AP BIO 2 MIDTERM

1) Use the following figure to answer the question. The molecule shown is ________. A) a hexose B) a pentose C) fructose D) maltose

A

15) How do cells use the ATP cycle illustrated in the figure? A) Cells use the cycle to recycle ADP and phosphate. B) Cells use the cycle to recycle energy released by ATP hydrolysis. C) Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis. D) Cells use the cycle primarily to generate heat.

A

16) Which of the following is a major difference between RNA and DNA? A) type of sugar B) type of phosphate C) type of purines D) type of glycosidic bond

A

19) Cells require which of the following to form cilia or flagella? A) tubulin B) laminin C) actin D) intermediate filaments

A

19) Homo sapiens have 23 pairs of chromosomes. This implies that ________. A) 46 double-stranded DNA molecules are present in each somatic cell B) 23 single-stranded DNA molecules are present in each somatic cell C) 23 double-stranded DNA molecules are present in each somatic cell D) several hundreds of genes are present on DNA but not on the chromosomes

A

2) According to the fluid mosaic model of cell membranes, phospholipids ________. A) can move laterally along the plane of the membrane B) frequently flip-flop from one side of the membrane to the other C) occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane D) have hydrophilic tails in the interior of the membrane

A

22) In plant cells, the middle lamella ________. A) glues adjacent cells together B) prevents dehydration of adjacent cells C) connects the cytoplasm of adjacent cells D) prevents excessive uptake of water by plant cells

A

27) Familial hypercholesterolemia is characterized by ________. A) defective LDL receptors on the cell membranes B) poor attachment of the cholesterol to the extracellular matrix of cells C) a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes D) inhibition of the cholesterol active transport system in red blood cells

A

28) Which of the following molecules is polar? C3H7OH C2H5COOH A) C3H7OH and C2H5COOH are both polar molecules. B) Neither C2H5COOH or C3H7OH is polar. C) C2H5COOH is polar, but C3H7OH is not polar. D) C2H5COOH is not polar, but C3H7OH is polar.

A

29) Characterization of the complete three-dimensional structure of a newly purified protein suggests that it catalyzes the breakdown of a large substrate. The protein consists of a single polypeptide chain. It has a large pocket that appears to be the binding site for the substrate and a smaller indentation that appears to be the binding site for a regulatory molecule. What do these structural observations suggest about the mechanism by which the activity of this protein is likely regulated? A) It is probably an enzyme that is regulated by noncompetitive inhibition. B) It is probably a multi-subunit enzyme that is regulated by allosteric regulation. C) It is probably an enzyme that is regulated by competitive inhibition. D) It is probably an enzyme that is regulated by cooperativity.

A

29) Thermal energy of the water in a bathtub is ________ than in a freshly brewed coffee pot because of its ________. A) higher; greater volume B) higher; high kinetic energy C) lower; low temperature D) lower; low density

A

3) Which of the following terms most precisely describes the cellular process of breaking down large molecules into smaller ones? A) catabolism (catabolic pathways) B) metabolism C) anabolism (anabolic pathways) D) dehydration

A

30) In addition to activating or inhibiting enzymes through allosteric regulation, what other means does a cell use to control enzymatic activity? A) localization of enzymes into specific organelles or membranes B) secretion of enzymes out of the cell C) assembly of enzymes into large aggregates D) altering internal pH

A

35) As the [H3O+] of the solution decreases, the [OH-] ________. A) increases and thus pH increases B) increases and thus pH decreases C) decreases and thus the pH decreases D) decreases and thus the pH increases

A

4) Which of the following statements describes the first law of thermodynamics? A) Energy cannot be created or destroyed. B) The entropy of the universe is decreasing. C) The entropy of the universe is constant. D) Energy cannot be transferred or transformed.

A

40) The application of scientific knowledge for some specific purpose is known as ________. A) technology B) deductive science C) inductive science D) pure science

A

7) The relation between amino acid and polypeptide is similar to the relation between ________. A) nucleotide and nucleic acid B) triglycerides and steroids C) phospholipid and plasma membrane D) glycogen and glucose

A

8) Which of the following is a major difference between RNA and DNA? A) type of sugar B) type of phosphate C) type of purines D) type of glycosidic bond

A

9) A cell with a predominance of rough endoplasmic reticulum is most likely ________. A) producing large quantities of proteins for secretion B) producing large quantities of proteins in the cytosol C) producing large quantities of carbohydrates to assemble an extensive cell wall matrix D) producing large quantities of carbohydrates for storage in the vacuole

A

9) A chemical reaction that has a positive ΔG is best described as ________. A) endergonic B) enthalpic C) spontaneous D) exergonic

A

9) Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures? A) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. B) Unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly. C) Unsaturated fatty acids are more nonpolar than saturated fatty acids. D) The double bonds block interaction among the hydrophilic head groups of the lipids.

A

10) The relationship between catabolism and anabolism is most similar to the relationship between which of the following pairs of terms? A) exergonic; spontaneous B) exergonic; endergonic C) free energy; entropy D) work; free energy

B

11) Which of the following statements describes a central role that ATP plays in cellular metabolism? A) Hydrolysis of ATP provides an input of free energy for exergonic reactions. B) ATP provides energy coupling between exergonic and endergonic reactions. C) Hydrolysis of the terminal phosphate group stores free energy that is used for cellular work. D) Its terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules.

