Paramecium, shown here, possess that counteract the effects of osmosis.

The correct answer is: contractile vacuoles.

Paramecium is simple unicellular ciliate that lives in the water environments. It is often used as model organism in laboratory experiments because of its ability to easy conjugate and divide.

Osmoregulation of the paramecium is regulated by contractile vacuoles (one or more within the cell). Contractile vacuoles expel water from the cell in order to compensate for fluid absorbed by osmosis from its water surroundings.

cramming before a final is bad because it makes a student's stress level higher. students who embrace cramming to get through a final exam week find themselves struggling to perform consistently, once the brain adjusts to prolonged sleep deprivation.

weathering is the answer.