Forensic DNA

Which suspect's DNA matches that of the Crime Scene (CS)? Must look at picture!

• Suspect 1

• Suspect 2

• Suspect 3

• Suspect 4

Tags

NGSS.HS-LS3-1

Gum is found at the scene of a robbery - it may have been left by the thief! A DNA Fingerprint is made of the saliva on the gum, along with the three suspects. None of the suspects' DNA Fingerprints match the gum. Which of the following is TRUE about this case?

• DNA Fingerprints sometimes change, so we can not rule out any suspects yet

• The DNA Fingerprinting must have been done wrong

• Since the DNA Fingerprint did not match any suspect, none of these suspects is the thief

• Since the DNA Fingerprint did not match any suspect, none of these suspects left the gum

Study the DNA Fingerprint shown here. Who committed the crime?

• Suspect 1

• Suspect 2

• Victim

• None of the above. Everyone is innocent here

What is the first step to making a DNA Fingerprint?

• Make millions of copies of the DNA

• Cut the DNA into different sized pieces

• Separate the DNA pieces by size

• Compare DNA fingerprints, find a match

What is the second step to making a DNA Fingerprint?

• Make millions of copies of the DNA

• Cut the DNA into different sized pieces

• Separate the DNA pieces by size

• Compare DNA fingerprints, find a match

T or F: The second step to making a DNA Fingerprint is to cut the DNA into different sized pieces.

• True

• False

What is the third step to making a DNA Fingerprint?

• Make millions of copies of the DNA

• Cut the DNA into different sized pieces

• Separate the DNA pieces by size

• Compare DNA fingerprints, find a match

T or F: Restriction Enzyme is like scissors that cuts DNA at a particular sequence

• True

• False

Three tools are used to make a DNA fingerprint - which one is like a biological copy machine, making thousands of copies of each piece of DNA?

• PCR Machine

• Restriction Enzyme

• DNA Ligase

• Gel Electrophoresis machine

During the Cut step, why would your DNA be cut into different sized pieces than your neighbor's DNA?

• A different restriction enzyme is used

• Your DNA has a different sequence than your neighbor's

• Restriction enzymes cut randomly, no two Fingerprints are ever the same

• DNA samples are heated to different temperatures, causing DNA to break into different sized pieces