2.  Tell me about the discovery made by Watson and Crick.  These scientists made even more important discoveries.

3.  What observations did you make about DNA during yesterday’s activity?  What about Purines and Pyrimidines?

4.  When they figured out that DNA has a double helix structure, they also made a connection with how the nucleotide base pairs match up.  Look at these two base pairs  Is Adenine a purine or pyrimidine?  What about Thymine?

5.  So, Purines pair with Pyrimidines!  Watson and Crick realized this when they came up with the double helix structure. This was because of the hydrogen bonds between the two matched up perfectly to create the double helix structure.

7.  Who was Gregor Mendel?  Who was Frederick Griffith?  Who was Oswald Avery?  Who were Hershey and Chase?  Who was Chargaff?  Who was Franklin?  Who were Watson and Crick?

8.  What makes up the backbone of DNA?  What are the 4 nucleotides?  What is Chargaff’s Rule?  What is the difference between a purine and a pyrimidine?  What bond holds together the two strands of DNA?