when the required direction of transport is opposed to concentration levels, a cell (1) expend energy to force (2) across its membrane.

1: a. will
b. will not

2: a. ions
b. metals
c. minerals

When the required direction of transport is opposed to concentration levels, a cell will expend energy to force ions across its membrane.

Explanation:

If the concentration gradient is opposite to the direction of transport of minerals, then the cell will use energy to transport mineral ions from a lower concentration to a higher concentration. The most common process through which this happens is termed as the active transport.

The process of active transport is opposite to passive transport. In passive transport, molecules move from a higher concentration to a lower concentration.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

c

explanation: