BSC 1005 Chapter 17

What is a virus?

• A small, non-cellular
  infectious particle of
  genes in a protein coat
  (and sometimes a membrane)

• a

• aa

• aaa

True or False: Viruses cannot reproduce or metabolize outside of a host cell

• True

• False

What characteristics of life do viruses fulfill? (Select all that apply)

• Has nucleic acids (genetic information)

• Can reproduce

• Undergoes metabolic processes

• Can grow and develop

What is a host range?

• A limited number of host cells a virus can infect

• A size limitation for the hosts a virus can infect

• The amount of viruses a host cell may be infected by

• The limit for the host cell to divide

What happens upon infection by a virus? (Select all that apply)

• The virus creates a viral membrane around the host cell

• The cell manufactures viral proteins using host enzymes, ribosomes, amino acids, etc.

• May cause cell damage and death through lysis or apoptosis

• The host cell dies immediately

True or False: viral envelopes contain molecules from host cell membranes

• True

• False

What is a capsid? (Select all that apply)

• The structure that encloses the viral genome

• A shell made out of protein

• A layer of cillia covering the virus

• The structure that encloses the viral envelope

True or False: The viral envelope surrounds the capsids of many viruses

• True

• False

Bacteriophages are...

• Viruses that infect bacteria

• Bacteria that infect viruses

• Viruses that infect protists

• Bacteria that infect animals

What is the function of the protein tail on a bacteriophage?

• It attaches to the host cell

• It injects its DNA inside the host cell

• It creates a hole in the host cell membrane to embed the virus capsid inside the cell

• It encloses the virus DNA