In biology, a mutation is a permanent change of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements.
Salinity is the saltiness or dissolved salt content of a body of water (see also soil salinity).onceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sodium bicarbonate which dissolve into ions.
Absolute (or ideal) salinity is the mass fraction of salts in seawater [17]. In practical terms, salinity is expressed as PSU (practical salinity units) which are based on water temperature and conductivity measurements [17].