B

15) The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. Which of the following will be true when the system illustrated above reaches equilibrium? A) The concentration of sucrose on side A will be greater than the concentration of sucrose on side B. B) The water level will be higher in side A than in side B. C) The water levels will be unchanged. D) The water level will be higher in side B than in side A.

B

16) The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. At the beginning of the U-tube experiment illustrated above, which of the following statements is true? A) Side A is hypertonic to side B. B) Side A is hypotonic to side B. C) Side A is hypertonic to side B with respect to glucose. D) Side A is hypotonic to side B with respect to NaCl.

B

16) Which of the following is true when comparing an uncatalyzed reaction to the same reaction with a catalyst? A) The catalyzed reaction will be slower. B) The catalyzed reaction will have the same ∆G. C) The catalyzed reaction will have higher activation energy. D) The catalyzed reaction will consume all of the catalyst.

B

18) During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction? A) -40 kcal/mol B) -20 kcal/mol C) -10 kcal/mol D) +20 kcal/mol

B

18) Which of the following statements about the 5 end of a polynucleotide strand of RNA is correct? A) The 5 end has a hydroxyl group attached to the number 5 carbon of ribose. B) The 5 end has a phosphate group attached to the number 5 carbon of ribose. C) The 5 end has phosphate attached to the number 5 carbon of the nitrogenous base. D) The 5 end has a carboxyl group attached to the number 5 carbon of ribose.

B

19) In which of the following environments would there be the greatest need for osmoregulation? A) an animal connective tissue cell bathed in isotonic body fluid B) a salmon moving from a river into an ocean C) a red blood cell surrounded by plasma D) a plant being grown hydroponically in a watery mixture of designated nutrients

B

19) One of the primary functions of RNA molecules is to ________. A) transmit genetic information to offspring B) function in the synthesis of proteins C) make a copy of itself, thus ensuring genetic continuity D) act as a pattern or blueprint to form DNA

B

2) A glycosidic linkage is analogous to which of the following in proteins? A) an amino group B) a peptide bond C) a disulfide bond D) a β pleated sheet

B

2) Most cells cannot harness heat to perform work because ________. A) heat is not a form of energy B) temperature is usually uniform throughout a cell C) heat can never be used to do work D) heat must remain constant during work

B

20) A sodium-potassium pump ________. A) moves three potassium ions out of a cell and two sodium ions into a cell while producing ATP for each cycle B) moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis C) moves three potassium ions out of a cell and two sodium ions into a cell using energy from ATP hydrolysis D) move three sodium ions out of a cell and two potassium ions into a cell and generates an ATP in each cycle

B

21) Which of the following membrane activities requires energy from ATP hydrolysis? A) facilitated diffusion of chloride ions across the membrane through a chloride channel B) movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid C) movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell D) movement of carbon dioxide out of a paramecium

B

24) Use the following information to answer the question below. The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following terms best describes the forward reaction in the figure? A) endergonic, ∆G > 0 B) exergonic, ∆G < 0 C) endergonic, ∆G < 0 D) exergonic, ∆G > 0

B

24) Which two functional groups are always found in amino acids? A) carbonyl and amino groups B) carboxyl and amino groups C) amino and sulfhydryl groups D) hydroxyl and carboxyl groups

B

25) Both the volume and the surface area for three different cells were measured. These values are listed in the following table: Using data from the table above, select the best explanation for why that cell will be able to eliminate waste most efficiently? A) Cell 1, since it has the smallest volume and will not produce as much waste as the other cells. B) Cell 2, since it has the highest ratio of surface area to volume, which facilitates the exchange of materials between a cell and its environment. C) Cell 3, since it has the largest surface area, which will enable it to eliminate all of its wastes efficiently. D) Cell 3, because it is big enough to allow wastes to easily diffuse through the plasma membrane.

B

25) The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A) C60H120O60 B) C60H102O51 C) C60H100O50 D) C60H111O51

B

25) Use the following information to answer the question below. The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure? A) a B) b C) c D) d

B

27) Use the figure to answer the question. Thalidomide and L-dopa (see figure) are examples of pharmaceutical drugs that occur as enantiomers, or molecules that ________. A) have identical three-dimensional shapes B) are mirror images of one another C) are mirror images of one another and have the same biological activity D) are cis-trans isomers

B

27) Water has many exceptional and useful properties. Which is the rarest property among compounds? A) Water is a solvent. B) Solid water is less dense than liquid water. C) Water has a high heat capacity. D) Water has surface tension.

B

28) A series of enzymes catalyze the reactions in the metabolic pathway X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as ________. A) an allosteric inhibitor B) the substrate C) an intermediate D) a competitive inhibitor

B

29) A patient was involved a serious accident and lost a large quantity of blood. In an attempt to replenish body fluids, distilled water—equal to the volume of blood lost—is added to the blood directly via one of his veins. What will be the most probable result of this transfusion? A) The patient's red blood cells will shrivel up because the blood has become hypotonic compared to the cells. B) The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells. C) The patient's red blood cells will shrivel up because the blood has become hypertonic compared to the cells. D) The patient's red blood cells will burst because the blood has become hypertonic compared to the cells.

