Chapter 20 Part 1 Test

Question 1

What is a virus? Describe the basic structure of a virus.

Answer 1

Non Living particles are made of proteins, nucleic acids such as dna or rna, and sometimes, lipid membranes.

Question 2

What surrounds all viruses and what is it made of?

Answer 2

capsids; proteins

Question 3

What does a virus have inside that has the instructions for making copies of the virus?

Answer 3

RNA or DNA, never both

Question 4

modified true and false: Viruses only come in THREE shapes, THREE sizes and TWO structures.

Answer 4

False
many, many, many

Question 5

What is on the outside of a virus that acts identifiers?

Answer 5

Proteins

Question 6

What do specific proteins on the outside of a virus do? Why do they do this?

Answer 6

They act as identifiers. they recognize and bind to specific receptors on a cell

Question 7

Most viruses infect a _____ cell.

Answer 7

specific type of

Question 8

What are viruses that only infect bacteria called?

Answer 8

Bacteriophages

Question 9

Why are viruses not living?

Answer 9

They can not reproduce on their own.

Question 10

What are two types of viral infections?

Answer 10

Lytic viral infection and Lysogenic viral infection

Question 11

What does it mean to lyse the cell?

Answer 11

Bursts open the cell membrane

Question 12

Which of the two viruses automatically begins chopping up the host cell’s DNA?

Answer 12

Lytic virus infection

Question 13

Which viral infection never leaves your body? Why?

Answer 13

Lysogenic viral infections;
it incorporates the viral dna into the host dna

Question 14

What is a prophage?

Answer 14

Viral dna that is incorporated into the host dna

Question 15

What are the two ways that viruses cause diseases?

Answer 15

Viruses cause disease by directly destroying host cells or by affecting cellular processes in ways that upset homeostasis.

Question 16

What are two ways that we can prevent viruses? Explain both in detail.

Answer 16

One way you can prevent viruses is by getting a vaccination.
-A vaccination is an injection of a vaccine.
-A vaccine is a weakened virus or a similar but less dangerous pathogen.
-An example of a vaccine is the flu vaccine.
-This vaccine uses a
weakened version of the
influenza virus to train your
body to recognize a protein on the surface of
the virus.

Another way that we can prevent is by practicing personal hygiene.
-Thoroughly wash your hands in order to dislodge the viruses from the skin’s surface
-Keep your fingers off your face and out of your mouth as to not injest the virus

Question 17

What treatments do we have for viruses? Explain what is used and what they do.

Answer 17

The use of an antiviral drug
These are drugs that attack specific viral enzymes that the host cell does not have
They help to speed recovery from a viral infection or stop activation of a viral infection
An example of an antiviral drug is Tamiflu. This works by attacking the flu virus to keep it from multiplying in your body and by reducing the symptoms of the flu.

Question 18

What does a virus have to have to survive? Why?

Answer 18

Viruses are not capable of reproducing themselves, they rely on the hosts cellular mechanisms to do that