Replication

Semiconservative replication

Each daughter duplex contains one parental strand and one daughter strand.

Conservative replication

One daughter duplex consists of both parental strands and the other consists of both daughter strands.

Dispersive replication

Each daughter duplex contains interspersed parental and daughter segments.

Meselson and Stahl experiment

An experiment that demonstrated that DNA replication is semiconservative by using density gradient ultracentrifugation.

DNA polymerase

An enzyme that synthesizes DNA molecules by adding nucleotides to a growing DNA strand.

Okazaki fragments

Short segments of DNA synthesized on the lagging strand during DNA replication.

Leading strand

The DNA strand that is synthesized continuously in the same direction as the replication fork progresses.

Lagging strand

The DNA strand that is synthesized discontinuously, opposite to the direction of the replication fork, forming Okazaki fragments.

Telomeres

Special, non-coding DNA repeat sequences at the ends of linear chromosomes that protect the chromosome ends.

PCR (Polymerase Chain Reaction)

A technique used to amplify specific DNA sequences exponentially using thermal cycling.

End replication problem

The issue that arises in linear DNA replication where the terminal primer is removed, potentially leading to the loss of DNA.

Telomerase

An enzyme that adds repetitive nucleotide sequences to the ends of telomeres, counteracting the end replication problem.

DNA replication fork

The Y-shaped region where the DNA double helix is unwound for replication to occur.

dNTPs (Deoxynucleoside triphosphates)

The building blocks required for DNA synthesis during replication.

Primase

An enzyme that synthesizes RNA primers needed for starting DNA synthesis.