What is the difference between osmosis & diffusion? What are the TWO types of active transport?

What are the TWO types of passive transport?

Substances can only move into or out of a cell if the cell membrane is .

In diffusion, particles move from an area of higher concentration to one of lower concentration until equilibrium is reached. In osmosis, a semipermeable membrane is present, so only the solvent molecules are free to move to equalize concentration.

Simple Diffusion and osmosis are both forms of passive transport and require none of the cell's ATP energy.

Active Transport.

Those proteins do much of the work in active transport. They are positioned to cross the membrane so one part is on the inside of the cell and one part is on the outside. Only when they cross the bilayer are they able to move molecules and ions in and out of the cell.

hope I help! sorry if Im wrong.

Im not sure in the last question.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.