so biology final cells test
A student placed a semipermeable membrane inside a U-shaped channel with two chambers, as shown. The membrane permits the movement of water but not salt. The student wants to vary the rate of osmosis that occurs across the membrane. Which of the following experimental designs will result in the fastest net rate of water movement into chamber A? A) Placing salt water in chamber A and distilled water in chamber B B) Placing distilled water in both chambers C) Placing distilled water in chamber A and salt water in chamber B D) Placing salt water in both chambers
A) Placing salt water in chamber A and distilled water in chamber B
Which of the following describes the most likely location of cholesterol in an animal cell? A) Embedded in the plasma membrane B) Dissolved in the cytosol C) Suspended in the stroma of the chloroplast D) Bound to free ribosomes
A) Embedded in the plasma membrane
Which of the following is the strongest evidence supporting the endosymbiont hypothesis? A) Mitochondria have their own DNA and divide independently of the cell. B) Mitochondria can carry out hydrolytic reactions on organic molecules. C) Mitochondria have a highly folded membrane. D) Mitochondria are found in both plants and animals.
A) Mitochondria have their own DNA and divide independently of the cell.
Which of the following best explains how the phospholipid bilayer of a transport vesicle contributes to cellular functions? A) The phospholipid bilayer allows the vesicle to fuse with the Golgi apparatus and the plasma membrane, allowing the exocytosis of proteins. B) The phospholipid bilayer physically connects the nuclear envelope to the rough endoplasmic reticulum, thus increasing the rate of transcription and translation. C) The phospholipid bilayer of a transport vesicle contains chemicals that digest the proteins made in the rough endoplasmic reticulum. D) The phospholipid bilayer contains enzymes that catalyze the conversion of hydrogen peroxide to water and oxygen.
A) The phospholipid bilayer allows the vesicle to fuse with the Golgi apparatus and the plasma membrane, allowing the exocytosis of proteins.
Which of the following statements best describes how a growth factor stimulates cell division from outside a cell? A) The growth factor binds to other cells in the same area and holds them together to form a large, multicellular structure. B The growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes. C) The growth factor binds to sugar molecules in the extracellular fluid and provides them to the cell as a source of energy. D) The growth factor binds to phospholipids in the plasma membrane, creating a channel through which substances enter the cell.
B The growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes.
11 Based on Table 1, which of the following percentages is closest to the solute concentration of the grape? A) 0.0% B) 1.3% C) 5.5% D) 10.1%
B) 1.3%
The mechanism of action of many common medications involves interfering with the normal pathways that cells use to respond to hormone signals. Which of the following best describes a drug interaction that directly interferes with a signal transduction pathway? A) A medication causes the cell to absorb more of a particular mineral, eventually poisoning the cell. B) A medication enters the target cell and inhibits an enzyme that normally synthesizes a second messenger. C) A medication enters the target cell's nucleus and acts as a mutagen. D) A medication interrupts the transcription of ribosomal RNA genes.
B) A medication enters the target cell and inhibits an enzyme that normally synthesizes a second messenger.
Use the following information for questions 10-15 A student peeled the skins from grapes, exposing cells with membranes that are only permeable to water and small diffusible solutes. The student measured the mass of the peeled grapes. The student then placed each peeled grape into one of five solutions. After 24 hours, the student removed the peeled grapes from the solutions, measured their final mass, and calculated the percent change in mass (Table 1). TABLE 1. PERCENT CHANGE IN MASS OF PEELED GRAPES IN SOLUTIONS 10 Based on Table 1, which of the following best explains the difference in water potential between certain solutions and the grapes? A) NaCI and tap water have a lower water potential because these two solutions caused the grape to gain water. B) Grape soda and/aye a lower water potential because these two solutions caused the grape to lose water. C) Tap water and NACI grape juice have a lower water potential because these two solutions caused the grape to lose water. D) Grape soda and grape juice have a lower water potential because these two solutions caused the grape to gain water.
B) Grape soda and/aye a lower water potential because these two solutions caused the grape to lose water.
Which of the following best explains how molecules such as Oxygen and Carbon Dioxide can move across the membrane of a cell? A) The majority of the cell membrane contains protein channels that allow this type of molecule into the cell. B) The majority of the cell membrane is nonpolar, which allows small, nonpolar molecules to freely cross. C) The phospholipids of the membrane are tightly packed, so only small molecules and ions can fit between phospholipids. D) ATP is hydrolyzed to provide energy to help Oxygen and Carbon Dioxide move against their concentration gradient and across the membrane.
B) The majority of the cell membrane is nonpolar, which allows small, nonpolar molecules to freely cross.
The primary function of the kidney is to exchange molecules across a membrane between the blood and the urine. One type of kidney cell has a basic rectangular shape, except for a single surface, which is lined with tiny, finger-like projections that extend into the surrounding extracellular space. Which of the following best explains the advantage these projections provide the cell? A) The projections increase the volume of the cell without affecting the surface area, which increases the metabolic needs of the cell. B) The projections increase the surface area-to-volume ratio of the cell, which allows for more efficient nutrient exchange with the environment. C) The projections increase the speed at which an individual molecule can move, resulting in faster nutrient exchange with the environment. D) The projections increase the selectivity of the membrane because the small size of the projections limits the number of transport proteins that can be embedded in the membrane.
