AP Bio Final
The following questions refer to an experiment that is set up to determine the relative volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two different temperatures. The change in volume is detected by using a respirometer over a given period of time. The data are given below. The rate of oxygen consumption in germinating pea seeds at 26ºC is A 0.05 mL / min B 0.25 mL / min C 0.50 mL / min D 0.75 mL / min E 1.00 mL / min
A 0.05 mL / min
The energy required to run the Calvin cycle reactions of photosynthesis comes from which two substances produced during the light-dependent reactions? A ATP and NADPH B ADP and PO4 C H+ and PO2 D O2 and CO2 E H2O and CO2
A ATP and NADPH
For following group of questions first study the description of the situation and diagrams and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. A student studied the effects of light intensity on oxygen production in green algae. The algae were suspended in water inside a sealed glass jar, and the jar was placed into a constant-temperature, lightproof box containing a light source. A probe was inserted into the jar to record the concentration of oxygen. The probe was connected to a recording device. The setup is shown below. The student decreased the intensity of the light hourly and recorded the corresponding changes in oxygen concentration. The graph below shows the results from the recording device. An increase in the rate of oxygen production by algae would be accompanied by a comparable increase in the rate of production of which of the following substances? A C6H12O6 B CO2 C CH4 D NH3 E H2O
A C6H12O6
The diagram below shows energy changes in a specific chemical reaction with and without the addition of an enzyme to the reaction. Which of the following questions can best be answered by the diagram? A Does the addition of an enzyme reduce the activation energy required for a reaction? B Does the addition of an enzyme result in the formation of covalent bonds? C Does the addition of an enzyme produce a greater amount of products? D Does the addition of an enzyme change the pathway for the reaction?
A Does the addition of an enzyme reduce the activation energy required for a reaction?
Which of the following statements is true regarding the movement of substances across cell membranes? A Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic. B Ions are able to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged. C Water is able to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are charged. D Water is unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged.
A Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic.
Two nutrient solutions are maintained at the same pH. Actively respiring mitochondria are isolated and placed into each of the two solutions. Oxygen gas is bubbled into one solution. The other solution is depleted of available oxygen. Which of the following best explains why ATP production is greater in the tube with oxygen than in the tube without oxygen? A The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen. B Electron transport is reduced in the absence of a plasma membrane. C In the absence of oxygen, oxidative phosphorylation produces more ATP than does fermentation. D In the presence of oxygen, glycolysis produces more ATP than in the absence of oxygen.
A The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen.
A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained. According to the results of this experiment, germination of tobacco seeds during the first week is A increased by exposure to light B unaffected by light intensity C prevented by paper towels D accelerated in green-leaved seedlings
A increased by exposure to light
Carbohydrate-synthesizing reactions of photosynthesis directly require A light B products of the light reactions C darkness D O2 and H2O E chlorophyll and CO2
A light
If 30% of the nucleotides in a single-stranded RNA molecule are adenine, then what percent are expected to be thymine? A: 0% B: 20% C: 30% D: 70%
A: 0%
A common test for liver function involves sprinkling sulfur powder onto a sample of urine (mostly water with dissolved bodily waste). Sulfur powder sprinkled on a sample from an individual with impaired liver function will sink because the urine contains a high level of bile salts, while the sulfur powder sprinkled on normal urine samples will float. Which of the following best explains why bile salts cause the sulfur powder to sink? A: Bile salts decrease the surface tension of the urine sample. B: Bile salts increase the water potential of the urine. C: Bile salts increase the density of the urine sample. D: Bile salts decrease the strength of the covalent bonds within a water molecule.
A: Bile salts decrease the surface tension of the urine sample.
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 best explains why a cell's plasma membrane is composed of two layers of phospholipids rather than just a single layer? A: Having two oppositely oriented layers of phospholipids allows only the hydrophilic heads to interact with water inside and outside of the cell. B: Having two oppositely oriented layers of phospholipids allows the hydrophilic heads to repel water both inside and outside of the cells. C: Having two identically oriented layers of phospholipids gives cells more protection from the exterior environment than just a single layer would. D: Having two identically oriented layers of phospholipids allows for the production of vacuoles while still maintaining a protective barrier.
