This project and its actions were made possible due to co-financing by the European Fund for the Integration of Third-Country Nationals

Source | This resource was originally developed by Ann Horton and adapted by the EAL Nexus team.License information | This resource is free to use for educational purposes. ©British Council 2015

Species at war

Information sheets and question sheets

Subject(s): Science: BiologyAge group(s): 12–14

Topic(s): Microorganisms, pathogens and the body’s defences

Microorganisms: information sheetMicroorganisms are very small living things.You need a microscope to see most of them.

micro = very smallorganism = something alive

Sometimes they are called microbes.

microscopeBacteria are very small.

They are single-celled organisms.

They have a cell wall. They do not have a nucleus. Some bacteria are useful. Some bacteria cause disease.

bacteriaViruses are extremely small.

They are much smaller than bacteria.

They are not made of cells. They have a protein coat

round their genetic material. Viruses cause disease.

virusesYou can see some fungi without a microscope.

Some fungi are single-celled organisms.

Some are made of long threads.

Some fungi are useful. Some fungi cause disease.

fungi

Microorganisms: question sheet

List the three types of microorganism.

Smallest

Biggest

Tick true or false. True False Correct the false sentences.Viruses are made of cells.All bacteria cause disease.Bacteria are single-celled organisms.Viruses are larger than bacteria.Some fungi are useful.

Choose a word. Write the correct word in the space. cells viruses protein single-celled fungi genetic bacteria microorganisms

_____________________ are very small living things. __________, __________ and fungi are examples of these. Bacteria are ______________. Viruses are not made of _______________ . They have a ______________ coat round their _______________ material. Some bacteria and _______________ are useful.

Pathogens: information sheetMicroorganisms that cause disease are called pathogens (microbes).Microorganisms cause diseases in different ways:

Influenza (flu) is caused by a virus.

Salmonella (food poisoning) is caused by bacteria.

Athlete’s foot is caused by a fungus.

Microorganisms need three things to help them reproduce:

warmthmoisture nutrients (food for

growth)Diseases are caused by:Viruses attack and invade our body cells and damage them.

Bacteria produce toxins (poisonous chemicals) which make us ill.Fungal infections are spread through direct contact (by sharing towels).Microorganisms can enter our body in many different places:

genitals

nose ears

mouth eyes

cut skin

Pathogens: question sheetList the three types of pathogens.

1. 2. 3.

virus cell

Choose a word. Write the correct word in the space. damage invade virus toxins microorganism

s diseases

Pathogens are ___________________ that cause disease. Different pathogens cause different _______________ . For example, influenza is caused by a _______________ .Bacteria produce _______________ which make us ill. Viruses attack and ___________ our body cells and _______________ them.

Microorganisms can enter our body in different places. Find the 7 places in the wordsearch. The first one has been done for you.Find the words here. Write the words

here.B C F G T U S eyes

______________________________________________________________________________________

S E Y E P Y FN K O N L E MT S K I N S GC R H T U O MS U V A W N HA E T L I L OS G E S R A EP W Z F N P Q

Transmission of microorganisms: information sheetSome diseases are infectious. That means you can catch them from someone else.

Pathogens are transmitted (passed on) from one person to another in a number of ways.By breathing droplets

By eating or drinking contaminated food or liquid

By touch (physical contact)

By insects or animals

By blood

From mother to child

Salmonella is a bacteria. It is passed on by eating contaminated food.

Influenza (flu) is a virus. It is passed on by droplets in the air from an infected person, or by physical contact.

Athlete’s foot is a fungus. It is passed on by physical contact.

It is very important to wash your hands after you use the toilet and before you eat.

Transmission of microorganisms: question sheetWrite the following sentence out correctly:you can catch/is a disease that/from someone else./An infectious disease____________________________________________________________________________________________________

The pictures below show the ways in which diseases can be transmitted (passed from one person to another).Match each picture to its correct description.

by insects or animals

by blood

from mother to child

by touch (physical contact)

by breathing droplets

by eating or drinking contaminated food or liquid

The body’s defences, 1: information sheetThe human body has a number of ‘barriers’ which form the first line of defence

against pathogens.They help to prevent many pathogens from entering the body.The skin prevents microbes from getting into the blood. If you cut yourself, platelets in the blood stick together to form a clot. They seal the cut with a scab to stop microbes getting in. skin scabTears and sweat contain chemicals which destroy bacteria.

