Final answer:
When a hypertonic Paramecium is moved to solutions of decreasing osmolarity, the rate of its contractile vacuole contractions increases to pump out excess water and prevent cell lysis.
Step-by-step explanation:
If a Paramecium is hypertonic to its environment, and it is moved to solutions of decreasing osmolarity, the rate at which the Paramecium's contractile vacuole contracts would increase. This increase is because more water would diffuse into the Paramecium, and the contractile vacuole must work harder to pump out this excess water to prevent the cell from bursting. A hypertonic solution is one where the concentration of solutes is higher inside the Paramecium than in the surrounding solution, leading to a net movement of water into the cell.
The contractile vacuole is a cellular structure that helps maintain osmotic balance by expelling excess water. In hypertonic conditions, water moves out of the cell, and the cell can become dehydrated through a process called plasmolysis, where the cell membrane shrinks and detaches from the cell wall.
Paramecia utilize their contractile vacuoles to excrete waste and manage water intake in various osmotic conditions. In a hypotonic environment, higher rates of contraction are required to keep the cell from bursting, as visualized using microscopy and monitored during experiments with Paramecia in different salt solutions.