Question

(b.4b) a person with swollen gums rinses his mouth with warm salt water, and the swelling decreases. which has occurred? the swollen gums have absorbed the saltwater solution. the salt in the solution has moved against the concentration gradient. the saltwater solution lowers the temperature of the water in the gums. the water in the gums has moved from a high to a low concentration of water.

Explanation:

This is an example of osmosis. Swollen gums have a higher water - content area compared to the salt - water solution. Water moves from an area of high water concentration (in the gums) to an area of low water concentration (the salt - water solution) to equalize the concentration, reducing the swelling. Salt does not move against the concentration gradient in this simple rinsing scenario, and the salt - water solution doesn't lower the temperature of the water in the gums in a way that causes swelling reduction. Also, the gums don't absorb the salt - water solution in the relevant sense for this swelling reduction.

Answer:

The water in the gums has moved from a high to a low concentration of water.