Cells sometimes use passive transport to move molecules across their membranes. The rate at which a cell engages in passive transport is determined by — the amount of energy that the cell generates.

the composition of the cell membrane.

the size of the cell's chloroplasts.

the number of vacuoles that the cell contains.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

answer; the above statement is (true);

amber has allowed scientists to study dna that has been preserved over millions of years.

the wires in the toaster turning red and the toast crisping and turning brown