Micro-organisms

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Micro-organisms
In this unit children learn that there are many
very small organisms called micro-organisms
which feed, grow and reproduce and which may be
harmful or beneficial.
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Micro-organisms
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What makes you ill? Discuss.
Micro-organisms can enter the body and make us
feel ill. A micro-organism is the term given to
anything too small to see without the use of a
microscope. Often when the term micro-organism
or microbe is used we mainly think of bacteria
and viruses-in other words germs.
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Bacteria can cause diseases in humans which can
then spread from one person to another.
What precautions should you take to stop
bacteria spreading when you have a cold?
What illnesses do you know that are caused by
micro-organisms?
Use a tissue to cover your face when you sneeze
or cough
Stomach Flu
Wash your hands
Did you know that tooth decay was caused by
micro-organisms? How can you prevent this decay
and gum disease?
Brush your teeth
Use antiseptic mouthwash
Floss daily
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Bacteria in your stomach actually helps break
down the food you eat. However, there are some
bacteria, such a E coli that grow on meats,
eggs, or raw foods, that can be very dangerous.
Staph bacteria can cause pimples on your skin.
Staph can also cause harm to your blood, bones,
and lungs.
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Some kinds of bacteria can make you sick.
Some kinds can be helpful. Some bacteria
cause mold. Believe or not some molds are
helpful.
Some molds are also harmless. This is blue mold
on cheese. Otherwise known as "blue cheese".
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Helpful Microorganisms
Some bacteria turn milk into yogurt.
Some bacteria help break down the foods we eat.
Bacteria can help make certain kinds of cheeses.
Some bacteria cause mold that can be turned
into medicine such as penicillin.
Fungi like YEAST help bread dough rise.
Fungi help dead things decay and help remove
waste from Earth.
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Not all moldy food is good. Look at the moldy
food. What has caused this decay?
Place the words in the gaps.
Bacteria can also make food turn bad. ________
can float in the ___ and land on food that is
________. They then _________ very quickly and
feed on the food, making it go bad. This ____
food will make humans very ___ if they eat it.
uncovered
reproduce
ill
air
bad
Bacteria
Where can we put some sealed containers of food
to observe what happens?
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Review of the Kinds of Microorganisms
Bacteria A single-celled organism that can be
helpful and harmful.
Mold and Yeast are fungi. Fungi look like little
plants. But a fungus is not a plant. A fungus
cannot make its own food the way a plant does.
Fungi are decomposers. They break down dead
matter.
Protists are also microorganisms. Algae are a
kind of protist. Some protist can make their
own food. Other protists must hunt for food.
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Some algae can kill fish and cause a red tide.
The ocean water looks red when the algae grown
too fast.
Phytoplankton is also made of microorganisms. It
is also found in the ocean. It helps to make
the oxygen we breathe. It is is also the main
food for tiny fish. Without phytoplankton,
there would be fewer fish in the ocean.
Protists
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There are many ways in which we can preserve food
to stop it going bad.
Here are a few. Can you guess what the missing
words are?
Heat the food well to kill the bacteria. Then
put it into a clean, sealed container to stop
the bacteria landing on it. Keep the food very
cold. The cold does not kill the bacteria, but
it stops them from reproducing. Dry the food
out so that there is no water for the bacteria to
live on. Make any food that is going to be
kept for a while very sugary, because bacteria
cannot survive in very strong solutions.
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Some micro-organisms, such as yeast, can be very
useful. Yeast is found in bread, beer and wine.
Some bacteria is used in the production of
cheese and yogurt. Can you find out any more?
Yeast Let's set up some experiments to see
which conditions the yeast needs to live.
1) Try yeast with and without sugar
(food). 2) Compare warm and cold
conditions. What gas is produced?
Investigation Tips J Fair Test K Write down
observations J Think about how you are going to
record the results, what about a graph?
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Have you been listening?
Use the words below to complete the paragraph.
Some micro-organisms are use for making_______,
such as bread. Yogurt is made by
adding________to warmed milk. Bacteria also
helps to break down________. We have special
micro-organisms in our__________to help us
digest our food. Micro-organisms can also be
dangerous. Bacteria can make people_______.
Always_______your hands before you prepare food,
otherwise bacteria on your hands can give people
stomach__________.
sick
waste
stomachs
wash
bacteria
food
upsets
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What about these? 1Which type of micro-organism
is used to make yogurt? 2Why should you wash
your hands before preparing food? 3Which
micro-organism breaks down waste? 4Name a drink
made using micro-organisms. 5Which types of
micro-organism can make people ill? 6Name a food
made using micro-organisms.
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ONE FINAL JOB!
True or False? You match them.
1)Some micro-organisms are used for making food,
such as bread and yogurt. 2)We have special
micro-organisms in our noses to help us to digest
our food. 3)Bacteria can make people very
ill. 4)You should never wash your hands before
you prepare food, because bacteria is good for
you. 5)Viruses make people ill. They cause
illnesses such as colds and flus.

TRUE
FALSE
TRUE
TRUE
FALSE
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