The repair of double-strand breaks in DNA via homologous and nonhomologous mechanisms to reform a continuous DNA helix.

Any process in which an organism or cell protects itself from ultraviolet radiation (UV), which may also result in resistance to repeated exposure to UV.

Any process that decreases the rate, frequency or extent of strand invasion. Strand invasion is the process in which the nucleoprotein complex (composed of the broken single-strand DNA and the recombinase) searches and identifies a region of homology in intact duplex DNA. The broken single-strand DNA displaces the like strand and forms Watson-Crick base pairs with its complement, forming a duplex in which each strand is from one of the two recombining DNA molecules.

The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, most prokaryotic cells and some protozoan parasites, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan; in protozoan parasites such as Giardia species, it's made of carbohydrates and proteins.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

A protein complex that possesses DNA helicase activity.