Understanding PCR and Gel Electrophoresis

What is the primary purpose of using PCR in forensic analysis?

• To create new DNA sequences

• To change the genetic code

• To duplicate DNA for crossmatching

• To destroy unwanted DNA

During the PCR process, what is the role of the denaturation step?

• To cool the DNA

• To split the DNA strands

• To add nucleotides

• To attach primers

What is the function of Tac polymerase in PCR?

• To add nucleotides to DNA strands

• To cool the DNA

• To attach primers

• To break hydrogen bonds

What does gel electrophoresis achieve in DNA analysis?

• It separates DNA fragments by size

• It duplicates DNA

• It destroys DNA

• It changes DNA sequences

How do restriction enzymes assist in DNA analysis?

• By changing DNA sequences

• By cutting DNA at specific sequences

• By duplicating DNA

• By tagging DNA with radioactive markers

What is the purpose of using a second restriction enzyme in DNA analysis?

• To change the DNA sequence

• To cut DNA at the same sites

• To ensure different cutting sites

• To duplicate DNA

What is the role of radioactive tagging in gel electrophoresis?

• To destroy DNA

• To change DNA sequences

• To mark specific DNA fragments

• To duplicate DNA

How can scientists differentiate between DNA fragments of the same length?

• By using radioactive tagging

• By duplicating the DNA

• By using more restriction enzymes

• By changing the DNA sequence

What happens to DNA fragments when a gel electrophoresis plate is turned on?

• They duplicate

• They move towards the negative end

• They move towards the positive end

• They remain stationary

Why might two DNA samples with the same fragment lengths not be from the same individual?

• They have been duplicated

• They are from the same person

• They have the same sequence

• They have different radioactive tags