B

29) Which domains of life are classified as prokaryotes? A) Bacteria and Eukarya B) Bacteria and Archaea C) Archaea and Fungi D) Bacteria and Protista

B

29) Which two functional groups are always found in amino acids? A) carbonyl and amino groups B) carboxyl and amino groups C) amino and sulfhydryl groups D) hydroxyl and carboxyl groups

B

3) According to the fluid mosaic model, a membrane ________. A)is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins B)is composed of a single layer of fluid phospholipids between two layers of hydrophilic proteins C)is composed of a mosaic of fluid polysaccharides and amphipathic proteins D)is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins

B

31) Three lab groups carried out an experiment to identify the concentration of sucrose in six solutions. Each unknown contained one of the following sucrose concentrations: 0.0 M, 0.2 M, 0.4 M, 0.6 M, 0.8 M, and 1.0 M. Cubes of sweet potato (1 cm3) were soaked for 24 hours in each solution and weighed to determine the change in mass. Each data entry represents the average of three sample replicates expressed as percent change in mass following a 24-hour soak in the unknown solutions. Based on the data provided, the intracellular molarity of dissolved solutes in sweet potato cells is approximately ________. A) 0.2 M B) 0.4 M C) 0.6 M D) 0.8 M

B

33) Which of the functional groups is not reactive but serves as a recognizable tag on the DNA molecule and alter the expression of genes in the cells. A) amino B) methyl C) carboxyl D) hydroxyl

B

34) A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound ________. A) lacks an asymmetric carbon and is probably a fat or lipid B) should dissolve in water C) should dissolve in a nonpolar solvent D) will not form hydrogen bonds with water

B

4) Which of the following provides the information necessary to stipulate a protein's 3-D shape? A) peptide bonds between different amino acids B) sequence of amino acids in the polypeptide chain C) side chains of various amino acids D) number of water molecules in the vicinity

B

6) Use the following figure to answer the question. The chemical reaction illustrated ________. A) is a hydrolysis reaction B) results in a peptide bond C) joins two fatty acids together D) links two polymers to form a monomer

B

6) Which of the following statements is consistent with the second law of thermodynamics? A) A gain of free energy in a system is always associated with conversion of energy from one form to another. B) A constant input of energy is required to maintain the high level of cellular organization. C) Without an input of energy, the entropy of an organism would tend to decrease over time. D) Every energy transformation performed by an organism decreases the entropy of the universe.

B

Human immunodeficiency virus (HIV) infects cells that have both CD4 and CCR5 cell surface molecules. The viral nucleic acid molecules are enclosed in a protein capsid, and the protein capsid is itself contained inside an envelope consisting of a lipid bilayer membrane and viral glycoproteins. One hypothesis for viral entry into cells is that binding of HIV membrane glycoproteins to CD4 and CCR5 initiates fusion of the HIV membrane with the plasma membrane, releasing the viral capsid into the cytoplasm. An alternative hypothesis is that HIV gains entry into the cell via receptor-mediated endocytosis, and membrane fusion occurs in the endocytotic vesicle. To test these alternative hypotheses for HIV entry, researchers labeled the lipids on the HIV membrane with a red fluorescent dye. 30) What would be observed by live-cell fluorescence microscopy immediately after HIV entry if HIV is endocytosed first, and then later fuses with the endocytotic vesicle membrane? A) A spot of red fluorescence will be visible on the infected cell's plasma membrane, marking the site of membrane fusion and HIV entry. B) The red fluorescent dye-labeled lipids will appear in the infected cell's interior. C) A spot of red fluorescence will diffuse in the infected cell's cytoplasm. D) A spot of red fluorescence will remain outside the cell after delivering the viral capsid.

B

1) For a protein to be an integral membrane protein, it would have to be ________. A) hydrophilic B) hydrophobic C) amphipathic, with at least one hydrophobic region D) exposed on only one surface of the membrane

C

1) Which of the following statements is true of metabolism in its entirety in all organisms? A) Metabolism depends on a constant supply of energy from food. B) Metabolism uses all of an organism's resources. C) Metabolism consists of all the energy transformation reactions in an organism. D) Metabolism manages the increase of entropy in an organism.

C

11) Which of the following would likely diffuse through the lipid bilayer of a plasma membrane most rapidly? A) sucrose B) an amino acid C) O2 D) Na+

C

12) Which of the following molecules is most similar in structure to ATP? A) a pentose sugar B) a DNA nucleotide C) an RNA nucleotide D) an amino acid with three phosphate groups attached

C

13) Which of the following processes includes all of the others? A) osmosis B) facilitated diffusion C) passive transport D) transport of an ion down its electrochemical gradient

C

14) A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases, although they do not often hydrolyze ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a resting muscle cell's cytosol has a free calcium ion concentration of 10-7 while the concentration in the SR is 10-2, then how is the ATPase acting? A) ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR. B) ATPase activity must be transferring Pi to the SR to enable this to occur. C) ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. D) ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient.

C

14) Which of the following statements correctly describes osmosis? A) Osmosis only takes place in red blood cells. B) Osmosis is an energy-demanding or "active" process. C) In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. D) In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.

C

17) Five dialysis bags, constructed of a type of membrane that is permeable to water and impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed), and the percent change in mass of each bag was graphed. Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment? A) A B) B C) C D) D

C

18) What will happen to a red blood cell (RBC), which has an internal ion content of about 0.9%, if it is placed into a beaker of pure water? A) The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. B) The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the RBC. C) The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. D) The cell will remain the same size because the solution outside the cell is isotonic.

C

20) Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls? A) desmosomes B) gap junctions C) plasmodesmata D) tight junctions

C

20) Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as ________. A) a noncompetitive inhibitor of the enzyme B) an allosteric activator of the enzyme C) a cofactor necessary for enzyme activity D) a coenzyme derived from a vitamin

C

21) Which of the following graphs most likely describes the effect of pH on the function of the enzyme catalase in human cells? Note: The x-axis is pH and the y-axis is enzyme activity. A) B) C) D)

C

22) Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant. For the enzyme-catalyzed reaction shown in the figure, if the initial reactant concentration is 1.0 micromolar, which of these treatments will cause the greatest increase in the rate of the reaction? A) doubling the activation energy needed B) cooling the reaction by 10°C C) doubling the enzyme concentration D) increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1/2

C

23) H. V. Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted intercellular junctions, and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species. How do you explain the results of Wilson's experiments? A) The two species of sponge had different enzymes that functioned in the reassembly process. B) The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment. C) The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge. D) One cell functioned as an organizer for each organism, thereby attracting only cells of the same species.

C

24) Gaucher disease is the most common of lipid storage diseases in humans. It is caused by a deficiency of an enzyme necessary for the breakdown of lipids. This leads to the accumulation of fatty material in organs of the body including the spleen, liver, kidneys, lungs, brain, and bone marrow. Using your knowledge of the structure of eukaryotic cells, identify the statement below that best explains how internal membranes and the organelles of cells may be involved in Gaucher disease. A) The mitochondria are most likely defective and do not produce adequate amounts of ATP needed for cellular energy. B) The rough endoplasmic reticulum contains too many ribosomes, which results in an overproduction of the enzyme involved in lipid breakdown. C) The lysosomes lack sufficient amounts of enzymes necessary for the metabolism of lipids. D) The Golgi apparatus produces vesicles with faulty membranes, which fail to be transported to the plasma membrane for secretion.

C

26) An organism with a cell wall would most likely be unable to take in materials through ________. A) osmosis B) active transport C) phagocytosis D) facilitated diffusion

C

26) In a metabolic pathway, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of malonic acid reduces the inhibitory effect of malonic acid. Which of the following statements correctly describes the role played by molecules described in the reaction? A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate in the reaction. B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate in the reaction. C) Succinate is the substrate, and fumarate is the product in the reaction. D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor in the reaction.

C

26) Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely malfunctioning in this disease? A) lysosomes B) Golgi apparatus C) mitochondria D) smooth endoplasmic reticulum

C

27) Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? A) membrane proteins of the inner nuclear envelope B) free ribosomes and ribosomes attached to the ER C) components of the cytoskeleton D) cellulose fibers in the cell wall

C

28) In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? A) on the outside of vesicles B) on the inside surface of the cell membrane C) on the inside surface of the vesicle D) on the outer surface of the nucleus

C

28) Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to ________. A) form cleavage furrows during cell division B) migrate by amoeboid movement C) separate chromosomes during cell division D) maintain the shape of the nucleus

C

30) Which structure is common to plant and animal cells? A) chloroplast B) central vacuole C) mitochondrion D) centriole

C

36) Low humidity in the atmosphere on a hot day ________. A) helps in cooling because skin absorbs water from the atmosphere B) does not help in cooling because water evaporates from the skin faster C) helps in cooling because water evaporates from the skin faster D) does not help in cooling because skin absorbs water from the atmosphere

C

4) Which of the following types of molecules are hydrophilic and therefore excluded from the hydrophobic portion of the phospholipid bilayer? A) transmembrane proteins B) integral membrane proteins C) peripheral membrane proteins D) cholesterol

C

5) Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? A) Living organisms do not obey the second law of thermodynamics, which states that the entropy of an organism increases with each energy transformation. B) The decrease in entropy is associated with growth of an organism. As a consequence of growth, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their increased complexity. C) As a consequence of growth, the decrease in entropy of the organism is associated with a corresponding decrease in the entropy of the universe. D) Living organisms are able to transform chemical energy into entropy.

C

5) Which of the following is a major difference between prokaryotic cells and eukaryotic cells? A) Prokaryotic cells have cell walls, while eukaryotic cells do not. B) Eukaryotic cells have flagella, while prokaryotic cells do not. C) Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not. D) Prokaryotic cells are generally larger than eukaryotic cells.

