Viruses

Question 1

lytic cycle

Answer 1

one way a virus can reproduce that kills the host cell right away; this process is when viral genomes and viral proteins are made into new viruses that will be released from the cell once it lyses

Question 2

transposons

Answer 2

segments of dna that can jump from one location to another in the cell’s genome; this is one possibility that scientists think could have been the original source of viral genomes

Question 3

restriction enzymes

Answer 3

these recognize and cut up foreign DNA in bacteria; it is the defense mechanism of bacteria against viruses

Question 4

retrovirus

Answer 4

rna viruses that do an rna –> dna information flow; use reverse transcriptase; an example of these is HIV

Question 5

virus

Answer 5

infectious particle consisting of genes and a protein coat

Question 6

capsomere

Answer 6

protein subunits of the capsid

Question 7

prions

Answer 7

infectious proteins that typically attack the brain tissue; causes normal brain proteins to turn into the misfolded form and thus causes brain damage

Question 8

vaccines

Answer 8

harmless variants of a pathogen that can stimulate the immune system to mount defenses against the actual pathogen

Question 9

prophage

Answer 9

viral dna that incorporates itself into the bacterial genome

Question 10

virulent phages

Answer 10

phages that replicate only by the lytic cylce

Question 11

viral envelope

Answer 11

a component of viruses that only some viruses have; these are typically derived from the plasma membrane of the host cell

Question 12

horizontal transmission

Answer 12

one way that plant viruses can spread is by the plant being infected from an external source such as insects or farm equipment

Question 13

HIV

Answer 13

the virus that causes AIDS; this is a retrovirus

Question 14

bacteriophage

Answer 14

a virus that infects a bacteria

Question 15

Wendell Stanley

Answer 15

crystallized the TMV

Question 16

lysogenic cycle

Answer 16

one way a virus can reproduce that does not kill the host cell right away; the virus can lay dormant in the genome of the host cell and just get replicated every time the bacteria divides

Question 17

obligate intracellular parasite

Answer 17

the term that describes viruses since they can only replicate and function in a host cell

Question 18

capsid

Answer 18

the name for the protein coat in a virus

Question 19

plasmids

Answer 19

small, circular dna molecules that are separate from chromosomes, can replicate independently of the rest of the cell, and are occasionally transferred between cells; these are another possibility for the original source of viral genomes

Question 20

reverse transcriptase

Answer 20

the enzyme that retroviruses use to go from rna back to dna

Question 21

temperate phages

Answer 21

virues that use both lytic and lysogenic reproductive cycles

Question 22

vertical transmission

Answer 22

when plant viruses spread the infection from parent to offspring; this can be done asexually or sexually using seeds

Question 23

antibiotics

Answer 23

these can kill bacteria but are powerless against viruses

Question 24

host range

Answer 24

the range of cells that viruses are able to infect

Question 25

AIDS

Answer 25

the disease caused by the HIV virus

Question 26

provirus

Answer 26

viral genome that is permanently inserted into a host cell’s genome

Question 27

mobile genetic elements

Answer 27

plasmids and transposons are called this because they are able to move within the genome

Question 28

viroid

Answer 28

one type of infectious agent that is smaller than viruses; naked rna; these demonstrate that it only takes a single molecule to spread disease; these infect plants

Question 29

antiviral drugs

Answer 29

drugs that are given when a person gets infected with a virus; they interfere with viral nucleic acid synthesis

Question 30

Adolf Mayer

Answer 30

he gets credit for discovering viruses; researched tobacco mosaic virus