Student Exploration: Paramecium Homeostasis
Vocabulary: cell mouth, cilia, concentration, contractile vacuole, food vacuole, homeostasis, hypertonic, hypotonic, macronucleus, micronucleus, oral groove, osmosis, paramecium, solute, solution, solvent
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
The images show red blood cells (RBCs) in three different solutions.
Which image shows RBCs in normal blood plasma?
Which image shows RBCs in pure water?
Which image shows RBCs in a very salty solution?
What do you think is happening in images A and C?
A paramecium is a one-celled organism that lives in ponds and other bodies of water. One of the challenges for a paramecium is to maintain a stable size and shape.
On the Paramecium Homeostasis Gizmo™, turn on the Show labels checkbox. Try to determine the function of each of the labeled structures.
Through which two structures do you think food enters the paramecium?
Which two structures contain DNA?
Which tiny structures help the paramecium to move around?
Which structure pumps out excess water and wastes?
Maintaining a water balance
Get the Gizmo ready:
Select the User controlled setting.
Check that the Water solute concentration is 1.00%.
Introduction: Every organism needs to maintain stable internal conditions—a process known as homeostasis—in order to survive. A paramecium maintains homeostasis by responding to variations in the concentration of salt in the water in which it lives. (The concentration of a solution is equal to the amount of solute that is dissolved in a given amount of solvent.)