C

6) For lipids to be fluid at room temperature, they should have ________. A) single bonds only B) a higher number of glycerol molecules C) a higher number of cis double bonds D) a longer carbon chain

C

6) You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume? A) Pinch the edges of the cube into small folds. B) Flatten the cube into a pancake shape. C) Round the clay up into a sphere. D) Stretch the cube into a long, shoebox shape.

C

7) Which component in the accompanying figure is a microfilament (actin filament) of the cytoskeleton? A) A B) B C) C D) D

C

8) Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature? A) Since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical. B) Since cell membranes communicate signals from one organism to another, the cell membranes must be asymmetrical. C) The two sides of a cell membrane face different environments and carry out different functions. D) Proteins only function on the cytoplasmic side of the cell membrane, which results in the membrane's asymmetrical nature.

C

20) Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted. A) B) C) D)

C (the pic shown is put with answer choice C)

32) Which of the pairs of molecular structures shown depict enantiomers (enantiomeric forms) of the same molecule? A) B) C) D)

C (the pic shown is put with answer choice C)

"The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16) Hemoglobin is ________. A) a tertiary protein with two polypeptides B) a quaternary protein with two polypeptides C) a tertiary protein with four polypeptides D) a quaternary protein with four polypeptides

D

10) Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane? A) large hydrophobic molecules B) small hydrophobic molecules C) carbon dioxide D) small ions

D

12) A research team is working on the design of a new drug for the treatment of lung cancer. To be most effective, this drug must specifically enter the cytoplasm of lung cells while not entering the cells of other tissues. Which of the following characteristics would likely enhance the specificity of this drug? A) the relative hydrophobicity of the drug molecule B) phospholipid composition of lung cell plasma membranes C) specificity of the drug molecule for binding to the extracellular matrix of lung cells D) similarity of the drug molecule to other molecules normally transported lung cells

D

13) When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? A) It is used to power yet more cellular work. B) It is captured to store energy as more ATP. C) It is used to generate ADP from nucleotide precursors. D) It is lost to the environment.

D

16) Cilia and flagella bend because of ________. A) conformational changes in ATP that thrust microtubules laterally B) a motor protein called radial spokes C) contraction by myosin D) a motor protein called dynein

D

17) The following question is based on the 15 molecules illustrated in the figure. Which molecule is a saturated fatty acid? A) 1 B) 5 C) 8 D) 9

D

17) Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions? A) The enzyme contains α-helices and β-pleated sheets. B) The enzyme is subject to competitive inhibition and allosteric regulation. C) The enzyme is composed of at least two subunits. D) Either the enzyme has two distinct active sites or the substrates involved in the two reactions have very similar structures.

D

19) Which of the following statements describes a key component of the induced fit hypothesis of enzyme catalysis? A) Substrate binds to an allosteric site rather than to the active site of an enzyme. B) Binding of an activator molecule changes the shape of the active site of an enzyme. C) The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme. D) Binding of substrate to the active site changes the shape of the active site of an enzyme.

D

2) In the fractionation of homogenized cells using differential centrifugation, which of the following will require the greatest speed to form pellets at the bottom of the tube? A) nuclei B) mitochondria C) chloroplasts D) ribosomes

D

21) Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through ________. A) plasmodesmata B) tight junctions C) desmosomes D) gap junctions

D

22) Diffusion of ions across membranes through specific ion channels is driven by ________. A) active transport pumps B) ion concentration gradients only C) electrical gradients only D) ion electrochemical gradients

D

23) The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane—more acidic outside the cell than inside the cell. In this bacterial cell, phosphate transport is an example of ________. A) passive diffusion B) facilitated diffusion C) active transport D) cotransport

D

23) Use the following information to answer the question below. Activity of various enzymes at various temperatures (a) and at various pH (b) Which curves on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher? A) curves 1 and 5 B) curves 2 and 5 C) curves 3 and 4 D) curves 3 and 5

D

24) Which of the following statements is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal? A) Sodium and glucose compete for the same binding site in the cotransporter. B) Glucose entering the cell down its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient. C) Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. D) A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.

D

25) Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following types of treatments? A) antiviral medications that are efficient and work well with most viruses B) intravenous feeding techniques C) medications to slow blood loss D) hydrating drinks with high concentrations of salt and glucose

D

27) HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called protease. Once the enzyme's structure was known, researchers began looking for drugs that would fit into the active site and block it. If this strategy for stopping HIV infections were successful, it would be an example of what phenomenon? A) noncompetitive inhibition B) denaturation C) allosteric regulation D) competitive inhibition

D

4) What makes lipids/fats hydrophobic? A) their long carbon skeleton B) the carboxyl group at one end of the molecule C) the glycerol moiety D) presence of relatively nonpolar C—H bonds

D

5) Why are lipids and proteins free to move laterally in membranes? A) The interior of the membrane is filled with liquid water. B) Lipids and proteins repulse each other in the membrane. C) Hydrophilic portions of the lipids are in the interior of the membrane. D) There are only weak hydrophobic interactions in the interior of the membrane.

