Which of the following is NOT a characteristic of active transport? * A)It moves substances against a concentration gradient
B)It requires energy from the cell
C)It involves facilitated diffusion
D)It may use carrier proteins that often function as the sodium potassium pump

It involves facilitated diffusion.

Explanation:

Facilitated diffusion uses channel proteins. Channel proteins allow substances to travel through a membrane going with the gradient. Since active transport goes against the gradient, facilitated diffusion would not be a characteristic of it.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.