Question

Define and briefly explain recombination repair.

A) Recombination repair is the correction of DNA damage through homologous recombination.
B) Recombination repair is a process that exclusively occurs in somatic cells.
C) Recombination repair involves the excision of damaged DNA segments.
D) Recombination repair is synonymous with base excision repair.

Answer 1

Recombination repair refers to a DNA repair mechanism that utilizes homologous sequences to correct single-stranded and double-stranded DNA breaks. It is a highly conserved process across species and is distinct from base excision repair, being essential for maintaining genetic diversity and the accurate repair of DNA without deletions.

Step-by-step explanation:

Recombination repair is a type of DNA repair that involves the use of homologous sequences to correct damage in DNA. This process can fix both single-stranded and double-stranded breaks in DNA. When a replication fork encounters a single-stranded break, recombination repair can reestablish it using homologous DNA as a template. In the case of double-stranded breaks, homologous recombination repair mechanisms utilize a number of enzymes and proteins to carry out the repair.

Contrary to option B, recombination repair is not exclusive to somatic cells; it also occurs during meiosis in germ cells. Recombination repair is an essential and conserved mechanism in all species and is different from base excision repair, making option D incorrect. This repair mechanism is crucial for the survival of species as it maintains genetic diversity and ensures the accurate repair of DNA without deletions.

• MRX, MRN: Proteins that bind at double-stranded breaks and recruit other factors.
• Sae2: An endonuclease that becomes active when phosphorylated.
• Sgs1: A helicase that participates in the homologous recombination repair process.