Which of the following molecular movements is due to diffusion or osmosis? a) the sodium-potassium pump pumps three sodium ions out of a neuron for every two potassium ions it pumps in. b) when a plant cell is placed in concentrated salt water, water moves out of the cell. c)cells of the pancreas secrete insulin into the bloodstream.

The correct answer is  b) When a plant cell is placed in concentrated salt water, water moves out of the cell.

Explanation:

Osmosis is the movement of solvent molecules from an area of less concentration of solute to high concentration of solute to equalize the concentration of both the side of the cell.

So water will move outside the cell when any cell will be placed in a concentrated salt water because the concentration of solute is high in salt water and low inside the cell.

Therefore when a plant cell is placed in salt water the osmosis of water takes place from inside to outside the cell. So the right answer is b.

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion