What characteristic makes osmosis different from diffusion?

a: osmosis occurs through a semipermeable membrane. diffusion occurs through a permeable membrane.

b: net movement in osmosis is from areas of higher concentration to areas of lower concentration. net movement in diffusion occurs from areas of higher concentration to areas of lower concentration.

c: osmosis requires facilitation by an energy-carrying molecule, such as atp. diffusion requires no additional energy to move molecules across the concentration gradient.

d: osmosis is used for gases, such as oxygen and carbon dioxide. diffusion is used for water that contains salt or sugar molecules.

Net movement in osmosis is from areas of higher water concentration to areas of lower water concentration. Net movement in diffusion occurs from areas of higher solute concentration to areas of lower solute concentration.

I took the unit test, this is the correct answer.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.