RP3 - DNA Extraction (OCR Gateway GCSE Biology)

The first step in this experiment is to...

• filter the mixture

• mash the fruit

• add cold ethanol

• add salt and detergent

Why is detergent added?

• to break down cell membranes and nuclear membranes

• to cause DNA to stick together

• to remove insoluble parts of the cell

• to cause DNA to precipitate

Why is salt added?

• to break down cell membranes and nuclear membranes

• to cause DNA to stick together

• to remove insoluble parts of the cell

• to cause DNA to precipitate

Why is the mixture of mashed fruit, salt and detergent filtered?

• to break down cell membranes and nuclear membranes

• to cause DNA to stick together

• to remove insoluble parts of the cell

• to cause DNA to precipitate

Why is cold ethanol added?

• to break down cell membranes and nuclear membranes

• to cause DNA to stick together

• to remove insoluble parts of the cell

• to cause DNA to precipitate

DNA will appear as...

• white powder

• multicoloured single helix

• multicoloured double helix

• stringy white precipitate

DNA can be removed from the test tube using...

• a glass rod

• a magnet

• Bunsen burner

• electric water bath

Which of these heating methods makes it easier to control the temperature?

• Bunsen burner

• electric water bath

Which of these heating methods is associated with a risk of fire when using ethanol?

• Bunsen burner

• electric water bath

Select ALL safety precautions which should be implemented during this experiment.

• turn off Bunsen burner

• wear gloves

• wear goggles

• use methanol instead of ethanol