Chapter 5: DNA Replication, Repair, and Recombination

Mobile genetic elements

include transposons, which move within a single cell (and its descendants), plus those viruses whose genomes can integrate into the genomes of their host cells.

DNA Replication

The biological process of producing two identical replicas of DNA from the original DNA molecule.

Mutation

A permanent change in the DNA that occurs when the cell's DNA maintenance fails.

Low mutation rates

Mutation rates that are necessary for life, as an increase in mutation frequency can lead to the incidence of cancer.

DNA polymerase

Enzyme responsible for the formation of new DNA chains during DNA replication.

Watson and Crick

Scientists who proposed the double helical structure for DNA and the semi-conservative DNA replication scheme.

Semi-conservative DNA replication

The proposed scheme for DNA replication where the two strands of DNA separate and act as a template for the synthesis of new complementary strands.

Unwinding of the DNA

The process of separating the two strands of DNA during DNA replication.

Helicase

Enzyme responsible for unwinding the DNA during DNA replication.

DNA Repair

The set of processes that corrects spontaneous changes in DNA to maintain its integrity.

Homologous recombination

The exchange of DNA strands between homologous chromosomes during genetic recombination.

DNA Base-pairing

The process of re-forming the DNA double helix from its separated single strands during homologous recombination.

Transposition

The movement of genetic elements within a genome by either retrotransposition or DNA transposition.

Conservative site-specific recombination

The rearrangement or exchange of DNA segments between specific target sites in the genome without movement to a new genomic location.

DNA Repair Mechanisms

The various processes involved in correcting errors and damages in DNA sequences, including mismatch repair, base excision repair, nucleotide excision repair, double-strand break repair, and homologous recombination.

Epigenetic Modifications

Chemical changes to DNA or associated proteins that affect gene expression without altering the underlying DNA sequence.