The question is on the attachment

It controls activities

Explanation:

X is the nucleus of the cell which is sometimes know as the 'brain' of the cell because it controls activities. It contains DNA that is needed to conduct most of the cell's functions.

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.

not sure if this what   you'r looking for would be percent composition