science standard 5
TRANSCRIPT
Microorganisms
All living things are created by God. Humans, animals and plants are living things. They vary in size and can be seen with naked eyes. However, there are tiny living things that can only be seen through a microscope. These are called microorganisms.
Types of microorganisms
There are different types of microorganisms. They are bacteria, protozoa, fungi and virus.
Bacteria
Protozoa
Virus Fungus
Bacteria
Bacteria exist in different shapes, sizes and colours.
Protozoa
Most protozoa are found mainly in ponds, lakes and rivers. Some of them eat other microorganisms as food.
Fungi
Fungi can be found on mouldy bread, rotten food, trees and forest floors.
Virus
Virus is the tiniest microorganism. It can be found living in some fungi, protozoa, animals, plants and humans.
Just like other living things,microorganisms also undergo life process. They breathe, move and grow.
Microorganisms can breathe.
Yeast is an example of microorganism. It is a fungus. It is used to make bread. There are air spaces in the bread. The air spaces are caused by carbon dioxide gas given out whenthe yeast acts on the dough. This shows that microorganisms breath.
Microorganisms can grow
What happens when you leave a bowl of rice gor a few days? It will be covered with white patches. The patches that you see on the rice are actually fungi. The patches become bigger after sometime. This shows that microorganisms grow.
Microorganisms can move
These microorganisms do not have legs, but they are able to move.
Some microorganisms are useful
Tapai is a popular food in Malaysia. It is made from glutinous rice or tapioca. Yeast is added to make tapai.
Yeast is also added to make bread. Bacteria and fungi cause dead organisms
to decay to form natural fertelizers. Some bacteria can be used to make
cheese and bacteria. Fungi are used to produce antibiotics.
Microorganisms can be harmful
Some microorganisms that enter the body can cause illness.
Eating food contanimated with microorganisms can cause food poisoning.
Bacteria can acton the food remains between the teeth. This produces acid which causes tooth decay
Food turns bad because of bacteria and fungi.
Harmful microorganisms can cause disease
Some disease can easily spread from one person to another. They are called contagious diseases. Examples are influenza, measles, mumps and chicken pox.
How do microorganisms spread from one person to another?
Through food and drink. Sneezing or coughing. Direct contact. Carried by mosquitoes or flies. Microorganisms can also spread through
the air.
Howto prevent disease from spreading?
Wash your hands before handling food especially after using the toilet.
Drink water that has been boiled because boiling kills microorganisms.
Cover your mouth when coughing or sneezing to prevent microorganisms from spreading into the air.
Do not share personal items such as toothbrush, towel and comb.
Cover your wound to prevent it from infection.
Put patients with contagious diseases such as dengue fever, malaria, chicken pox, conjunctivitis or mumps into quarantine.