Which phrase provides the best definition of mass movement?
the movement of material caused by erosion
the slow flow of a glacier as it moves through the valley of a mountain
the movement of large amounts of soil and rock debris down a slope
the fast movement of a boulder rolling down a slope

the answer is:

carbon dioxide

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.

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.