What is DNA replication?

I don't know, but Wikipedia does.

http://en.wikipedia.org/wiki/DNA_replication

DNA replication is the process by which a cell makes an exact copy or replica of its DNA. It is a fundamental process that occurs in all living organisms and is essential for the transmission of genetic information from one generation to the next.

To understand DNA replication, it's important to know that DNA is a double-stranded molecule made up of nucleotides. Each nucleotide consists of a sugar (deoxyribose), a phosphate group, and one of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), or guanine (G). The two strands of DNA are held together by hydrogen bonds between complementary base pairs: A always pairs with T, and C always pairs with G.

The process of DNA replication involves several steps:

1. Initiation: The DNA double helix unwinds and separates, creating a replication fork. This is achieved by enzymes called helicases, which break the hydrogen bonds between the base pairs. Single-strand binding proteins keep the two DNA strands apart and prevent them from rejoining.

2. Primer synthesis: Primers, short RNA sequences, are synthesized by another enzyme called primase. These primers provide a starting point for DNA synthesis.

3. Elongation: DNA polymerase enzymes attach to the primers and start adding nucleotides to the growing DNA strands. DNA polymerase can only add nucleotides in the 5'-to-3' direction, so it can only synthesize one new DNA strand (leading strand) continuously. The other strand (lagging strand) is synthesized in short segments called Okazaki fragments, which are later joined together.

4. Termination: Once the entire DNA molecule has been replicated, special proteins called terminators help release the DNA polymerase enzymes, and the newly formed DNA strands are checked for errors.

Overall, DNA replication is a highly regulated and accurate process that ensures the faithful transmission of genetic information. By understanding the steps involved, scientists have gained insight into how DNA replication occurs and how mutations can arise.