D

6) Which component in the accompanying figure is cholesterol? A) B B) C C) D D) E

D

7) Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true? A) By resulting in such diversity and complexity of life, it is an exception to the second law of thermodynamics. B) It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the entropy of the planet. C) It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the total energy in the universe. D) It has occurred in accordance with the laws of thermodynamics and resulted in a substantial decrease in the entropy of the planet.

D

8) Which of the following statements is true for a system at chemical equilibrium? A) The system consumes energy at a steady rate. B) The system releases energy at a steady rate. C) The kinetic energy of the system is zero. D) The system can do no work.

D

"The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16) Hemoglobin, when subjected to 40% acetonitrile at pH 10.0, loses its quaternary structure, which means the ________. A) four α and β polypeptides dissociate B) peptide bonds between amino acids break C) α and β polypeptides lose their 3-D structure D) four α and β polypeptides dissociate, peptide bonds between amino acids, and α and β polypeptides lose their 3-D structure

A

10) The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Hydrogenated vegetable oil ________. A) is solid at room temperature B) has more "kinks" in the fatty acid chains C) has fewer trans fatty acids D) is less likely to clog arteries

A

11) One of the primary functions of RNA molecules is to ________. A) transmit genetic information to offspring B) function in the synthesis of proteins C) make a copy of itself, thus ensuring genetic continuity D) act as a pattern or blueprint to form DNA

A

21) The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the form. Which of the following could amylase break down? A) glycogen, starch, and amylopectin B) glycogen and cellulose C) cellulose and chitin D) starch, chitin, and cellulose

A

15) If one strand of a DNA molecule has the sequence of bases 5′-ATTGCA-3′, the mRNA synthesized following the template will be ________. A) 5′-TAACGT-3′ B) 5′-TGCAAT-3′ C) 3′-UAACGU-5′ D) 5′-UGCAAU-3′

A

15) The relation between amino acid and polypeptide is similar to the relation between ________. A) nucleotide and nucleic acid B) triglycerides and steroids C) phospholipid and plasma membrane D) glycogen and glucose

A

16) The central rule of molecular biology states that ________. A) DNA is transcribed into RNA, which is translated into protein B) DNA is translated into protein C) DNA is translated into RNA, which is transcribed into protein D) RNA is transcribed into protein

A

17) Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein in the red blood cells (RBCs). What do you suspect is the consequence of such a defect? A) abnormally shaped RBCs B) an insufficient supply of ATP in the RBCs C) an insufficient supply of oxygen-transporting proteins in the RBCs D) adherence of RBCs to blood vessel walls, causing plaque formation

A

17) When nucleotides polymerize to form a nucleic acid, ________. A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second C) covalent bonds form between the bases of two nucleotides D) hydrogen bonds form between the bases of two nucleotides

A

22) Which of the following molecules is polar? C3H7OH C2H5COOH A) C3H7OH and C2H5COOH are both polar molecules. B) Neither C2H5COOH or C3H7OH is polar. C) C2H5COOH is polar, but C3H7OH is not polar. D) C2H5COOH is not polar, but C3H7OH is polar.

A

23) The structural level of a protein least affected by a disruption in hydrogen bonding is the A) primary level. B) secondary level. C) tertiary level. D) quaternary level.

A

3) Which of the following statements is true for lipids? A) Lipids are true polymers. B) Waxes and pigments are not lipids. C) Lipids mix poorly with water. D) Lipids are true polymers and mix poorly with water.

A

30) Which of the following is an example of qualitative data? A) The fish swam in a zigzag motion. B) The contents of the stomach are mixed every 20 seconds. C) The temperature decreased from 20°C to 15°C. D) The six pairs of robins hatched an average of three chicks each.

A

32) Consider the following reaction at equilibrium: CO2 + H2O<-->H2CO3. What would be the effect of adding additional H2O? A) It would drive the equilibrium dynamics to the right. B) It would drive the equilibrium dynamics to the left. C) Nothing would happen because the reactants and products are in equilibrium. D) Reactions in both the directions will slow down.

A

38) Which statement is true of all atoms that are anions? A) The atom has more electrons than protons. B) The atom has more protons than electrons. C) The atom has fewer protons than does a neutral atom of the same element. D) The atom has more neutrons than protons.

A

5) Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules because they ________. A) do not have a polar or charged region B) do not have a nonpolar region C) have hydrophobic and hydrophilic regions D) are highly reduced molecules

A

9) When nucleotides polymerize to form a nucleic acid, ________. A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second C) covalent bonds form between the bases of two nucleotides D) hydrogen bonds form between the bases of two nucleotides

A

10) Which organelle often takes up much of the volume of a plant cell? A) lysosome B) central vacuole C) Golgi apparatus D) chloroplast

B

11) Which structure below is independent of the endomembrane system? A) nuclear envelope B) chloroplast C) Golgi apparatus D) plasma membrane

B

12) If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? A) DNA B) RNA C) both DNA and RNA D) polypeptides

B

12) In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and ________. A) combine the hydrogen with water molecules to generate hydrogen peroxide B) combine the hydrogen with oxygen molecules to generate hydrogen peroxide C) combine the hydrogen with hydrogen peroxide to generate oxygen D) combine the hydrogen with hydrogen peroxide to generate oxygen and water

B

13) Which of the following provides the information necessary to stipulate a protein's 3-D shape? A) peptide bonds between different amino acids B) sequence of amino acids in the polypeptide chain C) side chains of various amino acids D) number of water molecules in the vicinity

B

14) In an RNA sample, ________. A) the number of thiamine may or may not equal the number of adenine B) the number of purine always equals the number of pyrimidine C) the number of thiamine always equals the number of uracil D) the number of purine may or may not equal the number of and pyrimidine

B

18) A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism is more closely related to ________. A) humans than to frogs B) frogs than to humans C) rats than to frogs D) gibbons than to rats

B

21) Use the figure to answer the question. Thalidomide and L-dopa (see figure) are examples of pharmaceutical drugs that occur as enantiomers, or molecules that ________. A) have identical three-dimensional shapes B) are mirror images of one another C) are mirror images of one another and have the same biological activity D) are cis-trans isomers

B

22) Which of the following is true of unsaturated fats? A) They are more common in animals than in plants. B) They have double bonds in their fatty acid chains. C) They generally solidify at room temperature. D) They contain more hydrogen than do saturated fats having the same number of carbon atoms.

B

23) A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound ________. A) lacks an asymmetric carbon and is probably a fat or lipid B) should dissolve in water C) should dissolve in a nonpolar solvent D) will not form hydrogen bonds with water

B

24) Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A) The two strands of the double helix would separate. B) The phosphodiester linkages of the polynucleotide backbone would be broken. C) The pyrimidines would be separated from the deoxyribose sugars. D) All bases would be separated from the deoxyribose sugars.

B

28) Which of the following effects can occur because of the high surface tension of water? A) Lakes cannot freeze solid in winter, despite low temperatures. B) A raft spider can walk across the surface of a small pond. C) Organisms can resist temperature changes, although they give off heat due to chemical reactions. D) Sweat can evaporate from the skin, helping to keep people from overheating.

B

31) A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4? A) 5 times more B) 10 times more C) 100 times more D) 1000 times more

C

1) One primary advantage of light microscopy over electron microscopy is that ________. A) light microscopy provides for higher magnification than electron microscopy B) light microscopy provides for higher resolution than electron microscopy C) light microscopy allows the visualization of dynamic processes in living cells D) light microscopy provides higher contrast than electron microscopy

C

13) The evolution of eukaryotic cells most likely involved ________. A) endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into chloroplasts B) endosymbiosis of a photosynthetic archaeal cell in a larger bacterial host cell to escape toxic oxygen—the anaerobic archaea evolved into chloroplasts C) endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria D) evolution of an endomembrane system and subsequent evolution of mitochondria from a portion of the smooth endoplasmic reticulum

C

13) Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base and a phosphate group B) a nitrogenous base and a sugar C) a nitrogenous base, a phosphate group, and a sugar D) a sugar and a purine or pyrimidine

C

25) Amino acids are acids because they always possess ________ as the functional group? A) amino B) carbonyl C) carboxyl D) phosphate

C

26) Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A) 5′-AGCT-3′ with 5′-TCGA-3′ B) 5′-GCGC-3′ with 5′-TATA-3′ C) 5′-ATGC-3′ with 5′-GCAT-3′ D) All of these pairs are correct.

C

3) Which of the following would be most appropriate method to observe the three-dimensional structure and organization of microvilli on an intestinal cell? A) a hand lens (magnifying glass) B) standard light microscopy C) scanning electron microscopy D) transmission electron microscopy

C

34) Which of the following is the best description of an atom's physical structure? A) An atom is a solid mass of material. B) The particles that form an atom are equidistant from each other. C) Atoms are little bubbles of space with mass concentrated at the center of the bubble. D) Atoms are little bubbles of space with mass concentrated on the outside surface of the bubble.

C

35) When are atoms most stable? A) when they have the fewest possible valence electrons B) when they have the maximum number of unpaired electrons C) when all of the electron orbitals in the valence shell are filled D) when all electrons are paired

C

37) The loss of water from a plant by transpiration cools the leaf. Movement of water in transpiration requires both adhesion to the conducting walls and wood fibers of the plant and cohesion of the molecules to each other. A scientist wanted to increase the rate of transpiration of a crop species to extend its range into warmer climates. The scientist substituted a nonpolar solution with an atomic mass similar to that of water for hydrating the plants. What do you expect the scientist's data will indicate from this experiment? A) The rate of transpiration will be the same for both water and the nonpolar substance. B) The rate of transpiration will be slightly lower with the nonpolar substance as the plant will not have evolved with the nonpolar compound. C) Transpiration rates will fall to zero as nonpolar compounds do not have the properties necessary for adhesion and cohesion. D) Transpiration rates will increase as nonpolar compounds undergo adhesion and cohesion with wood fibers more readily than water.

C

40) Which of the following statements best distinguishes hypotheses from theories in science? A) Theories are hypotheses that have been proved. B) Hypotheses are guesses; theories are correct answers. C) Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. D) Theories are proved true; hypotheses are often contradicted by experimental results.