tears sweatStomach acid destroys bacteria in food.

stomachSticky mucus in your nose and airways helps to trap microorganisms. Tiny hairs called cilia then move the mucus on.

mucus cilia (tiny hairs in the nose)

The body’s defences, 1: question sheetComplete the names of the 5 ‘barriers’ which the body uses to prevent microbes from entering the body.

barrier

1. s _ _ _ _ _ _ a _ _ _ 4. m _ _ _ _

2. t _ _ _ _ 5. s _ _ _ _

3. s _ _ _

Match the “barrier” to the part(s) of the body where it is found.tear all over the body

acid nose and airways

skin stomach

mucus eyes

Write out 4 correct sentences about the body’s ‘barriers’.Use a word or phrase from each column.MucusSkinStomach acidA scab

sealsdestroystrapsprevents

bacteria in food.a cut.microbes from entering the body.microorganisms.

1.2.3.4.

The body’s defences, 2: information sheet

If pathogens get past the first line of defence and enter your body, there is a second line of defence: the immune system. The white blood cells are a vital part of the immune system. They fight infections in our bodies. Phagocytes are one type of white blood cell. They destroy pathogens by engulfing them. Yellow phagocyte engulfs the

pathogen

B-cells and T-cells are another type of white blood cell (lymphocytes). Each pathogen leaves an antigen on the surface of cells it infects. T-cells recognise the pathogens by receptors on their surface. B-cells produce antibodies. They are Y-shaped. These antibodies lock on to the antigens. The antigens can then be destroyed in different ways. Each antibody is specific to one antigen. This means that each antibody can only lock on to just one type of antigen.

Different B-cells with antigen receptorsAfter the immune system has produced antibodies for one illness, some of the antibodies remain as ‘memory cells’. This means that your body will react more quickly to fight off that illness if you meet it again.

The body’s defences, 2: question sheet

The sentences below all contain a mistake. Write each sentence out with the CORRECT facts.

1. Phagocytes are a type of pathogen._______________________________________________________________________________________________

2. T-cells produce antibodies._______________________________________________________________________________________________

3. Antibodies are many different shapes.______________________________________________________________________________________________

4. Antibodies can lock on to any antigen.______________________________________________________________________________________________

The sentences below describe what happens when pathogens attack a person’s body and the immune system fights them. They are in the wrong order.The antibodies help to destroy the pathogens.T-cells recognise the pathogens.Pathogens enter the body.The person begins to feel well again.B-cells make antibodies.The pathogens reproduce and make toxins.Write them out in the CORRECT order here.

1.

2.

3.

4.

5.

6.

Antibiotics and vaccines: information sheetAntibiotics are medicines that are prescribed by doctors. They do not affect viruses, so are not prescribed for colds or flu.

Antibiotics kill bacteria Antibiotics stop bacteria from growing.Some types of bacteria are no longer affected by certain antibiotics.This is called antibiotic resistance. This can be a problem, as some people might not be able to fight infections themselves, without the help of effective antibiotics.

There are lots of Antibiotics kill the illness The antibioticgerms. A few are as well as the good bacteria resistant bacteriaantibiotic resistant. protecting the body. grow.Vaccines are another way of helping your immune system to fight some diseases. The process is called vaccination or immunisation.Dead or inactive microbes are injected into your body. You do not become ill, because the microbes are not active, but your immune system produces antibodies to fight the microbes. This means that if this disease ever infects your body, you already have the antibodies there to fight it off.Antibiotics and vaccines: question sheetRead the paragraph below. Cross out the wrong word in each pair of bold and italic words. The first one has been done for you.Antibiotics and fungi / vaccines can help your immune /

digestive system to fight diseases. Antibiotics are medicines / pathogens which can kill viruses / bacteria but not viruses / bacteria. Unfortunately, some bacteria have become natural / resistant to certain antibiotics, so they can no longer be killed by them. Vaccines contain dead or inactive / live microbes which make your immune system react to them and produce antigens / antibodies. If the real, active disease tries to infect you after that, the pathogens / antibodies will fight it off.

Across2. Bacteria which are not affected by a particular antibiotic.6. These can be killed by antibiotics.7. A microorganism which is not affected by antibiotics.Down1. A form of a pathogen which will not give you the disease it causes.3. Drugs which kill or weaken bacteria.4. White blood cells make these to destroy microorganisms.5. Contain inactive or dead microbes.