What is responsible for DNA replication?
One of the key molecules in DNA replication is the enzyme DNA polymerase. DNA polymerases are responsible for synthesizing DNA: they add nucleotides one by one to the growing DNA chain, incorporating only those that are complementary to the template.
What are mistakes in DNA replication called?
Mutations. Diagram of a DNA molecule looking like a twisted ladder. When there is a mistake in the copying of the genetic message that is permanent, a mutation has occurred. UV light can cause mutations, as the DNA molecules are good absorbers of UV.
What are two ways that DNA replication is checked for errors?
Proofreading, which corrects errors during DNA replication. Mismatch repair, which fixes mispaired bases right after DNA replication. DNA damage repair pathways, which detect and correct damage throughout the cell cycle.
What happens if DNA replication does not occur?
The cell’s DNA is copied during the synthesis phase. If the cell has not properly copied its chromosomes, an enzyme called cyclin dependent kinase, or CDK, will not activate the cyclin, and the cell cycle will not proceed to the next phase. The cell will undergo cell death.
What causes a mutated gene?
These changes can be caused by environmental factors such as ultraviolet radiation from the sun, or can occur if an error is made as DNA copies itself during cell division. Acquired mutations in somatic cells (cells other than sperm and egg cells) cannot be passed to the next generation.