During transcription, enzymes bind to a molecule of dna. then, the enzymes unwind and separate the dna's double helical strands. as the molecule unwinds, complementary nucleotides pair with one of the dna strands to form

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

then that particular organisms become extinct.