Scientists use this word for any part of a cell enclosed by a membrane

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.

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion