

First virus to be discovered.

RNA virus that infects tobacco plants, by causing a mosaic on the leaves. Does not cause harm to humans.

Question 6

What is the name of a virus that cannot be filtered?

Answer 6

Yellow fever

Question 7

What is phage therapy?

Answer 7

Using viruses to threat diseases

Question 8

Are viruses alive?

Answer 8

Viruses cannot replicate on their own but can do so in truly living cells and can also affect the behavior of their hosts profoundly.
Use nucleic acids ->life
Inert outside of living cells
Take over metabolism of cells

Question 9

Characteristics of viruses?

Answer 9

Nucleic aids

Multiply inside living cells

Question 10

What is a viron?

Answer 10

Infective form of a virus outside a host cell, with a core of RNA or DNA, with a capsid.

Question 11

What is a capsid?

Answer 11

A capsid is the protein shell of a virus.

Question 12

What is a icosahedron? What is an example?

Answer 12

20 triangular faces with 12 corners

Polio virus

Question 13

What are the two structures of a bacteriophage?

Answer 13

Capsid + helical tail

Question 14

What are the virus suffixes in taxonomy for, Order, Family, and genus?

Answer 14

Order: -ales
Family: virdae
Species: -virus

Question 15

Why are some people allergic to vaccines?

Answer 15

Because they are grown in chicken eggs.

Question 16

What are HeLa cells? What are they used for?

Answer 16

Human epithelial cells.

HeLa cells to develop the polio vaccine, cancer, HIV/AIDS and cells in general, and are still widely used today to grow viruses and to test anti-tumor medicines.

Question 17

What are the components of a T-even bacteriophage?

Answer 17

Capsid -head
Sheath
Baseplate
Pin
Tail fiber

Question 18

Which are better for growing vaccines, eggs or cultures?

Answer 18

Cultures

Question 19

What happens at the end of the lytic cycle?

Answer 19

The host dies

Question 20

What happens at the end of the lysogenic cycle?

Answer 20

The phage remains latent - inactive

Question 21

What is phage conversion?

Answer 21

The host cell develops new properties

Question 22

Where do DNA viruses replicate their DNA?

Answer 22

Their replicate their DNA in the nucleus of the host’s cell.

Question 23

Where do RNA viruses replicate their RNA?

Answer 23

Their replicate their RNA in the cytoplasm of the host’s cell.

Question 24

Which RNA virus can cause cancer?

Answer 24

Retroviridae

Question 25

What is an example of a latent virus?

Answer 25

Chickenpox (Varicellovirus) becomes shingles.