Question

which of the following best describes the primary role of the cell membrane in both active and passive transport? to store genetic information related to transport mechanisms. to control which substances enter and exit the cell. to synthesize proteins needed for transport. to produce energy for the cell. the sodium - potassium pump in nerve cells moves sodium ions out of the cell and potassium ions into the cell, both against their concentration gradients. this process requires: passive transport. atp. osmosis. facilitated diffusion.

Explanation:

1. The cell - membrane is a selectively permeable barrier. Its main function in both active and passive transport is to control the movement of substances in and out of the cell. Genetic information is stored in DNA in the nucleus, protein synthesis occurs in ribosomes, and energy production is mainly in mitochondria.
2. The sodium - potassium pump moves ions against their concentration gradients. This is an active - transport process which requires energy in the form of ATP. Passive transport (including osmosis and facilitated diffusion) moves substances along their concentration gradients and does not require energy input.

Answer:

1. To control which substances enter and exit the cell.
2. ATP.