Unit C

Question 1

explain why viruses are considered non-living

Answer 1

viruses are nonliving because they cannot reproduce on their own, do not carry out metabolism, and lack cellular structure. They need a host to replicate.

Question 2

compare and contrast the lyric and lysogenic cycles

Answer 2

lyric cycle: viruses immediately replicate, destroying the host cell. Is fast and active.
lysogenic cycle: viral, DNA integrates into host DNA and can stay inactive for a long time. Is slow and dormant.
similarities: both involve viral, replication, and host cells

Question 3

briefly describe transmission routes for viruses

Answer 3

airborne - flu, COVID-19
Direct contact - HIV
contaminated food/water - norovirus
vector-borne - zika via mosquitoes

Question 4

describe 3 ways to reduce the spread of viral diseases

Answer 4

1. vaccination
2. hand washing and good hygiene
3. avoid contact with infected individuals or surfaces

Question 5

List and provide an example of each of the three lines of defense

Answer 5

first line: physical/chemical barriers (skin, tears)
Second line: non-specific defenses (inflammation)
third line: specific immune responses (antibodies, T-cells)