Notes from 5-6

2.  Non-living
 Tiny
 Genetic material protected by a protein
coat
 Unable to reproduce on their own

3.  Lack characteristics of living things:
› are not cells
› don’t use their own energy to grow or
respond to surroundings
› cannot make food, take in food or produce
wastes
› cannot reproduce on their own

4.  Bacteriophages
 Spherical (RNA)
 Crystal (stable. Polio)
 Cylinder (plant)

5.  Two parts: core of genetic material & a
protein coat with surface proteins
 The virus surface proteins, like keys, only fit
into certain host cells
› Ex. HIV infects the cells of the immune system

6.  Can cause disease
› Once recovered from a viral illness the body
becomes immune
 Useful
› Vaccines, built from viruses, are used to
cause immunity in organisms so they cannot
be made ill from a virus
› Gene therapy uses the viral mechanism for
infection to deliver new genetic material to
cells that need it