AP BIOLOGY

Detailed explanation-1: -Answer and Explanation: A cell that neither gains nor loses water when it is immersed in a solution is isotonic to its environment which means that the correct choice is C.

Detailed explanation-2: -If a cell is placed in an isotonic solution, there will be no net flow of water into or out of the cell, and the cell’s volume will remain stable. If the solute concentration outside the cell is the same as inside the cell, and the solutes cannot cross the membrane, then that solution is isotonic to the cell.

Detailed explanation-3: -An isotonic solution is any external solution that has the same solute concentration and water concentration compared to body fluids. In an isotonic solution, no net movement of water will take place.

Detailed explanation-4: -Animal cells, like red blood cells, function optimally in isotonic solutions.

Detailed explanation-5: -A cell in an isotonic solution is in equilibrium with its surroundings, meaning the solute concentrations inside and outside are the same (iso means equal in Latin). In this state there is no concentration gradient and therefore, no large movement of water in or out.