Quiz 3

Which of the following statements about diffusion is correct? It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration It is an active process in which molecules move from a region of lower concentration to one of higher concentration It requires an expenditure of energy by the cell It requires integral (transmembrane proteins)

It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration

The beaker in the illustration contains two solutions of salt with different concentrations (A - 0.2 M, B-0.9M) The two solutions are separated by a membrane that is permeable to both salt and water. Which of the following will occur immediately? Net diffusion of water from B to A and of salt from A to B Net diffusion of water from A to B and of salt from B to A Net diffusion of water across the membrane, but not of salt Diffusion of salt across the membrane, but not of water Net diffusion of salt from B to A, but no net diffusion of water

Net diffusion of water from A to B and of salt from B to A

In plants, water moves through xylem toward the leaves because: Water potential is higher in leaves than in roots Water potential is lower in air than in roots Pressure potential is higher in leaves than in roots Solute potential is higher in leaf cells than in the xylem Solute potential in leaf xylem is lower than in root xylem

Water potential is lower in air than in roots

Assuming the stomata are open to the same degree, the rate of transpiration should __ on a rainy day compared with a sunny day because the H2O concentration gradient from the inside to the outside of the leaf would __. decline; decrease decline; increase remain the same; not change increase; decrese increase; increase

decline; decrease

When a photon hits a chlorophyll molecule in a Photosystem, __ moves forward the reaction center chlorophyll by __ an electron, resonance transfer energy, resonance transfer an electron, oxidation/reduction energy, fluorescence energy, oxidation/reduction

energy, resonance transfer

In plants, sugars move in the phloem: from source to sinks via bulk flow according to the cohesion-tension theory through dead cells all of the above are true

from source to sinks