1. DNA Replication

2. Why do cells need to divide?
Replace old cells
Growth
Repair cuts/ wounds
Reproduction

3. When cells divide, what happens to DNA?
Each cell needs a complete set of 46 chromosomes.
Cells must replicate, or make an exact copy of the DNA to put in new cells.
DNA Replication
1 DNA
2 DNA

4. Steps of Replication:
1: DNA double helix unwinds.

5. Steps of Replication:
2: Hydrogen bonds break and strands begin to unzip.

6. Steps of Replication:
3: Free nucleotides pair up with nucleotides on parent strand to form a complementary strand.

7. What is produced in replication?
At the end of replication, two IDENTICAL strands of DNA have been formed!

8. DNA replication is semi-conservative
Each new strand pairs up with an old strand two produce two DNA molecules each containing one parent (old) and one daughter (new) strand.

9. What happens to the extra set of DNA?
After DNA is replicated, a cell splits to form two cells that each get one copy of the DNA!