1.What process is defined as the net movement of water molecules from a low concentration of solute to a high concentration of solute?
(a)osmosis
(b)co-transport
(c)dynamic equilibrium
(d)active transport
(e)None of the answers are correct.
2.Which of the following statements is true about what will happen to cells depending on tonicity?
(a)Turgor pressure pushes a plant cell membrane against the cell wall in hypotonic solution.
(b)Turgor pressure pushes a plant cell membrane against the cell wall in hypertonic solution.
(c)Animal cells become flaccid in isotonic solution.
(d)Plasmolysis of plant cells occurs in hypotonic solution.
(e)Plasmolysis of animal cells occurs in hypotonic solution.
3.What is the force that pushes a plant cell membrane against the cell wall?
(a)hypertonic pressure
(b)turgor pressure
(c)gravity
(d)membrane potential
(e)dynamic equilibrium
4.A beaker is divided by a membrane that is permeable to water and impermeable to sodium ions. The sodium-water solution on side A is more concentrated than the sodium-water solution on side B. Which of the following statements will be true when equilibrium is reached across the membrane?
(a)The absolute number of water molecules will be different on the two sides of the membrane.
(b)Equal numbers of water molecules will exist on each side of the membrane at equilibrium.
(c)Since the solute can't cross the membrane, the solution will not reach equilibrium.
(d)The solute will maintain the original concentration on both sides of the membrane.
(e)All answers are correct.
5.Complete the following sentence: The sodium-potassium pump transports...
(a)three sodium ions from the interior to the exterior of the cell and two potassium ions from the exterior to the interior.
(b)three sodium ions from the exterior to the interior of the cell and two potassium ions from the interior to the exterior.
(c)two sodium ions from the interior to the exterior of the cell and two potassium ions from the exterior to the interior
(d)two sodium ions from the interior to the exterior of the cell and three potassium ions from the exterior to the interior
(e)None of the answers are correct.
6.Which of the events below would likely allow the interior of a cell to become more negatively charged?
(a)A proton pump begins pumping protons out of the cell.
(b)Aquaporins open.
(c)A sodium-potassium pump starts pumping.
(d)Either a proton pump begins pumping protons out of the cell or a sodium-potassium pump starts pumping.
(e)All answers are correct.
7. In neurons, what signal will trigger membrane fusion of docked vesicles?
(a)calcium
(b)neurotransmitters
(c)exocytosis
(d)clathrin
(e)LDL
8. Which of the following would result in the ingestion of a wide variety of soluble nutrients from the environment?
(a)pinocytosis
(b)phagocytosis
(c)receptor-mediated endocytosis
(d)exocytosis
(e)All answers are correct.
9. What is chemotaxis?
(a)movement of chemicals across the membrane
(b)movement in response to a chemical stimulus
(c)movement of chemicals using receptor-mediated endocytosis
(d)movement of chemicals against their concentration gradient
(e)ingestion of materials through phagocytosis
10.Complete the following sentence: Cells without proper LDL receptors will...
(a)need to produce their own cholesterol.
(b)be unable to use cholesterol.
(c)be unable to produce cholesterol.
(d)ingest sufficient LDL from pinocytosis.
(e)be unable to release excess cholesterol.
11. What is the difference between pinocytosis and phagocytosis?
(a)the polarity of the molecule being ingested
(b)Only pinocytosis is used to ingest nutrients.
(c)Pinocytosis is used to ingest larger materials.
(d)Only phagocytosis is used to ingest nutrients.
(e)the size of the molecule being ingested
12. What would happen if a lysosome fused with a mitochondrion?
(a)The lysosome would be digested by the mitochondrion.
(b)The mitochondrion would be secreted out of the cell.
(c)The mitochondrion would be digested.
(d)Nothing would happen; lysosomes only digest foreign cells.
(e)The mitochondrion would absorb the lysosomal membrane.
13. Complete the following sentence: Rapidly growing cells would be performing...
(a)more endocytosis than exocytosis.
(b)more exocytosis than endocytosis.
(c)the same amounts of endocytosis and exocytosis.
(d)neither endocytosis or exocytosis.
(e)mainly phagocytosis.
14. What is the significance of distance in cell-to-cell communication?
(a)Types of signals can be defined according to the distance they travel to reach their targets.
(b)Neighboring cells can communicate with each other, while distant cells are unable to communicate with each other.
(c)Gap junctions allow transduction of the most distant signal.
(d)Synaptic transmission is only effective as a mechanism for distant communication.
(e)None of the answers are correct.
15. Which of the following is true of a receptor tyrosine kinase?
(a)Part of it is exposed to the extracellular space, and part of it is located on the inside of the cell.
(b)It is a cytoplasmic receptor.
(c)It has seven transmembrane-spanning domains.
(d)Dimerization is an optional step in receptor tyrosine kinase activation.
(e)None of the answers are correct.
16. How are G protein-coupled receptors continually made available for reuse?
(a)The G protein-mediated activation of the enzyme is only temporary.
(b)The G protein opens multiple binding sites simultaneously.
(c)When a G protein activates, it diffuses away from the receptor, leaving it available for reuse.
(d)Any signal can bind a G protein-coupled receptor.
(e)None of the answers are correct.
17. Why is the kinase so important in a receptor tyrosine kinase?
(a)Tyrosine kinases activate synapses, triggering cellular responses.
(b)Tyrosine kinase is the signal that the receptor binds.
(c)Kinases transfer phosphates, phosphorylating the receptor.
(d)The tyrosine kinase domains are active in their monomeric states.
(e)The tyrosine kinase uses guanosine triphosphate to become activated.