Viruses

Question 1

What do simple viruses have (structure of simple viruses)?

Answer 1

Protein coat that surrounds genetic material (DNA/RNA)

Question 2

What are the 4 types of viruses?

Answer 2

Helical viruses (e.g. Tobacco Mosaic Virus
Polyhedral viruses (e.g. adenovirus)
Spherical viruses (e.g. Coronavirus)
Complex viruses (e.g. bacteriophages)

Question 3

How do viruses replicate? (example: infection of bacterium by bacteriphage)

Answer 3

1. The bacteriophage attaches to the host cell (bacterium)
2. Injects genetic material in the host cell
3. The bacterium is infected, and starts replicating the virus
4. The host cell bursts, and the new viruses leave the cell
5. The viruses attach to new host cells, and the cycle repeats

Question 4

What are some human viral diseases?

Answer 4

Influenza - caused by influenza virus, its genetic material changes from year to year
AIDS - caused by the HIV virus, and it attacks the white blood cells (immune system of the body)

Question 5

What is a vaccination?

Answer 5

Weakened virus injected into the body - this builds a defence mechanism

Question 6

What types of vaccinations are there?

Answer 6

Whole-agent vaccines - weakened virus is injected

Subunit vaccines - certain part of the virus is injected

Question 7

What is herd immunity?

Answer 7

If more people are vaccinated, it is harder for the virus to spread because there are less cells that it can infect successfully