Can someone Help me 8 What mechanisms cells use to repair t

Can someone Help me !

8. What mechanisms cells use to repair the double strand breaks (DSBs) induced by

CRISPR/Cas9? Which of these two methods allow cells to correct a single base mutation in a

gene?

9. Why did Hershey and Chase use radioactive phosphorus and sulfur to perform their

experiment with T2 phage to demonstrate that the DNA is the genetic material?

6. You combined DNA of heat-killed cells of smooth (S) strain of Streptococcus pneumoniae

with live rough (R) strain cells of Streptococcus pneumonia in a test tube and left it for a few

hours. You then spread this mixture on a plate. What type of bacterial colonies would you

expect to see and why?

Solution

9. They used P32 because P is present in DNA not in protein/amino acids of T2 phage and S35 to label protein of T2 phage because S normally present in amino acids but not in DNA.

6. If S(smooth heat killed) strain which is virulent mixed with R(live) strain which is non virulent then genetic material get transferred from S strain to R strain and all strain will become virulent which grow on the plate.