DNA polymerase occasionally makes errors and adds an incorre
     DNA polymerase occasionally makes errors and adds an incorrect base. A new strand of DNA is being produced, and the template strand contains a G. Based on your knowledge of the structure of DNA, why is it more likely that DNA polymerase would accidently add a T to the new strand instead of a G or an A.?  Multiple Choice  Because G normally pairs with T.  Because G normally pairs with either T or C.  Because the structure of T and G are similar as they both have a double ring.  Because the structure of T and C are similar as they both have a single ring. 
  
  Solution
G and C always pair with each other. The structure of T and C are similar
Hence there is a chance that T may be added instead of C

