During hum canes saltwater is blown into freshwater marshes

During hum canes, saltwater is blown into freshwater marshes. Why do many of the freshwater plants and fish die? At the cellular level, what would you expect to happen if you placed a piece of raw potato into tap water, and a solution of 10% sodium chloride? Paramecium caudate lives in a hypotonic solution. Excess water is removed from the cell via structures called contractile vacuoles. Given what you know about6 vacuoles (refer to Table 6.2, p, 98) and what you know about cells able to contract, suggest the type of transport that occurs when water is moved out of paramecium.

Solution

2.2 Raw potato swells when placed in tapwater, no change in cell volume when placed in distilled water and shrinks when placed in 10% sodium chloride

Reason : If cells are placed in a solution of nonpenetration solutes having an osmolarity of 300 mOsm, they will neither swell nor shrink since the water concentrations in the intra- and extra cellular fluid are the same and the solutes cannot leave or enter. Such solutions are said to be isotonic. Solution containing less than 300 mOsm of nonpenetrating solutes, hypotonic solution, will cause the cell to swell because water will diffuse into the cell from its higher concentration in the extracellular fluid. Solution having greater than 300 mOsm of nonpenetrating solutes, hypertonic solution, will cause cells to shrink as water diffuses out of the cell into the fluid with a lower water concentration.

2.1 Thus, due to the above reason, when the freshwater plants and animals living in hypotonic medium are suddenly exposed to seawater (hypertonic medium) during hurricane, shrink and die.