Species at war
Information sheets and question sheets
Subject(s):
Science: Biology
Age group(s):
12–14
Microorganisms, pathogens
and the body’s defences
Topic(s):
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
This project and its actions were made possible due to co-financing by the
European Fund for the Integration of Third-Country Nationals
Microorganisms: information sheet
Microorganisms are very small living things.
You need a microscope to see most of them.
micro = very small
organism = something alive
Sometimes they are called microbes.
microscope
Bacteria 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.
bacteria
Viruses 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.
viruses
You 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 singlecelled organisms.
Viruses are larger than
bacteria.
Some fungi are useful.
Choose a word.
 cells
Write the correct word in the space.
 viruses
_____________________ are very small living
 protein
things. __________, __________ and fungi are
 single-celled
 fungi
 genetic
examples of these. Bacteria are ______________.
Viruses are not made of _______________ . They
 bacteria
have a ______________ coat round their
 microorganisms
_______________ material. Some bacteria and
_______________ are useful.
Pathogens: information sheet
Microorganisms 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:
warmth
moisture
nutrients (food for
growth)
Diseases are caused by:
Viruses attack and invade our body cells and
damage them.
virus
cell
s
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 sheet
List the three types of pathogens.
1.
2.
3.
Choose a word.
 damage
 invade
 virus
 toxins
 microorganisms
 diseases
Write the correct word in the space.
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
F
N
K
O
N
L
E
M
________________
T
S
K
I
N
S
G
C
R
H
T
U
O
M
S
U
V
A
W
N
H
______________
A
E
T
L
I
L
O
S
G
E
S
R
A
E
______________
P
W
Z
F
N
P
Q
______________
______________
______________
Transmission of microorganisms: information sheet
Some 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 sheet
Write 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
By animals
The body’s defences, 1: information sheet
The 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.
barrier
skin
scab
tears
sweat
Tears and sweat contain
chemicals which destroy bacteria.
Stomach acid destroys bacteria in
food.
stomach
Sticky 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 sheet
Complete the names of the 5 ‘barriers’ which the body uses to
prevent microbes from entering the body.
1. s _ _ _ _ _ _
a___
2. t _ _ _ _
4.
m____
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.
Mucus
Skin
Stomach acid
A scab
1.
2.
3.
4.
seals
destroys
traps
prevents
bacteria in food.
a cut.
microbes from entering the body.
microorganisms.
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
Yellow phagocyte engulfs the
destroy pathogens by engulfing them.
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. Tcells 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 receptors
After 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 sheet
Antibiotics 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 antibiotic
germs. A few are
as well as the good bacteria resistant bacteria
antibiotic 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 sheet
Read 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.
Across
2. 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.
Down
1. 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.