Which form of dna is classified as a left-handed double helix?
a. a-dna
b. b-dna
c. z-dna
d. cruciform dna
e. hairpin dna?

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above

The model illustrates a process by which a substance is taken up by a cell. which statements describe the process? a. the model shows the process of endocytosis. b. the process shown in the model requires energy from the cell. c. the cell membrane in the model remains intact throughout the process. d. the model shows the process of facilitated diffusion.

All cells need water to survive. in order to maintain the necessary amounts, water can flow across the cell membrane from areas of higher concentration to areas of lower concentration. what is this flow of water called? a) active transport b) allocation c) diffusion d) osmosis