What term defines the movement of materials along a concentration gradient through protein channels?

Defend or refute the argument that the government has too large a presence in the agriculture industry.

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.

Plsss > .< compare and contrast the characteristics of flatworms rounds worms and earthworms