B) The projections increase the surface area-to-volume ratio of the cell, which allows for more efficient nutrient exchange with the environment.
A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell. The scientist built a tube that was divided by an artificial membrane and filled with distilled water. The scientist put a known amount of a protein into the water on one side of the membrane. After some time, the scientist measured the concentration of the protein on either side of the membrane but found that there had been no change. Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane? A) Increase the solute concentration in the solution B) Use a small, nonpolar solute instead of a protein C) Increase the temperature of the solution D) Add artificial aquaporins to the membrane
B) Use a small, nonpolar solute instead of a protein
What evolutionary advantage does compartmentalization of core metabolic processes offer eukaryotes? A) Evolution of the mitochondria allowed eukaryotes to perform respiration. B) With the evolution of mitochondria in eukaryotes, the Krebs cycle and electron transport chain also evolved C) Evolution of a nucleus in eukaryotes separates the processes of transcription and translation and they can be regulated separately. D) A nucleus in bacteria provides separation of respiration from transcription
B) With the evolution of mitochondria in eukaryotes, the Krebs cycle and electron transport chain also evolved
Vertebrate immune responses involve communication over short and long distances. Which of the following statements best helps explain how cell surface proteins, such as MHC proteins and T cell receptors, mediate cell communication over short distances? A) The proteins receive electrical signals from nerve cells. B) The proteins leave the cell and travel in the bloodstream to other cells. C The proteins interact directly with proteins on the surfaces of other cells. D) The proteins bind to molecules secreted by cells located in other parts of the body.
C The proteins interact directly with proteins on the surfaces of other cells.
Which of the following processes is most likely to occur as a result of an animal cell receiving a signal to initiate apoptosis? A) Ribosomes will translate mRNA to produce proteins. B) Vesicles will release extracellular growth factors via exocytosis. C) Lysosomes will release digestive enzymes into the cytosol. D) Vacuoles will fuse with the cellular membrane.
C) Lysosomes will release digestive enzymes into the cytosol.
The diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria? A) The organism is surrounded by a cell wall. B) The organism contains ribosomes. C) The organism does not have a nuclear membrane surrounding its genetic material. D) The organism is not capable of making or providing itself with ATP.
C) The organism does not have a nuclear membrane surrounding its genetic material.
The manner in which several different ions and molecules move through a cell membrane is shown in the diagram above. For each ion or molecule, the relative concentration on each side of the membrane is indicated. Which of the following accurately describes one of the movements taking place? A) Glucose is transported into the cell by active transport. B) Na+ is transported into the cell by active transport. C) The movement of glucose through the membrane requires ATP hydrolysis. D) Na* transport out of the cell requires ATP hydrolysis.
D) Na* transport out of the cell requires ATP hydrolysis.
13 Assuming a negligible pressure potential, which of the following best predicts the net movement of the small diffusible solutes and water in the second experiment (Table 2) ? A) Small diffusible solutes will diffuse into the grape cells, followed by water. B) Small diffusible solutes will diffuse out of the grape cells and water will diffuse into the cells. C) Small diffusible solutes will diffuse out of the grape cells, followed by water. D) Small diffusible solutes will diffuse into the grape cells and water will diffuse out of the cells.
D) Small diffusible solutes will diffuse into the grape cells and water will diffuse out of the cells.
14 Mercurial sulfhydryl is an inhibitor of aquaporins. Which of the following is the most likely effect of adding mercurial sulfhydryl to the distilled water solution? A) The grape cells will burst because of excess water entering by active transport. B) The grape cells will gain more water because of the activation of the transport protein. C) CThe grape cells will shrink because active transport has been inhibited. D) The grape cells will gain water more slowly because of a lack of facilitated diffusion.
D) The grape cells will gain water more slowly because of a lack of facilitated diffusion.
12 A student hypothesizes that the solute concentration of grape juice is higher than the solute concentration of the actual grape because the grape juice has added sugar. Based on the data in Table 1, which of the following best evaluates the student's hypothesis? A) The hypothesis is supported because the mass of the grape decreased in the grape juice. B The hypothesis is supported because the grape juice has a greater solute potential than the grape has. C) The hypothesis is not supported because the grape was isotonic to the grape juice. D) The hypothesis is not supported because the mass of the grape increased in the grape juice.
D) The hypothesis is not supported because the mass of the grape increased in the grape juice.
15 Which of the following best explains why larger grapes have a different rate of water absorption per gram of mass than smaller grapes do? A) The rate is slower because smaller grapes have a larger surface-area-to-volume ratio than the larger grapes do. B) The rate is slower because larger grapes have a larger surface-area-to-volume ratio than the smaller grapes do. C) The rate is slower because smaller grapes can expand more than larger grapes to hold excess water. D) The rate is slower because larger grapes have more volume to hold excess water than smaller grapes do.
D) The rate is slower because larger grapes have more volume to hold excess water than smaller grapes do.
