Question

Which scenario below could be used to represent how a cell uses active transport to move molecules across a membrane?

A. a fish swimming upstream
B. a child riding a bike down a hill
C. wind blowing a sailboat in the ocean
D. a car driving through a mountain tunnel

Answer 1

A fish swimming upstream represents how a cell uses active transport, an energy-consuming method to move substances across a membrane against their concentration gradient.

Step-by-step explanation:

The scenario that could be used to represent how a cell uses active transport to move molecules across a membrane would be A. a fish swimming upstream. This is because active transport is the energy-requiring process of pumping molecules and ions across membranes 'uphill' - against a concentration gradient, similar to a fish using energy to swim against the current.

Other transport mechanisms, such as passive transport, do not require energy and involve substances moving down their concentration gradients. An example of active transport is the sodium-potassium pump, which critically depends on ATP to move sodium and potassium ions across the cell membrane against their respective concentration gradients.