Question

all of the following are characteristics of passive transport except: substances move down a concentration gradient. substances move downhill, from high to low concentration, and require energy expenditure. substances move from high to low concentration. no energy expenditure is required.

Explanation:

Passive transport is the movement of substances from an area of high concentration to an area of low concentration (down - concentration gradient) without the expenditure of energy. The statement that substances moving downhill from high to low concentration and require energy expenditure is incorrect for passive transport as it is a characteristic of active transport.

Answer:

Substances move downhill, from high to low concentration, and require energy expenditure.