Dna can make exact copies of itself through replication because the nitrogen bases always pair

*What does replication mean?

Replication means to make an exact copy of itself. Like clones, or identical twins.

*Why would a cell need to replicate (make copies) of its DNA?

Our cells are always dividing and making new cells. Replication occurs before a cell divides so that each new cell will have the exact DNA as the original (parent) cells. Replication ALWAYS occurs in the nucleus of the cell.

Because of DNA's structure it can be copied or replicated. Each strand of the DNA double helix has all the information needed to reconstruct the other half by base pairing. Adenine will bond with thymine and guanine will bond with cytosine.

In Eukaryotes, DNA replication occurs at hundreds of places in both directions at the same time. It has been found to only take 3 minutes for a strand of DNA to be copied.

Replication is also very accurate. 1 error per 10,000 paired nucleotides. The cell has enzymes that proofread DNA and repairs errors as it builds the new strands of DNA during replication.

GOAL OF DNA REPLICATION:

Parent (original) DNA will separate at the hydrogen bonds where the nitrogen bases are attached into 2 single strands. Imagine taking a ladder and sawing it down the middle through all the steps.

Those half strands will make templates for the new strands to be made.

Now the original nitrogen bases no longer have their pair next to them.

New nitrogen bases will come in and fill the spots following base pairing rules (A-T, G-C)

2 (two) new strands of DNA will be created identical to the original.

Each of the new strands will have HALF of the ORIGINAL, and HALF brand NEW.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation