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.
Salinity is important in coastal waterways for the following reasons: 1  Salinity is a dynamic indicator of the nature of the exchange system. 2  The salinity of the water within the estuary tells us how much fresh water has mixed with sea water.