C

7) How do phospholipids interact with water molecules? A) The polar heads avoid water; the nonpolar tails attract water (because water is polar and opposites attract). B) Phospholipids do not interact with water because water is polar and lipids are nonpolar. C) The polar heads interact with water; the nonpolar tails do not. D) Phospholipids dissolve in water.

C

7) Which of the following macromolecules leave the nucleus of a eukaryotic cell through pores in the nuclear membrane? A) DNA B) amino acids C) mRNA D) phospholipids

C

8) Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules? A) polysaccharides B) proteins C) lipids D) nucleic acids

C

8) Phospholipids and triglycerides both ________. A) contain serine or some other organic compound B) have three fatty acids C) have a glycerol backbone D) have a phosphate

C

10) Which of the following statements about the 5 end of a polynucleotide strand of RNA is correct? A) The 5 end has a hydroxyl group attached to the number 5 carbon of ribose. B) The 5 end has a phosphate group attached to the number 5 carbon of ribose. C) The 5 end has phosphate attached to the number 5 carbon of the nitrogenous base. D) The 5 end has a carboxyl group attached to the number 5 carbon of ribose.

D

11) Which of the following could be responsible for atherosclerosis and should be eliminated from diet for health reasons? A) butter B) olive oil C) liver and kidney organ meat D) butter, liver, and kidney organ meat

D

12) In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________. A) only altered primary structure B) only altered tertiary structure C) only altered quaternary structure D) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered

D

14) Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) Alzheimer's B) Parkinson's C) diabetes mellitus D) Alzheimer's and Parkinson's

D

14) Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum? A) in lysosomes B) in the Golgi apparatus C) in the nucleolus D) in mitochondria

D

15) Researchers investigating the mechanism of vesicular transport assembled a cell-free system that included microtubule tracks, vesicles, and ATP. However, they observed no movement of transport of vesicles in this system. What were they missing? A) an axon B) contractile microfilaments C) intermediate filaments D) motor proteins

D

18) Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to carry out which of the following processes? A) divide in two B) contract muscle fibers C) extend pseudopodia D) move vesicles within a cell

D

2) In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________. A) only altered primary structure B) only altered tertiary structure C) only altered quaternary structure D) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered

D

20) Which of the following categories includes all others in the list? A) disaccharide B) polysaccharide C) starch D) carbohydrate

D

26) To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first? A) pH B) density at room temperature C) heat of vaporization D) specific heat

D

30) Rank, from low to high, the pH of blood, stomach acid, and urine. A) blood, urine, and stomach acid B) stomach acid, blood, and urine C) urine, blood, stomach acid D) stomach acid, urine, blood

D

31) Which sentence best describes the logic of scientific inquiry? A) If I generate a testable hypothesis, tests and observations will support it. B) If my prediction is correct, it will lead to a testable hypothesis. C) If my observations are accurate, they will support my hypothesis. D) If my hypothesis is correct, I can expect certain test results.

D

33) Can the atomic mass of an element vary? A) No, it is fixed; otherwise a new element will be formed. B) Yes. Adding or losing electrons will substantially change the atomic mass. C) Yes. Adding or losing protons will change the atomic mass without forming a different element. D) Yes. Adding or losing neutrons will change the atomic mass without forming a different element.

D

36) How would acidification of seawater affect marine organisms? Acidification of seawater would ________. A) increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals B) decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals C) increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals D) decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals

D

38) Which of the following order is correct in terms of the hierarchy of the organization? A) Ecosystem → Biosphere → Population → Community → Organism B) Biosphere → Ecosystem → Population → Community → Organism C) Ecosystem → Community → Biosphere → Population → Organism D) Biosphere → Ecosystem →Community → Population → Organism

D

39) Use the following figure to answer the question. "A" is ________; "B" is ________. A) the most recent species to evolve on Earth; an ancestor of group "A" B) the most recent species to evolve on Earth; the last common ancestor of Archaea and Eukarya C) the common ancestor of all life; the common ancestor of Bacteria and Archaea D) the common ancestor of all life; the last common ancestor of Archaea and Eukarya

D

39) Which of the following statements correctly describes any chemical reaction that has reached equilibrium? A) The concentrations of products and reactants are equal. B) The reaction is now irreversible. C) Both forward and reverse reactions have halted. D) The rates of the forward and reverse reactions are equal.

D

5) Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) Alzheimer's B) Parkinson's C) diabetes mellitus D) Alzheimer's and Parkinson's

D

9) Saturated fats ________. A) are more common in plants than in animals B) have multiple double bonds in the carbon chains of their fatty acids C) are generally liquid at room temperature D) contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms

D

Refer to the following figure to answer the questions below. 37) What results from the chemical reaction in the illustration? The reactants have no charge. A) a cation with a net charge of +1 and an anion with a net charge of +1 B) a cation with a net charge of -1 and an anion with a net charge of -1 C) a cation with a net charge of -1 and an anion with a net charge of +1 D) a cation with a net charge of +1 and an anion with a net charge of -1

D

4) A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based just on this information, the organism is most likely ________. A) a nonmotile prokaryote B) a motile bacterium C) a motile archaea D) a nonmotile eukaryote E) a motile eukaryote

E