Killing bacteria
C3
Unit 2 Task 3
Name: __________________
Class: ___________
1 This list gives several ways in which bacteria can be killed.
disinfectant
sterilizing
antiseptic
antibiotic
adding chlorine
heating thoroughly
Copy and complete the table, using the words above.
Source of bacteria
Best way to kill the bacteria
Tap water
Raw chicken
Cut finger
Surgeon’s scalpel
Infection in your blood
Kitchen waste bin
2 Sita caught a virus that gave her polio. Akpata caught a bacterium that gave her
pneumonia. They both took antibiotics.
Copy and complete these sentences:
a Sita stayed ill because …
b Akpata quickly got better because …
CORE
3 Dr Fleming’s patient, Joan, had a lung infection.
Dr Fleming sent samples of her phlegm to the
hospital laboratory. In the lab, the scientists grew
the bacteria on agar plates. In the middle of each
plate they put one drop of antibiotic solution. They
used a different antibiotic on each plate.
Look at the diagrams. They show the lab results
after two days. The spots show where the antibiotic
drop was put. The shaded areas show where
bacteria have grown.
© Harcourt Education Ltd 2004 Catalyst 2
This worksheet may have been altered from the original on the CD-ROM.
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Sheet 1 of 2
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C3
Killing bacteria (continued)
Unit 2 Task 3
a Which antibiotics could Dr Fleming prescribe for his patient?
b Which antibiotic would be best? Explain your answer
c Which antibiotics should Dr Fleming avoid? Explain your answer
d Joan is allergic to antibiotic B but not to the others. It causes a very itchy rash all over
her body. Normally it is given as a course of tablets lasting for seven days.
i Which antibiotic should Dr Fleming use instead?
ii Why will Dr Fleming prescribe a 14-day course of this antibiotic?
iii What would Dr Fleming have done if he only wanted Joan to take the tablets for
seven days?
e Joan went to a family party, the day after she first became unwell. Four members of her
family became ill a few days later. Explain how they became ill.
EXTENSION
4 Animals that are reared in intensive farming conditions often have feeds containing low
doses of antibiotics, which make them grow faster.
a Other than growth, why might it be necessary to add antibiotics to feedstuff for intensive
farming?
b Doctors are finding that some bacteria are becoming harder to destroy.
Explain how adding antibiotics to animal feed might be an important factor in this proble
m.
5 In 2003, a new illness called the SARS (severe acute respiratory syndrome) virus appeared
in China. It quickly spread to most of the Far East and also appeared in Canada. Many
people became ill and some died.
a Hospitals did not prescribe antibiotics to SARS patients. Explain why not.
b Television pictures from infected areas showed people wearing medical facemasks in
towns and at work.
Why did they think this would help?
c Most people who caught SARS eventually got better. Why are they unlikely to catch
SARS again?
d What would hospitals do to try to make sure that a SARS patient did not infect everyone
else?
e i Some diseases, like AIDS, can be helped by prescribing antiviral drugs. How can
antiviral drugs help?
ii Why don’t doctors prescribe antiviral drugs for colds and flu?
© Harcourt Education Ltd 2004 Catalyst 2
This worksheet may have been altered from the original on the CD-ROM.