Let’s learn how to stay healthy and stop germs from spreading! 💪🌿
You’re getting great at learning science words! 🎉
Diseases stop our bodies from working properly. There are different kinds of living things that cause disease. They infect other living things and grow and reproduce on or in the body of the living thing that they infect. Any living thing that lives on or in the body of another living thing is called a parasite. The living thing that a parasite infects is called the host.
Bacteria are very small living things that we can only see using a microscope. Bacteria cause diseases such as cholera and pneumonia. Not all bacteria are harmful — some are even useful to humans!
Viruses are even smaller than bacteria. All viruses are harmful and can cause diseases in humans, animals, and plants. Some viruses even infect bacteria! Humans get flu, chickenpox, and measles from viruses.
The yeast that we use to make bread rise is a fungus. Mushrooms that we eat are also fungi. But some fungi are parasites that cause diseases. Ringworm in humans and animals, athlete’s foot in humans, and rusts in plants are caused by fungi.
There are also other kinds of parasites that cause infectious diseases. Malaria and dysentery are two examples of diseases caused by these parasites.
1a. What is a parasite?
1b. Why are viruses and some bacteria and fungi parasites?
2. Make a table of the different kinds of living things that cause diseases and name two examples of a disease that each one causes.
Type of Microorganism | Examples of Diseases |
---|---|
Bacteria | Cholera, Pneumonia |
Virus | Flu, Measles |
Fungus | Ringworm, Athlete’s foot |
Parasite | Malaria, Dysentery |
Well done! You now know how different microbes cause different diseases. 👏
Our body has many ways to stop us from being infected by diseases. These ways are called the body’s defences against diseases.
Tears contain a special chemical that can kill some bacteria, helping to keep our eyes clean and safe.
Sticky mucus in our noses, windpipe, and other air passages traps germs so they don’t reach our lungs.
The skin acts like a strong barrier that stops most germs from getting inside the body.
Acid in the stomach kills many germs that may be on food we have eaten.
Diseases can be spread by body contact and in food, in water and in the air. There are different ways we can help to control the spread of diseases.
Many diseases are spread in food, water and body fluids. We can help prevent the diseases from spreading by good hygiene. This means keeping yourself and the things around you clean.
These are some of the things we can do:
Class 5 did a survey of people in their local community to find out which hygiene methods people used. These are their results.
Method to prevent infectious diseases | Number of people who use the method |
---|---|
wash hands after going to toilet | 10 |
wash hands before working with food | 5 |
wash hands after working with food | 4 |
keep the kitchen, toilet and surroundings clean | 12 |
cover nose and mouth when coughing or sneezing | 7 |
📝 Your tasks:
💬 How are we doing? Ask your partner:
Great work analyzing real data like a scientist! 🌟
Some serious diseases, such as malaria, yellow fever, and sleeping sickness, are spread by insects. Malaria and yellow fever are spread by mosquitoes, while sleeping sickness is spread by the tsetse fly. The insects do not cause the disease, but they spread the disease parasite when they bite. The insects themselves do not get the disease — we call such insects vectors.
The best way to prevent diseases spread by insects is to avoid being bitten. Here are some helpful ways to stay safe: