1. Which of the following is not a theme that unifies biology?
A) interaction with the environment
B) emergent properties
E) structure and function
3. Identical heat lamps are arranged to shine on identical containers of water and methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?
6. In order to understand the chemical basis of inheritance, one must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology?
B) emergent properties
D) the cell theory
E) feedback regulation
7. Which of these is reflective of the hierarchical organization of life from most to least inclusive?
A) kingdom, order, family, phylum, class, genus, species
B) phylum, class, order, kingdom, family, genus, species
C) kingdom, phylum, class, order, family, genus, species
D) genus, species, kingdom, phylum, class, order, family
E) class, order, kingdom, phylum, family, genus, species
8. Evolution occurs at what level of organization?
9. Which of these classes of biological molecules does NOT include polymers?
D) nucleic acids
10. Succinate dehydrogenase catalyzes the conversion of succinate to
fumarate. The reaction is inhibited by malonic acid, which resembles
succinate but cannot be acted upon by succinate dehydrogenase.
Increasing the ratio of succinate to malonic acid reduces the
inhibitory effect of malonic acid.
Based on this information, which of the following is correct?
A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate.
B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate.
C) Succinate is the substrate, and fumarate is the product.
D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor.
E) Malonic acid is the product, and fumarate is a competitive inhibitor.
11. Succinate dehydrogenase catalyzes the conversion of succinate to
fumarate. The reaction is inhibited by malonic acid, which resembles
succinate but cannot be acted upon by succinate dehydrogenase.
Increasing the ratio of succinate to malonic acid reduces the
inhibitory effect of malonic acid.
What is malonic acid's role with respect to succinate dehydrogenase?
A) It is a competitive inhibitor.
B) It blocks the binding of fumarate.
C) It is a noncompetitive inhibitor.
D) It is able to bind to succinate.
E) It is an allosteric regulator.
A series of enzymes catalyze the reaction 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.
What is substance X?
A) a coenzyme
B) an allosteric inhibitor
C) a substrate
D) an intermediate
E) the product
14. A series of enzymes catalyze the reaction 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) a coenzyme.
B) an allosteric inhibitor.
C) the substrate.
D) an intermediate.
E) a competitive inhibitor.
15. Which of the following is true of metabolism in its entirety in all organisms?
A) Metabolism depends on a constant supply of energy from food.
B) Metabolism depends on an organism's adequate hydration.
C) Metabolism uses all of an organism's resources.
D) Metabolism consists of all the energy transformation reactions in an organism.
E) Metabolism manages the increase of entropy in an organism.
16. Which of the following statements is a logical consequence of the second law of thermodynamics?
A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe.
B) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe.
C) Every energy transfer requires activation energy from the environment.
D) Every chemical reaction must increase the total entropy of the universe.
E) Energy can be transferred or transformed, but it cannot be created or destroyed.
17. 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) 0 kcal/mol
D) +20 kcal/mol
E) +40 kcal/mol
18. 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.
E) All structural levels are equally affected.
19. According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?
A) The binding of the substrate depends on the shape of the active site.
B) Some enzymes change their structure when activators bind to the enzyme.
C) A competitive inhibitor can outcompete the substrate for the active site.
D) The binding of the substrate changes the shape of the enzyme's active site.
E) The active site creates a microenvironment ideal for the reaction.
20. The molecular formula for glucose is C₆H₁2O₆. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
21. Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
22. The tertiary structure of a protein is the _____.
A) order in which amino acids are joined in a polypeptide chain
B) unique three-dimensional shape of the fully folded polypeptide
C) organization of a polypeptide chain into an α-helix or β-pleated sheet
D) overall protein structure resulting from the aggregation of two or more polypeptide subunits
24. Which statement best explains the connection between the sequence and subcomponents of a protein and its properties?
A) The unique shape of a protein provides that protein with the ability to carry on several different functions.
B) A renatured protein will not function properly since proteins cannot regain their original sequence of amino acids after denaturation.
C) A denatured protein will continue to have the same function since only the structure of the protein is affected.
D) The specific shape of a protein is naturally known to the original sequence of amino acids so the protein will function properly after renaturation.
25. The accompanying table represents the results of an experiment where the effects of pH buffers on an enzyme found in saliva (amylase) were studied. A spectrophotometer set at 500nm was used to measure absorbance at the various pH levels every 20 sec for 2 min. The higher absorbance values would indicate greater enzyme activity. All experiments were conducted at the same temperature.
Which statement correctly identifies the result that the optimum pH for amylase function is 7?
A) The pH with the lowest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
B) The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
C) At pH 9, the enzyme is denatured and will lose its function, but not its structure.
D) At pH 4, the structure of the enzyme will be altered, and the enzyme would not be able to catalyze the reaction.
