9. Facilitated diffusion is often used to transport Alons

B. molecules that are not soluble in lipids,

C. molecules that are too small to diffuse

across the membrane.

D. both A and B.

E all of the above.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: