Transcript Unit 8C Lesson 1 Microbes Objectives: to learn that bacteria and

Unit 8C Lesson 1 Microbes
Objectives: to learn that bacteria and
viruses are responsible for disease.
Targets: 2, 5, and 6
Microbes
• When we say we get sick because of germs
what we really mean is that microbes or
micro-organisms are making us sick.
• There are two types of microbes which
make us sick:
– Bacteria
– Viruses
Bacteria
• Bacteria are single cells
much like the ones in our
body except that:
– They exist on their
own.
– They don’t have a
proper nucleus just
strands of DNA.
• Bacteria need a food
supply to give them
energy.
• It is bacteria which cause
our food to rot as they
use this food for
themselves.
Viruses
DNA
Protein
Coat
• Viruses are structures very
different from any other living
thing. In fact because they don’t
need food to survive there is
argument over whether they are
alive or not.
• They consist of two things:
– A hard shell made of
protein.
– Inside this shell is a strand
of DNA
• The virus needs this DNA to
reproduce itself but it cannot do
this on its own.
• In order to reproduce the virus
injects its DNA into our cells.
– The DNA reproduces and
makes new viruses.
– These viruses are then
released and infect new
cells.
Work to Do
•
•
•
•
Read pages 76 and 77
Copy and label figures 3 and 4
Complete questions 1-5 page 77.
Homework
– Complete Activity B7S1
– Define the following keywords:
• Bacterium, DNA, micro-organism, virus