27. All of the following occur during mitosis except
A) the formation of a spindle.
B) the disappearance of the nucleolus.
C) the synthesis of DNA
D) the uncoupling of chromatids at the centromere.
E) the condensing of chromosomes.
28. If there are 20 centromeres in a cell, how many chromosomes are there?
29. Triggers the cell's passage past the G2 checkpoint into mitosis.
C) protein kinase
30. Which of the following (are) primarily responsible for cytokinesis in plant cells?
A) Actin and myosin
B) centrioles and basal bodies
C) cyclin-dependent kinases
E) Golgi-derived vesicles
31. Plasma membrane
A) a feature of all cells
B) found in prokaryotic cells only
C) found in eukaryotic cells only
D) found in plant cells only
E) found in animal cells only
32. Of the following, what do both mitochondria and chloroplasts have in common?
A) ATP is produced.
B) DNA is present.
C) Ribosomes are present.
D) Only B and C are correct.
E) A, B, and C are correct.
33. What part of the extracellular matrix is thought to participate in anchoring the plasma membrane to the cytoskeleton of animal cell?
A) the nucleus.
C) DNA and RNA.
E) lipoproteins in the membrane
34. Density-dependent inhibition is explained by which of the following?
A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors.
B) As cells become more numerous, the amount of required growth factors and nutrients per cell becomes insufficient to allow for cell growth.
C) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor.
D) As cells become more numerous, more and more of them enter the S phase of the cell cycle.
E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism.
35. Which of the following does not occur during mitosis?
A) replication of the DNA
B) packaging of the chromosomes
C) separation of sister chromatids
D) separation of the centromeres
E) spindle formation
36. When biologists wish to study the internal ultrastructure of cells, they most likely would use
A) a light microscope.
B) a scanning electron microscope.
C) a transmission electronic microscope.
D) A and C only
E) A, B, and C
38. Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with
A) a cell with high concentrations of actin and myosin
B) a cell with a single large nucleus
C) two abnormally small nuclei.
D) two normal nuclei
E) two nuclei but with half the amount of DNA.
39. Which of the following is true concerning cancer cells?
A) When they stop dividing, they do so at random points in the cell cycle.
B) They do not exhibit density-dependent inhibition when growing in culture.
C) They have escaped from cell cycle controls.
D) B and C are true.
E) A, B, and C are true.
40. Which of the following is a major difference between prokaryotic cells and eukaryotic cells?
A) Prokaryotes have cells while eukaryotes do not.
B) Eukaryotic cells have more intracellular organelles than prokaryotes.
C) Prokaryotes are not able to carry out aerobic respiration, relying instead on anaerobic metabolism.
D) Prokaryotes are generally larger than eukaryotes.
43. Which of the following is a protein maintained at steady levels throughout the cell cycle that requires cyclin to become catalytically active?
44. Density-dependent inhibition is a phenomenon in which crowded cells stop dividing at some optimal density and location. This phenomenon involves binding of a cell-surface protein to its counterpart on an adjoining cell's surface. A growth inhibiting signal is sent to both cells, preventing them from dividing. Certain external physical factors can affect this inhibition mechanism.
Select the statement that makes a correct prediction about natural phenomena that could occur during the cell cycle to prevent cell growth.
A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to allow cell growth.
B) As cells become more numerous, the protein kinases they produce begin to compete with each other until only one cell has the proteins necessary for growth.
C) As cells become more numerous, the amount of required growth factors and nutrients per cell becomes insufficient to allow for cell growth.
D) As cells become more numerous, more and more of them enter the synthesis part of the cell cycle and duplicate DNA to inhibit cell growth.
45. Most enzymatic hydrolysis of the macromolecules in food occurs in the
D) large intestine
E) small intestine
46. All of the following are mechanisms of thermoregulation in terrestrial mammals except
A) changing the rate of evaporative heat loss.
B) changing the rate of heat loss by vasodilation and vasoconstriction.
C) changing the rate of metabolic heat production.
D) changing the rate of heat exchange by conforming to environmental temperatures.
E) relocating to cool areas when too hot, or to warm areas when too cold.
47. To leave the digestive tract into the body, a substance must cross a cell membrane. During which stage of food processing does this take place?
48. What is the functional unit of nervous tissue?
A) cell body
49. How do animal structures well suited to specific functions come about?
A) An animal that needs a new function will develop a new structure to provide it.
B) Animals invent structural designs that enhance their functions.
C) Mutations arise to provide required structures for survival in a particular environment.
D) Animals continually improve their structures in order to improve their functions.
E) Natural selection favors the most functional structures for a particular environment.
