1. Virus Notes

2. Virus Notes:
Viruses are NOT composed of cells.
A virus requires a host to make a copy of itself.
3. A virus can act one of two ways once it is inside of a host. It can become active or it can become latent (which is an inactive/dormant stage).

3. Active Virus
The active cycle is also know as the Lytic Cycle.
An active virus multiplies and destroys the host cell.
The virus attaches to the host.
The hereditary material of the virus enters the host cell.
The hereditary material of the virus causes the cell to make VIRAL hereditary material and proteins.
New viruses form inside of the host cell.
New viruses are released as the host cell bursts open and is destroyed.

4. Lytic or Active Phase of a Virus Draw this in the box in your notes
Lytic or Active Phase of a Virus Draw this in the box in your notes. Be sure to label all steps.
Virus attaches to host cell.
The virus injects its own DNA into host cell.
Virus DNA uses the host’s nucleus to create copies of the viruses DNA>
The virus directs the cell to assemble more viruses inside the cell.
The host cell bursts open releasing thousands of newly formed viruses. 1. 2. 3. 5. 4.

5. Latent (or inactive) Virus
The latent cycle is also known as the Lysogenic Cycle.
The hereditary material of the virus becomes part of the host cell's hereditary material.
As the host cell reproduces, the viral DNA/RNA is copied too.
A latent virus may be DORMANT for many years.
Outside factors induce the virus to become active.
When this occurs, the virus becomes active and the host cell is destroyed when the virus is released.

6. Latent or Lysogenic Cycle of a Virus Draw this diagram in the box in your notes with all the labels.
Virus is latent/inactive until step 6
A host cell
A host cell
A host cell

7. FACTS ABOUT VIRUSES Viruses affect ALL living things.
A virus that attacks a bacteria is called a bacteriophage.
A vaccine is used to PREVENT a disease.
Edward Jenner is credited with developing the first vaccine.
Antibiotics are used to TREAT bacterial infections.

8. FACTS ABOUT VIRUSES continued:
A virus is made of a strand of DNA or RNA (hereditary material) surrounded by a protein coat.
Scientist hope to help people with genetic disorders and to find a cure for cancer by using gene therapy.
Virology is the branch of science that deals with the study of viruses.

9. Are Viruses alive? Yes or No (pick one)
Explain your answer using the characteristics of life. (remember these?)
Made of cells
responds to the environment
growth and development
ability to reproduce
Uses energy
The chemicals of life

10. 1. In which diagram is a virus attaching itself to a cell?
2. In which diagram are new protein coats and RNA and DNA cores being made?
3. In which diagram are new viruses being released from the host?
4. In which diagram has the virus entered the cell?

11. https://assignments.discoveryeducation.com/?cdPasscode=TB8BD-4A64