6.3 Lesson 3: DNA Replication
- DNA replication is the process which enables the transfer of genetic information from one cell to another during cell division.
- Replication is the exact self-duplication of genetic information.
- DNA replication occurs in the following way: - a) when a cell copies a DNA molecule, each strand serves as a template for ordering nucleotides into a new complimentary strand. - b) the two strands of the DNA molecule in the chromosome uncoil and separate by ‘unzipping’ between the pairs of nitrogenous bases. - c) nucleotides floating freely in the cytoplasm, are attracted to the unzipped portion of the DNA molecule. - d) when all the bonding sites are filled with free nucleotides, two identical DNA molecules result.
- On completion, the DNA re-coils around an assortment of proteins to, again, become a chromosome.
- Both strands are replicated simultaneously.
- Each DNA strand is replicated in sequence.
- Small areas of the DNA strands are unzipped and replicated.
- Once one area is completed, the unzipping and replication continue further up the length of the DNA strands.