50. You discover a new species of bacteria that grows in aquatic environments with high salt levels. While studying these bacteria, you note that their internal environment is similar to the salt concentrations in their surroundings. You also discover that the internal salt concentrations of the bacteria change as the salt concentration in their environment changes. The new species can tolerate small changes in this way, but dies from large changes because it has no mechanism from altering its own internal salt levels. What type of homeostatic mechanism is this species using to regulate its internal salt levels?
51. Which one of the following has a shape most like a diploblatic animal with a gastrovascular cavity?
A) a drinking straw
B) a vase
C) a garden hose
D) an umbrella
E) a baseball bat
52. Hormones that affect the pancreas include
E) both C and D
53. The source of trypsinogen and chymotrypsin is the
54. In its travel through the human body, blood usually continues on from capillaries to enter
D) other capillaries
55. A patient with a blood pressure of 120/75, a pulse rate of 70 beats/minute a stroke volume of 70 mL/beat (milliliters per beat), and a respiratory rate of 25 breaths/minute will have a cardiac output of
A) 1750 mL/minute
B) 4900 mL/minute
C) 2800 mL/minute
D) 1000 mL/minute
56. What occurs during systole?
A) Oxygen-rich blood is pumped to the lungs.
B) Oxygen-poor blood from all body regions except the lungs flows into the right atrium.
C) The atrioventricular valves suddenly open.
D) The heart muscle tissues contract.
E) all of these
57. Which cell produces the fibrin used in blood clots?
A) occurs at the beginning of the capillary bed.
B) occurs at the end of the capillary bed.
C) is the movement of materials through capillaries.
D) is the movement of components of the interstitial fluid into a capillary bed
E) is the movement of components of the interstitial fluid into a capillary bed and occurs at the end of the capillary bed.
59. The human heart
A) will contract as a result of stimuli from the sinoatrial node.
B) is independent of all nervous control.
C) contracts only as a result of nerve stimulation from the central nervous system.
D) is activated primarily through the autonomic nervous system.
E) pulse is primarily under the control of the atrioventricular node.
60. Which of the following events would be predicted by the Bohr shift effect as the amount of carbon dioxide released from your tissues into the blood capillaries increases? The amount of oxygen in
A) arterial blood would increase.
B) venous blood would decrease.
C) arterial blood would decrease.
D) venous blood would increase.
61. Exchange across a membrane requires
A) moisture and pressure gradient, only
C) pressure gradients.
D) transport proteins.
E) moisture, pressure gradients, and transport proteins.
62. Oxygenated blood enters the heart the heart via this structure.
A) right atrium
B) left atrium
C) left ventricle
D) right ventricle
63. One of the waste products that accumulates during cellular functions is carbon dioxide. It is removed via the respiratory system. What is another waste product that accumulates during normal physiological functions in vertebrates?
II) uric acid
A) only I and III
B) only II and III
C) only I and II
D) I, II, and III
64. A patient who has a high level of mast cell activity, dilation of blood vessels, and acute drop in blood pressure is likely suffering from
A) an autoimmune disease
B) a typical skin allergy (contact dermatitis) that can be treated by antihistamines
C) and organ transplant, such as the skin graft
D) anaphylactic shock immediately following exposure to an allergen
65. In a humoral antibody-mediated immune response, specific B cells are stimulated by helper T cells to transform into plasma cells that secrete antibodies. What would be an important feature added to B cells in this transition process?
A) An increased cell size with more plasma membrane to increase the surface to volume ratio of the cell.
B) Duplication of specific gene sequences for the appropriate antibody.
C) Increased rough endoplasmic reticulum in order to have the surface area needed for antibody production.
D) Duplication of lysosomes in order to store the antibodies before transport.
66. The following steps referred to various stages in transmission a chemical synapse.
1. Neurotransmitter bind with receptors associated with the postsynaptic membrane.
2. Calcium ions rushed into neurons cytoplasm.
3. An action potential depolarizes the membrane of the presynaptic axon terminal.
4. The ligand-gated ion channels open.
5. The synaptic vesicles release neurotransmitter into the synaptic cleft.
Which sequence of events is correct?
67. Which of the following is the correct sequence that describes the excitation and contraction of the skeletal muscle fiber?
1. Tropomyosin shifts and unlocks the cross-bridge binding sites.
2. Calcium is released and binds to the troponin complex.
3. Transverse tubules depolarize the sarcoplasmic reticulum.
4. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP.
5. An action potential in a motor neuron causes and axon to release acetylcholine, which depolarizes of muscle cell membrane.
