1.
What is the “central dogma” of molecular biology?
2.
Define “transformation” as described by Griffith.
3.
Describe Griffith’s early DNA experiment.
4.
Describe Avery, McCarty, and MacLeod’s experiment. What were their results?
5.
Summarize the experiments performed by Alfred Hershey and Martha Chase which proved that DNA is the genetic material in the bacteriophage known as T2.
6.
What information did Erwin Chargaff’s research show about the nitrogenous bases of
DNA?
7.
Distinguish between purines and pyrimidines. How do they pair with one another in DNA?
Why?
8.
Describe the semiconservative model of DNA replication proposed by Watson and Crick.
9.
What is meant by “antiparallel”?
10.
Draw the nucleotide below. Circle and label the 5’ end and the 3’ end of the molecule.
11.
What is the source of energy that drives the polymerization of DNA? Name all four of these molecules and add the abbreviations.
12.
In what “direction” does DNA synthesis occur? Why?
13.
Distinguish between the leading and lagging strands in DNA replication.

14.
Make an enzyme table:
1.
2.
3.
4.
5.
6.
7.
15.
Draw and label a simple diagram (3 parts) showing nucleotide structure.
16.
Draw 2 nucleotides bonded together. Use an arrow to point out the COVALENT bond and specify the specific name of that bond.
17.
Draw and study the following diagram showing the synthesis of DNA and then answer the questions that follow.
a) On the model above, draw with a continuous arrow where and in which direction the continuous strand of DNA would be synthesized. What is the name of this strand? b) Label the 5’ and 3’ ends on the arrow you drew in part a. c) On the model above, draw with discontinuous arrows where and in which direction the discontinuous sections of DNA would be synthesized. What is the name of this discontinuous strand? What are the names of these sections? d) Label the 5’ and 3’ ends on each of the arrows you drew in part c.

18.
Label the following structure of DNA using
the list below: (you can either draw or print)
 nucleotide
 cytosine
 guanine
 adenine
 thymine
 purine base
 pyrimidine base
 5’ end of chain
 sugar-phosphate backbone
 3’ end of chain
 hydrogen bonds
 deoxyribose
 phosphate group
19.
Summarize the evidence Watson and Crick used to deduce the double helix structure of
DNA. (remember their calculations)
20.
What is the difference between a replication bubble and a replication fork?
21.
What does dNTP stand for? Name the four dNTP’s involved in DNA replication.
22.
What are the 3 parts of a dNTP’s?
23.
DNA Replication Puzzle! This is optional! If you need a little more help, cut out these pieces and put them in order. If you want to check the key, put the numbers in the correct order and check with me during class.

1
As the excited
Biology student was running to class, eager to take
2
The enzyme Primase makes/attaches notes, he/she fell and skinned their knee. In order to make new cells to replace those lost to the concrete,
DNA must be replicated in the Sphase of
Interphase.
RNA nucleotide primers which will allow the addition of DNA nucleotides to the exposed
DNA strands.
5
DNA
Polymerase I must remove the RNA nucleotides and replace them with
DNA nucleotides.
Hydrogen bonds are made between the bases.
9
The lagging strand forms in segments called Okazaki fragments. DNA
Polymerase III will continue to build the fragments until it reaches another primer…it then falls off.
6
We now have two identical DNA strands. Each one has one original
DNA strand and one newly synthesized
DNA strand (this is called semiconservative replication)!
10
The enzyme DNA ligase bonds seals all gaps
(phosphodiester bonds)
**What does nuclease do?
3
Nuclease cuts out any mistakes or mismatches allowing
DNA polymerase
III to put on the correct base and ligase seals the repair
7
DNA elongation can now begin; leading
DNA strands will elongate toward the replication fork and lagging DNA strands will elongate away from the replication fork.
11
DNA polymerase
III adds a DNA nucleotide to the 3’ end of the RNA primers following complementary base pairing rules.
The leading strand is elongated continuously while….
4
The enzyme helicase attaches to specific regions of DNA called
Origins of
Replication and unwinds the DNA by breaking the hydrogen bonds between DNA base-pairs.
8
Single-stranded binding proteins hold the two DNA strands straight and apart.
12
With the S-phase of Interphase complete, G
2
of the Cell Cycle will commence followed by
Mitosis; the excited Biology student will now gain new skin cells!!