Biological Skills DNA & Extraction Methods

What is the purpose of a buffer system in electrophoresis?

• Alternate the current

• Carry the current, maintain a stable pH for the separation of molecules and protect the sample

• disrupt the contaminants

• stop the migration process

How can DNA fragments be separated using gel electrophoresis ?

• DNA carries a negative charge and large fragments are pulled more strongly than small fragments towards the positive electrode

• DNA carries a negative charge and small fragments are able to travel more quickly than large towards the positive electrode

• DNA carries a positive charge and large fragments are pulled more strongly than small fragments towards the negative electrode

• DNA carries a positive charge and small fragments are able to travel more quickly than large towards the negative electrode

Where would you find DNA, the genetic material, in an animal cell?

• In the centriole

• Only in the mitochondria

• In the mitochondria and the nucleus

• In the cytoplasm

What is the first step in isolating DNA?

• Generating genomic DNA fragments with restriction endonucleases

• Introducing recombinant DNA into an organism by any means

• Overexpressing proteins in E. coli

• Lysing the cells in the sample

What is the role of ethanol in DNA extraction?

• To break down cell walls

• To precipitate DNA from the solution

• To neutralize the pH

• To increase the solubility of the DNA

Which of the following statements accurately describes the role of centrifugation in DNA extraction?

• It lyses the cells to release DNA.

• It selectively precipitates DNA from the solution.

• It separates DNA fragments based on size.

• It separates heavier cellular components from the DNA suspension.

Why do we use salt for this lab?

• to dissolve the lipids in the nuclear envelope

• We don't use salt.

•  removes protein that is chemically joined to DNA

• DNA will precipitate (form) in less dense ethanol layer

Which of the following is a beaker?

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Which of the following is a test tube?

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Which of the following is a pipette?

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