covid and viruses

Question 1

virus definition

Answer 1

• A non-cellular, lifeless particle
• Exist as parasites
• Occupy position between living & non-living

Question 2

what can a virus do

Answer 2

Requires a host in order to replicate
Can not make it’s own energy
There are 165 groups of viruses

Question 3

virus description

Answer 3

Viruses are made up of 2 parts:
1. Genetic material which is DNA or RNA
single stranded or double stranded
2. Capsid which is a protective protein coat
and of protein molecules
- accounts for 95% of total virus
-gives virus its particular shape
-Viruses range in size from 20-400 nm (1 nm=10-9m)

Question 4

why are viruses important?

Answer 4

Neutral effect: Population control of other organisms

Negative effect: Responsible for many human diseases. epidemics and pandemics and plays a role in certain cancers (HPV - cervical cancer)

Positive: can be used as a vector to boost immune system (Bubble Boy disease)

Question 5

how does the lytic cycle work in virus reproduction

Answer 5

• Virus attaches to cell
• Injects DNA or RNA into cell
• Host cell makes copies of DNA or RNA
• New virus particles are assembled
• Host cell breaks open and releases new virus particles
• Virus particles able to attack another healthy cell

Question 6

Lysogenic cycle

Answer 6

• Virus injects DNA into cell
• DNA is incorporated into cell’s DNA
• Viral DNA can stay in a dormant state for many years
• As cell goes through mitotic divisions, all following cells contain viral genes
• Something triggers (pH, temperature, stress) the viral DNA to separate and then the lytic cycle starts

Question 7

how does a vaccine work?

Answer 7

a weakened form of a disease antigen (dead or living) is injected into body. the body reacts by creating antibodies to attack the antigen. if the antigen enters the body again, the immune systems antibodies will be able to fight it