NAME: _____________________________________  PERIOD:___________________

 

DATE:__________________________ DATE DUE:_____________________________

 

DNA REPLICATION

MATERIALS:

Paper model of DNA

Copies of DNA nucleotides

Scissors

Glue or tape

Two pieces of construction paper

 

PROCEDURE:

1. Cut your model of DNA in half as if enzymes were “unzipping” the molecules by breaking the hydrogen bonds between the base pairs.

 

2. Tape or glue the left side of the DNA molecule to a piece of construction paper.

 

3. Tape of glue the right side of the DNA molecule to a different piece of construction paper.

 

4. Cut out the four DNA nucleotides that are complementary to the left side of the original DNA molecule.

 

5. Match the complementary nucleotides to the left-sided template (HINT: they fit like the pieces of a puzzle) to make a new molecule of DNA.  Tape or glue the nucleotides to the piece of construction paper.

 

6. Cut out the four DNA nucleotides that are complementary to the right side of the original DNA molecule.

 

7. Match the complementary nucleotides to the right-sided template to make a new identical molecule of DNA.  Tape or glue the nucleotides to the piece of construction paper.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

QUESTIONS:

 

1. What is this a picture of?   

 

 

 

2. Label the three parts of the picture above.

 

3. What is the name of the sugar in DNA?

 

 

4. How many nucleotides are in the original molecule of DNA?

 

 

5. How is each nucleotide alike?

 

 

6. How is each nucleotide different?

 

 

7. If DNA is “ladder-like”, which two parts of the nucleotide form the sides of the ladder?

 

 

8. To which of these two parts does the base attach?

 

 

9. Which part of the nucleotide forms the “rungs” of the ladder?

 

 

10. What holds the two strands of the DNA molecules together?

 

 

11. Only two combinations of base pairings are possible for DNA.  Name these two possible base pairs.

 

 

 

12. What is used to “unzip” the DNA molecule during replication?

 

 

 

13. What is true about the two new molecules of DNA formed at the end of replication?

 

 

 

14. When in the cell cycle does replication occur?

 

 

 

15. Why is it important that DNA can make exact copies of itself?