SWBAT: Describe how a virus
can infect a host cell.
Initial Activity: Take out notebooks and be prepared to
take notes from the Brain Pop Video.
What are viruses?

A Virus is a non living particle. It is a
strand of hereditary material (Viral DNA)
surrounded by a protein coating.

A Virus multiplies by making copies of its
self inside the cells of a living thing.

These cells that become infected are
called host cells.
Active Virus

When a virus enters a cell, and it is active,
it causes the host cell to make more
viruses.

This process destroys the original host
cell and replaces it with copies of the
virus.
Latent Virus

Some viruses are inactive, these are called
latent. This means it does not start making
new viruses right away, and does not destroy
the host cell.

When the cell reproduces (or splits) the
virus gets copied. At any time, conditions
inside or outside the body can cause these
latent viruses to become active.
How do viruses affect organisms?

A virus can infect any living thing.

Viruses cannot move on their own. The
wind can carry a virus and an animal can
get a virus by inhaling it.
Treating and Preventing Disease

Antibiotics work well to treat bacteria
infections, they do not work on viruses.

Preventing is the best defense against a virus
because treating them can be very difficult.
Ways to prevent or protect people from viruses:
 Creating vaccines
 Washing hands/cleaning areas you touch
 Separating infected patients from healthy people
 Controlling animals that spread disease.
Natural Immunity and Vaccines

Our bodies can make interferons which
protect our cells from viruses.

Vaccines are used to prevent disease.
They are made from weakened particles
of virus to help your body to produce
interferons to fight infections.
Activity: How does a virus infect a
host cell?

Today you will be creating a comic describing the
way a virus invades a host cell, eventually destroying
it.

You must include Colorful diagrams or drawings (Be
creative! You can make literal drawings, make it like
a comic strip, etc.)

You must also describe in words what is occurring
along each step of the way ( 5 stages)

Label each part of the host cell/virus (use page 240
in the textbook to help)
Homework Review Virus Worksheet
(How does a virus infect a host cell?

Use page 240 in the science textbook to
help you answer the questions on the
worksheet.

This will be collected and graded.