DNA Replication Worksheet

 

The Big Idea!

The structure of DNA, the molecule of heredity, enables the molecule to copy itself.

 

Concepts

 

PART A

Complete the following strand of DNA by placing the letter of the correct nitrogenous base on the line provided

 

5

 

C

 

C

 

A

 

G

 

T

 

A

 

G

 

T

 

T

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

If the DNA molecule above were the parent strand of DNA, when the strands are split for replication, which strand would be the template for the leading strand? Why?

 

 

 

 

PART B

1. Why does DNA need to replicate?

 

 

 

2. How do base-pairing rules make DNA replication possible?

 

 

3. What did the Meselson-Stahl experiment show?

 

 

 

4. What mode(s) of replication did Watson and Crick think DNA used? Were they right? How do you know?

 

 

 

 

5. Explain three main steps in the process of DNA replication. Name the enzymes that go with each step (HINT: There are 4 main enzymes, 2 of them go with the second step).

a.

 

 

 

b.

 

 

 

c.

 

 

 

 

6. What are Okazaki fragments? Why are they needed?

 

 

 

 

 

7. Draw a picture of DNA replication. Label the direction each strand is going, the enzymes involved with each step, the leading and lagging strands, and Okazaki fragments. (You do not have to show base-pairing in your picture).