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Page 1

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B1 1.1
Friday, May 04, 2012
4:05 PM
Diet and exercise



A healthy diet has the right balance of food types. Carbohydrate, fat
and protein are used by the body to release energy and build cells.
Mineral ions and vitamins are needed to keep the body healthy. If the
diet…

Page 2

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B1 1.2
20 May 2012
14:40

Weight problems



It is important for good health to get the energy balance correct.
If the energy you take in equals the energy you use then your mass
will stay the same. Eating too much food can lead to becoming
overweight and obese.
Long…

Page 3

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B1 1.3
20 May 2012
14:46

Inheritance, exercise and health



Your metabolic rate can be affected by the genes you inherit from your
parents.
There are 2 types of cholesterol. You need 'good' cholesterol for your
cell membranes to make vital substances.
Small numbers of the population inherit high levels…

Page 4

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B1 1.4
20 May 2012
14:53


Pathogens cause infectious diseases.
Pathogens are tiny microorganisms - usually bacteria or viruses.
When bacteria or viruses enter the body they reproduce rapidly. They
can make you feel ill by producing toxins (poisons).
Viruses are much smaller than bacteria and reproduce inside cells. The…

Page 5

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B1 1.5
20 May 2012
14:59

Defence mechanisms



The skin prevents pathogens getting into the body.
Pathogens are also trapped by mucus and killed in stomach acid.
White blood cells are part of the immune system. They do three things
to defend the body:
They ingest pathogens. This means they…

Page 6

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B1 1.6
20 May 2012
15:07


Using drugs to treat diseases




Antibiotics kill infective bacteria in the body.
Penicillin is an antibiotic, but there are many others. It was
discovered by Alexander Fleming in 1928.
Viruses are difficult to kill because they reproduce inside the body
cells, so any treatment…

Page 7

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B1 1.7
20 May 2012
15:15

Growing and investigating bacteria




Pure cultures of non-pathogenic bacteria can be used for laboratory
investigations.
A culture of microorganisms can be used to find the effect of
antibiotics on bacteria.
Investigations need uncontaminated cultures of microorganisms. Strict
health and safety procedures are used to…

Page 8

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B1 1.8
20 May 2012
15:25

Changing pathogens


Some pathogens, particularly viruses, can mutate resulting in a new
form called a mutation.
Very few people are immune to these changed pathogens so disease can
spread quickly.
Diseases that spread within a country result in an epidemic. Those
that spread across…

Page 9

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B1 1.9
20 May 2012
15:31

Immunity



Dead or inactive forms of a pathogen are used to make a vaccine.
Vaccines can be injected into the body.
The white blood cells react by producing antibodies.
This makes the person immune. It prevents further infection because
the body responds quickly by…

Page 10

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B1 1.10
20 May 2012
15:37

How do we deal with disease?



Most people in a population need to be vaccinated to protect society
from very serious diseases.
Diseases such as measles can lead to long term damage to the body,
such as deafness and occasionally death.
Some vaccines cause…

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