Micro-organisms

S1 ScienceBiological Sciences

What are germs?

There are lots of different

types of germs.

Germs are all around us.

Germs are bad for us.

If we wash our hands

regularly, we won’t have

any germs on them.

Learning outcomes Success criteriaUnderstand what micro-organisms are.

Define the term “micro-organism”.

Name the four main types of micro-organism.

Describe examples of places where you can find micro-organisms.

Micro-organisms

• Micro-organisms are living things which can only be seen using a microscope.

• The four main types of micro-organism are: – Bacteria– Viruses– Fungi – Protists

Reading

http://www.bbc.co.uk/apps/ifl/learningzone/clips/queryengine?config=results_within&viewpage=1&SuppressCaching=1&ContentType=text%2Fhtml%3B+charset%3Dutf-8&oper_1=eq&attrib_1=SCHOOL_LEVEL_NAME&attrib_2=SUBJECT_NAME&oper_2=eq&attrib_3=TOPIC&oper_3=eq&page=1&

Microbes in your home

• Toilet• Rubbish bins• Front door/backdoor mat• Vacuum/cleaner• Clothes/Dish towels• Soap dispensers/taps• Tomato/brown sauce bottles• House/mobile phones• Work surfaces

Experiment

AIM: to investigate where micro-organisms are found in the classroom.

Pupil 1 Pupil 2

Where are these micro-organisms?

1. Label plate with you and your partners initials and the date.

2. Dip cotton bud in tap water.

3. Wipe test area with same bud.

4. Gently rub on your side of the plate.

5. Seal plates diametrically, small pieces!

6. Place in the tray upside down ready for incubation.

Learning outcomes Success criteriaUnderstand what micro-organisms are.

Define the term “micro-organism”.

Name the four main types of micro-organism.

Describe examples of places where you can find micro-organisms.

Useful and harmful micro-organisms

S1 ScienceBiological Sciences

Learning outcomes Success criteriaKnow examples of situations where micro-organisms can be

useful and harmful.

Describe one examples of a situation where each of the three types of micro-organism can be useful.

Describe one example of a situation where each of the three types of micro-organism can be harmful.

Micro-organism type

Harmful scenario Useful scenario

http://www.bbc.co.uk/schools/ks3bitesize/science/organisms_behaviour_health/disease/revise3.shtml

Learning outcomes Success criteriaKnow examples of situations where micro-organisms can be

useful and harmful.

Describe one examples of a situation where each of the three types of micro-organism can be useful.

Describe one example of a situation where each of the three types of micro-organism can be harmful.

Factors affecting the growth of micro-

organismsS1 Science

Biological Sciences

Learning outcomes Success criteriaKnow factors which can affect

the growth of micro-organisms. State three factors that are

required for the growth of micro-organisms.

State the effect of temperature on the growth of micro-organisms.

Experiment

1

2

3

Key

1

2

3

Bread

Bread + 10 drops water

Bread + 20 drops water

• What is the AIM of the experiment?

• What is your HYPOTHESIS?

• Write a METHOD (with a labelled diagram)

• Leave space for RESULTS and a CONCLUSION.

Results

Moisture content of bread (number of drops of water)

Observations regarding growth of

micro-organisms

0

10

20

Experiment

refrigerator

room

oven

Inoculate plates with yeast

• What is the AIM of the experiment?

• What is your HYPOTHESIS?

• Write a METHOD (with a labelled diagram)

• Leave space for RESULTS and a CONCLUSION.

• What do you think would happen to the growth of micro-organisms if you kept on increasing the temperature?

• Sketch a graph to show the effect of temperature of the rate of growth of micro-organisms.

Problem

• If a micro-organism reproduces once every 20 minutes, how many micro-organisms will there be after:

1. 6 hours2. 2 days3. 3 weeks

Learning outcomes Success criteriaKnow factors which can affect

the growth of micro-organisms. State three factors that are

required for the growth of micro-organisms.

State the effect of temperature on the growth of micro-organisms.

Can micro-organisms be removed?

S1 ScienceBiological Sciences

Learning outcomes Success criteriaKnow examples of situations where the growth of micro-organisms is related to personal hygiene and food safety.

Describe one example of a situation where the growth of micro-organisms is related to personal hygiene and one for food safety, mentioning:

–Where the micro-organisms have come from–Their source of food–The undesirable effect this can have

Know how micro-organisms can be removed.

Describe three measures that could be taken to remove micro-organisms, putting these in an order of how effective each one is.

Describe three examples of everyday situations where these steps are/should be put into practice.

Everyday situations involving micro-organisms

• Our bodies

• Food preparation surfaces

• Surgical equipment

Deodorant vs antiperspirant

Experiment

• Dampen swab• Rub over test area• Streak on agar• Discard swab

• Wipe same test area with water• Dampen swab• Rub over test area• Streak on agar• Discard swab

• Wipe same test area with cleanser• Dampen swab• Rub over test area• Streak on agar• Discard swab

Learning outcomes Success criteriaKnow examples of situations where the growth of micro-organisms is related to personal hygiene and food safety.

Describe one example of a situation where the growth of micro-organisms is related to personal hygiene and one for food safety, mentioning:

–Where the micro-organisms have come from–Their source of food–The undesirable effect this can have

Know how micro-organisms can be removed.

Describe three measures that could be taken to remove micro-organisms, putting these in an order of how effective each one is.

Describe three examples of everyday situations where these steps are/should be put into practice.