Download Year 8 * the human body Part C: Disease and Immunity

Term 2, 2012
WOODLEIGH
SCHOOL
YEAR 8 – THE HUMAN BODY
PART C: DISEASE AND IMMUNITY
Science Faculty
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DISEASE AND THE IMMUNE SYSTEM
SCIENCE IN ACTION: IMMUNITY OUR PROTECTION
Sir Gustav Nossal, a noted Australian scientist, was Australian of the Year in 2000. Sir Gustav
received this award for his lifetime’s work in medical research as an immunologist—a person
who studies immunity or the resistance to disease.
Our bodies recognise foreign antigens (proteins) on the cells of bacteria and viruses, and
make antibodies to destroy them. Once antibodies have been produced against a virus, for
example the measles virus, the body retains a memory of this is, so that if the virus comes
back again, the body can produce antibodies very quickly to destroy the virus before it can
take hold.
This is why we usually get a disease like the measles only once. This is called immunity.
Because so many children used to die from childhood diseases, scientists developed a way of
exposing the child to a disease without them getting the disease itself. This is called
immunisation. A small amount of antigen is taken from the organism that causes the
disease. This is the vaccine. It is then injected into the child’s body, and the child then
produces antibodies against the disease.
If enough children are immunised, infectious diseases such as measles and whooping cough
can be kept under control, and, hopefully, eliminated in the future. For that to happen, over
95% of children need to be immunised. In the past, immunisation programs have reduced
the incidence of diseases such as whooping cough (pertussis).
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However, in 1996 there were 1007 cases of whooping cough reported in Victoria.
Immunisation rates in Australia had fallen to a low of 52% by 1997. Because of the threat of
outbreaks of disease, the Australian Government is encouraging parents to make sure that
their children are fully immunised.
Questions
1. What is immunology?
2.
Explain what is meant by immunity.
3.
What is the difference between antibodies and antigens?
4.
Why is immunisation important?
5.
Babies can now have the hepatitis B vaccination soon after they are born. What are
the symptoms of hepatitis B?
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MY FAVORITE DISEASE
Your Task
Working on your own or as pairs you are to investigate a disease and give a report to the
class either as:
 A short presentation report. For example, a poster (including 250 – 400 words), web
page (with 250 – 400 words) or power point presentation (of about 6 – 8 slides with
about 250 – 400 words), or
 A short research report of between 600 – 700 words including relevant tables,
diagrams and flow charts.
First - Choose a disease that is caused by a pathogen (a disease causing agent such as a
bacteria or virus).
Include the following information in your report:
1. The common and scientific name of the pathogen.
2. How the pathogen causes the disease in the host. Why do you feel sick?
3. Symptoms of the disease. What happens when you are infected?
4. How the pathogen is distributed. How does it get from one host to the next?
5. How does the first line of defence usually protect you against this disease?
6. How do the second and third lines of defence keep you well, if the pathogen gets
past the first line of defence.
7. What can be done for you if you have the disease? How can you be helped not to
get it and how can you be helped if you do get it?
Good diseases to investigate are Mumps, Measles, Chicken Pox, Glandular Fever, Malaria,
Cholera, Influenza, Tetanus, Diptheria, Ebola, HIV/AIDS, Syphillis, Gonorrhea, to name a few.
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Marking Scheme
Criterion 1.
Collect the information you need for
the project.
The seven
The answers to
questions are all
the seven
answered
questions display
correctly.
a detailed
knowledge of the
relationship
between the
host and the
pathogen.
1
1
2
2
3
3
4
5
6
Criterion 2.
Use of the scientific language
Criterion 3.
Presentation
The key
concepts
have been
identified.
The report
logically
presents the
answers to
the
questions,
using
references.
The report is
presented in
a neat and
attractive
manner.
1
2
3
4
5
1
2
1
2
3
4
The key
concepts
have been
explained
correctly in
the
answers to
the
questions.
1
2
3
Any issues
have been
identified
and
discussed.
1
2
Total Score
5
Student Designed Experiment: Catching Bacteria
Where do you find bacteria? How would you catch them? As a whole class we will design a system to catch
bacteria and then try and work out where they can be found at Woodleigh School.
You will need:
Hypothesis
Aim
Method
Safety
Materials
Results/Observations
Discussion/Conclusion
Student Designed Experiment: Killing Bacteria
Many people believe that they can control the spread of bacteria using all sorts of things: Disinfectants, Antibiotics, Garlic, etc.
Design an experiment to test which substances are most effective at controlling the growth and spread of
bacteria.
You will need:
Hypothesis
Aim
Method
Safety
Materials
Results/Observations
Discussion/Conclusion
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