Biology
Quiz Topics: DNA Structure & Replication

Be able to describe the work and contributions of each of the following to our knowledge and understanding of
DNA – What did they do? What did they conclude?

o
Frederick Griffith
o
Oswald Avery
o
Alfred Hershey & Martha Chase

Viral structure

Radioactive tags and why they were used
o
Erwin Chargaff
o
Rosalind Franklin & Maurice Wilkins
o
James Watson & Francis Crick
o
Meselson & Stahl
Structure of DNA
o
What is the monomer?
o
What three things make up this monomer?
o
Double-helix or “twisted ladder” shape

What two molecules make up the sides of this ladder? What type of bond holds them together?

What molecules make up the steps or rungs of the ladder? What type of bond holds them
together?
o
Base-pairing rule – Which bases pair together? How many bonds hold each pair together? Be able to
give the complementary strand (ex. for ATTCCG, complementary strand is TAAGGC) and be able to
determine % of each bases given info for one base. (%T = 15% then % A = 15%, %G = 35% and %C = 35%)
o
Purine v. Pyrimidine bases – What is the difference? Identify the two examples of each.
o
What does it mean to say the two strands of DNA run antiparallel?
o
Distinguish between the 5’ and 3’ end
o
You will need to identify the following on a diagram of DNA: nucleotide, deoxyribose, phosphate,
adenine, thymine, guanine, cytosine, 5’ end and 3’ end

DNA replication
o
Why does DNA need to be replicated? When in the cell cycle does this event occur?
o
Role of the enzymes involved: helicase, restriction enzymes, DNA polymerase & ligase
o
What does it mean to say the original DNA strands serve as a template?
o
What is a replication fork?
o
Distinguish between the leading and lagging strands of replication
o
Why is it a semi-conservative process? How does base-pairing relate? What does the semi-conservative
nature of the process allow to happen?
NOTE: This is meant to guide your studying only. Anything covered in class, the notes or textbook is fair game for the quiz.