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Flashcards in Chapter 17 Deck (17)
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1
Q

Virus

A

An infectious particle consisting of little more than genes packages in a protein coat but can not reproduce or carry out metabolism outside of a host.

Can have single or double stranded DNA

2
Q

Capsid

A

Protein she’ll enclosing the viral genome

3
Q

Viral envelope

A

A membrane, derived from membranes of the shot cell, that cloak the capsid which in turn enclosed a viral genome

4
Q

Bacteriophages

A

Virus that infects bacteria

5
Q

Host range

A

Range of species a virus can use as a host

6
Q

Lytic cycle

Virulent phage

A

A phase replicative cycle that culminates in death of the host cell by lysing a bacterium and releasing phases produced by the cell

Phage produced by lytic cycle

7
Q

Lysogenic cycle

Template phages

A

Allows replication of the phage genome without destroying the host. Environmental signal triggers cell to induce lytic cycle

Phages capable of both modes of replicating within a bacterium

8
Q

Prophage

A

A phage genome that has been inserted into a specific site on a bacterial chromosome

9
Q

3 types of single stranded RNA genomes found in viruses

A
  1. Viral genome directly serves as mRNA (positive sense)
  2. Rna gene serves instead as a template for mRNA synthesis (- sense)
  3. Retrovirus: an RNA virus that replicates by transmitting it’s RNA into DNA anD then inserting the DNA into a cellular chromosome (reverse transcriptase)
10
Q

Provirus

A

A viral genome that is permanently inserted into a host genome

11
Q

Epidemic vs, pandemic

A

Widespread outbreak

Global epidemic

12
Q

Do virus’s have mutations?

A

RNA viruses have high rates of mutations because viral rna polymerase does not proofread.

13
Q

Horizontal and vertical transmission

A

Horizontal- infect by external source of virus

Vertical- a plant inherited a viral infection from parent

14
Q

How do plant viruses spread?

A

Through plasmodesmata

15
Q

Prions

A

An infectious agent that is a misfolded version of a protein. Increase in number by converting correctly folded versions to more prions.

  • act very slowly(incubate 10 years)
  • virtually indestructible
  • in brain causes neuronal damage and death.
16
Q

Transporons

A

Move from one location to another withi;a cells genome

17
Q

Genetic shift

A

Animal infected with more than one strain may result in genetic recombination. (New strains)