The nitrogen bases always pair up in a specific pattern.
Adenine(A) pairs up with Thymine(T)
Guanine(G) pairs up with Cytosine(C)
A G C T A C G C A one side T C G A T G C G T other side
All organisms have the same type of nucleotides. The nucleotide arrangement provides for all the different types Ex- A mouse and a rosebush have the same nucleotides. However, they are different because their nucleotides are in different orders. *This sequence of nucleotides forms the genetic information(code) of an organism.
Replication of DNA During meiosis and mitosis a copy of DNA must be made so that when the new cells are formed, they each get an exact copy of the genetic information. This DNA copy is made through a process known as replication.
Steps of Replication During replication, each strand serves as a pattern to make new DNA molecule.
First step: DNA (H bonds are broken) unzips into 2 strands
Second step: free nucleotides join onto “unzipped” strands to form 2 new strands of DNA
2 complete strands will result, these will be exactly alike
Figure 12–11 DNA Replication Section 12-2 Growth Growth Replication fork DNA polymerase New strand Original strand DNA polymerase Nitrogenous bases Replication fork Original strand New strand