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Experiment : Investigating the Presence of Micro-organisms in the Different Soil Layers
Name: Class:
School: Date:


Soil Sample A

Soil Sample B

Soil Sample C

Soil Sample D


What has happened to the control Petri dish? Does this mean your results are valid or invalid?


Are there any differences between the number of colonies of micro-organisms which have grown in the four Petri dishes? Explain any differences you observe.


When you look at soil you cannot see micro-organisms with the naked eye. Why can you see the micro-organisms in the Petri dishes?