Look at the following statement. What one word completes the second gap? Substances move by active transport from an area where they are __________ concentrated to an area where they are __________ concentrated.

The spontaneous movement of a substance from an area where it is more concentrated to an area where it is less concentrated is called ______.Multiple choice question.active transportdiffusionionizationendocytosis

What is the missing word? __________ substances can move into or out of cells by diffusion.

This process works because different dye particles dissolve and travel at different __________ . What word completes the gap?

Simple diffusion is the movement of molecules from areas of ______ concentration to areas of ______ concentration.Multiple choice question.lower; lowerhigher; lowerhigher; higherlower; higher

The molecule that diffuses down a concentration gradient moves from an area of ____concentration into an area of _____concentration.a.high, low                                      b.low, highc.passive, active