Growing bacteria (triple)

What do you need to know?

Practical investigations on this topic can be examined in two different ways:

    1. Preparation of a sterile colony of bacteria
    2. Investigation into the effects of antibiotics or other chemicals

Students are often asked about precautions they can take

    • Sterilizing the inoculating loop with a flame or ethanol kills unwanted bacteria
    • Working near a flame causes convection currents to rise up so bacterial spores are carried away
    • Wearing gloves ONLY protects the scientist and DOES NOT reduce the chance of contaminating the culture

In an investigation

    • Samples are incubated at 20C to prevent growth of pathogens
    • Use π r2 to measure the area of bacterial colonies

1. Watch the video


2. Click here to try the practical for yourself.


3. Click here for the exambank pack for this practical

What type of organism is a bacterial cell?

Prokaryote (in the Kingdom Bacteria and the Domain Eubacteria)

What are the features of a bacterial cell?

No nucleus, but DNA is in plasmids or free floating

Cell wall made of peptidoglycan

Ribosomes


What is the name of the type of bacteria that is resistant to most antibiotics?

MRSA is the most common answer

C. difficile is another example that can be used.