A2.3 Viruses

Question 1

Virus Components

Answer 1

Capsid (protein protective barrier surrounding RNA/DNA), do not contain organelles

Question 2

Bacteriophages

Answer 2

Contain a capsid head (double- stranded linear DNA), tail, non-enveloped -> hosted by e.coli

Question 3

Variety of genetic info in viruses

Answer 3

Can either be DNA/RNA, single-stranded/double-stranded, linear or looped

Question 4

Enveloped/non-enveloped virus

Answer 4

whether or not a lipid membrane is present

Question 5

Covid

Answer 5

Contain a complex capsid (single-stranded linear DNA), enveloped structure

Question 6

Retrovirus

Answer 6

HIV -> virus that reproduces by converting its RNA into DNA

Question 7

Lytic cycle

Answer 7

Virus attaches & inserted its genetic info. into host, replicates itself using the hosts organelles, and then bursts out (killing the cells) & releasing new viruses.

Question 8

Lysogenic cycle

Answer 8

Virus attaches & inserted its genetic info. into host, replicates itself using the hosts organelles & integrating with the cell’s genome. Infected cell divides, producing more viruses. Results in long-term dormant infection.

Question 9

Progressive hypothesis

Answer 9

Viruses arose by taking and modifying host cell components

Question 10

Regressive hypothesis

Answer 10

Viruses arose by loss of cellular components.