What important role do unicellular organisms play in sustaining life on earth?

They help so that other organisms to feed off of they also have major nutrients needed for us to survive that makes its way into plants especially plants in the sea 

The patient has increasing neck swelling. the neck swelling may lead to respiratory difficulty, and rapid intervention is needed to prevent airway obstruction. the incisional pain should be treated but is not unusual after surgery. a heart rate of 112 is not unusual in a patient who has been hyperthyroid and has just arrived in the pacu from surgery. sleepiness in the immediate postoperative period is expected.

Answerions break away form the crystals and are surrounded by water;                           it is an example of a chemical change;