The process of restoring DNA after damage. Genomes are subject to damage by chemical and physical agents in the environment (e.g. UV and ionizing radiations, chemical mutagens, fungal and bacterial toxins, etc.) and by free radicals or alkylating agents endogenously generated in metabolism. DNA is also damaged because of errors during its replication. A variety of different DNA repair pathways have been reported that include direct reversal, base excision repair, nucleotide excision repair, photoreactivation, bypass, double-strand break repair pathway, and mismatch repair pathway.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating damage to its DNA from environmental insults or errors during metabolism.

The modification of a histone by the addition of an acetyl group.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a reactive oxygen species stimulus. Reactive oxygen species include singlet oxygen, superoxide, and oxygen free radicals.

A reversible switch of a cell from one cell type or form to another, at a frequency above the expected frequency for somatic mutations. Phenotypic switching involves changes in cell morphology and altered gene expression patterns. For example, Candida albicans switches from white cells to opaque cells for sexual mating. Phenotypic switching also occurs in multicellular organisms; smooth muscle cells (SMCs) exhibit phenotypic transitions to allow rapid adaption to fluctuating environmental cues.

Any process that stops, prevents, or reduces the frequency, rate or extent of pseudohyphal growth.

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.