Critical Thinking
4. Tube A and Tube B are included in this experiment as controls. Explain
the role that each control plays in this experiment.
● Tube A: Type your answer here.
● Tube B: Type your answer here.
2. Assume you set up a tube that contained a gRNA and the DNA sample,
but no Cas9 nuclease. Would you expect the DNA sample to be cut?
Justify your response.
Type your answer here.
3. Compare the results from the four different reactions. Which tube(s) best
demonstrate(s) that Cas9 will only target and cut DNA in the presence of
a guide RNA? Justify your answer.
Type your answer here.
4. Compare the results from the four different reactions. Which tube(s) best
demonstrate(s) the function of the gRNAs to guide the Cas9 nuclease to
target a specific DNA sequence? Justify your answer.
Type your answer here.
5. This lab demonstrates that the same Cas9 nuclease can be used to cut a
DNA sample at two different locations, just by changing the gRNA used.
In your own words, describe how this makes the CRISPR/Cas9 system
useful as a genome editing tool.
Type your answer here.
6. In the lab portion of this activity, there were billions of DNA molecules in
each tube. Each DNA strand was an identical 3,142 base pairs long and
contained the correct target sequence for the gRNA. Compare this to the
DNA in a living cell. How might you expect targeting in a cell to be
different from what you did in this experiment?
Type your answer here.
Chopped! Using CRISPR/Cas9 to cut DNA Lab. Student E-worksheet™.
Release: September 2023. © 2023 by miniPCR bio
TM