68. For a neuron with an initial membrane potential at -70 mV, an increase of the movement of potassium ions out of that neurons cytoplasm result in the
A) depolarization of the neuron
B) hyperpolarization of the neuron
C) replacement of potassium ions with sodium ions
D) replacement of potassium ions with calcium ions
69. "Marine cone snails from the genus Conus are estimated to consist of up to 700 species. These predatory molluscs have devised an efficient venom apparatus that allows them to successfully capture polychaete worms, other molluscs, or in some cases fish as their primary food sources. ... conotoxins from Australian species of Conus ... have the capacity to inhibit specifically the nicotinic acetylcholine receptors in higher animals." (B. G. Livett, K. R. Gayler, and Z. Khalil. 2004. Drugs from the sea: Conopeptides as potential therapeutics. Current Medicinal Chemistry 11:1715-23.)
Refer to the paragraph above on the venom of marine core snails. This particular conotoxin inhibits acetylcholine receptors that are located.
A) along the motor neuron axon
B) on motor neuron dendrites
C) on the presynaptic membrane of the neuromuscular junction
D) on the postsynaptic membrane, on the muscle cell
70. Acetylcholine released into the junction between motor not in a skeletal muscle binds to a sodium channel and opens it. This is an example of
A) a voltage-gated potassium channel
B) a ligand-gated sodium channel
C) a second messenger gated sodium channel
D) a chemical that inhibits action potential
71. When action potential from a motor neuron arrives at the neuromuscular junction (NMJ), series of events occurs that leads to muscle contraction. Which of the following events will occur last (is, after all of the others)?
A) acetylcholine (ACh) release
B) conformational change in troponin
C) depolarization of the muscle cell
D) release of Ca2+ from the sarcoplasmic reticulum
72. Two centrosomes are arranged at opposite poles of the cell.
73. What are enzymes called that control the activities of other proteins by phosphorylating them?
74. Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
75. In function, the plant cell structure that is analogous to an animal cell's cleavage furrow is the
C) cell plate
D) spindle apparatus
76. A particular cell has half as much DNA as some of the other cells in a mitotically active tissue. The cell in question is most likely in
77. 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 the cell-cell interaction (cell 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) One cell functioned as the nucleus for each organism, thereby attracting only cells of the same pigment
B) The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment.
C) The molecule responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge
D) The two species of sponge had different enzymes that functioned in the reassembly process.
78. When a plant cell such as one from a rose stem, is submerged in a very hypotonic solution, what is likely to occur?
A) The cell will become turgid.
B) The cell will burst.
C) Plasmolysis will shrink the interior.
D) The cell will become flaccid.
79. In what ways do the membranes of a eukaryotic cell vary?
A) Only certain membranes of the cell are selectively permeable.
B) Certain proteins are unique to each membrane.
C) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.
D) Phospholipids are found only in certain membranes.
80. You have a planar bilayer with equal amounts of saturated and unsaturated phospholipids. After testing the permeability of this membrane to glucose, you increase the proportion of unsaturated phospholipids in the bilayer. What will happen to the membrane's permeability to glucose?
A) Permeability to glucose will increase.
B) Permeability to glucose will decrease.
C) Permeability to glucose will stay the same.
D) You cannot predict the outcome. You simply have to make the measurement.
81. Three lab groups carried out an experiment to identify the correct molarities for five 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. Each data entry represents the average of 3 sample replications of 1 cm3 sweet potato cubes expressed as percent change in mass after an overnight (24 hr) soak in the unknown solutions. From the data given, which statement most accurately describes what is occurring in response to a particular unknown solution.
A) Unknown solution E contains the highest concentration of sucrose and the change in mass is due to the active transport of sucrose into the cell in exchange for water molecules.
B) Osmosis of water molecules from unknown solution A likely caused the increase in mass observed.
C) Passive transport of sucrose out of the potato cells explains the change in mass observed for unknown solution F.
D) Unknown solution C represents a sucrose molarity slightly lower than the molarity of sweet potato cells, thus water is transported out of the cells.
82. 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.
Question: Refer to the figure. Initially, in terms of tonicity, the solution in side A with respect to the solution in side B is _____.
83. 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.
Question: Refer to the figure. After the system reaches equilibrium, what changes are observed?
A) The molarity of sucrose is higher than that of glucose on side A.
B) The water level is higher in side A than in side B.
C) The water level is unchanged.
D) The water level is higher in side B than in side A.
84. 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..
Question: Refer to the figure. If you examine side A after three days, you should find _____.
A) a decrease in the concentration of NaCl and glucose and an increase in the water level
B) a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose
C) a decrease in the concentration of NaCl and a decrease in the water level
D) no change in the concentration of NaCl and glucose and an increase in the water level
85. 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..
Question: Refer to the figure. At the beginning of the experiment,
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.
86. Five dialysis bags constructed of membrane, which 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.
Question: Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes?
A) A and B
D) D and E
87. Five dialysis bags constructed of membrane, which 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.
Question: Which line in the graph represents the bag with the highest initial concentration of sucrose?
88. Five dialysis bags constructed of membrane, which 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.
Question: 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?