Living things such as microorganisms can only be seen under a microscope. These are found everywhere. Some of them, like yeast are helpful and some of them are harmful and disease causing, like bacteria.
There are three types of microorganism:
Microorganisms that cause diseases are often called germs.
Some diseases, like flu, are caused by viruses. Diseases caused by viruses usually spread easily from one person to another.
Uncooked foods can contain bacteria. The bacteria are killed when the food is cooked properly. But if we eat food that has not been cooked properly, the bacteria may survive and cause illness.
Mould is a type of microorganism that grows on decaying food. It can make us ill if we eat it.
How to avoid spreading harmful microorganisms
You can avoid spreading harmful microorganisms by:
* Washing hands before eating, after preparing food and after using the toilet.
* Covering mouth when coughing and sneezing.
* Keep away from people suffering from infection.
* Not eating food which is not cooked properly.
* When bread is made, a microorganisms called yeast is added to the dough to make the bread rise.
* Yoghurt is made by boiling milk and adding bacteria to it.
* Inside a pile of dead leaves are millions of tiny bacteria. These bacteria feed on the leaves and break them down into nutrients. The nutrients go back into the soil and make it more fertile.
Collect pictures of different microorganisms.
(OHP required to demonstrate skeleton parts)
Skeleton is made from bones. Movement is caused by joints and muscles. As we grow, our bones grow too.
* Skeletons and muscles
* Human life cycle
Skeletons and muscles
Many animals have skeletons to support and protect their body and to help it move.