A: Having two oppositely oriented layers of phospholipids allows only the hydrophilic heads to interact with water inside and outside of the cell.
Which of the following types of bonds is most likely responsible for the unusual base pairing shown in Figure 3 that results in the formation of a triplex DNA structure? A: Hydrogen B: Polar covalent C: Ionic D: Nonpolar covalent
A: Hydrogen
Which of the following statements is true regarding the movement of substances across cell membranes? A: Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic. B: Ions are able to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged. C: Water is able to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are charged. D: Water is unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged.
A: Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic.
A typical bag of fertilizer contains high levels of nitrogen, phosphorus, and potassium but trace amounts of magnesium and calcium. Which of the following best matches the fertilizer component with the molecule in which it will be incorporated by organisms in the area? A: Nitrogen will be incorporated into nucleic acids. B: Phosphorus will be incorporated into amino acids. C: Potassium will be incorporated into lipids. D: Magnesium will be incorporated into carbohydrates.
A: Nitrogen will be incorporated into nucleic acids.
Which of the following was the dependent variable in the researcher's study? A: The concentration of chlorophyll a B: The concentration of total nitrogen and phosphorus C: The slope of the trend line showing the rate of change D: The variance of the data points from the trend line
A: The concentration of chlorophyll a
Students in a class measured the mass of various living organisms. They then kept the organisms in the dark for 24 hours before remeasuring them. None of the organisms were provided with nutrients during the 24-hour period. The data are as follows. Which of the following is the best explanation for the pattern of change in mass of the organisms over time? A Water loss due to evaporation B Cellular respiration C The law of conservation of matter D Growth and reproduction
B Cellular respiration
A tissue culture of vertebrate muscle was provided with a constant excess supply of glucose under anaerobic conditions starting at time zero and the amounts of pyruvic acid and ATP produced were measured. The solid line in the graph above represents the pyruvic acid produced in moles per liter per minute. ATP levels were also found to be highest at points A and C, lowest at B and D. A second culture was set up under the same conditions, except that substance X was added, and the results are indicated by the dotted line. Which of the following is most likely to result if oxygen is added to the tissue culture? A Lactic acid formation will increase. B For each glucose molecule consumed, more ATP will be formed. C The levels of ATP produced will decrease. D Ethyl alcohol will be produced. E No change in the production of pyruvic acid will be observed.
B For each glucose molecule consumed, more ATP will be formed.
Which metabolic process is common to both aerobic cellular respiration and alcoholic fermentation? A Krebs cycle B Glycolysis C Electron transport chain D Conversion of pyruvic acid to acetyl CoA E Production of a proton gradient
B Glycolysis
Which of the following questions is most relevant to understanding the Calvin cycle? A How does chlorophyll capture light? B How is ATP used in the formation of 3-carbon carbohydrates? C How is NADP+ reduced to NADPH? D How is ATP produced in chemiosmosis?
B How is ATP used in the formation of 3-carbon carbohydrates?
For following group of questions first study the description of the situation and diagrams and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. A student studied the effects of light intensity on oxygen production in green algae. The algae were suspended in water inside a sealed glass jar, and the jar was placed into a constant-temperature, lightproof box containing a light source. A probe was inserted into the jar to record the concentration of oxygen. The probe was connected to a recording device. The setup is shown below. The student decreased the intensity of the light hourly and recorded the corresponding changes in oxygen concentration. The graph below shows the results from the recording device. Based on the data shown, changes in the light intensity resulted in changes in the rate of which of the following processes? A Excretion B Photosynthesis C Respiration D Translation E Transcription
B Photosynthesis
Which of the following can be used to determine the rate of enzyme-catalyzed reactions? A Rate of disappearance of the enzyme B Rate of disappearance of the substrate C Rate of disappearance of the product D Change in volume of the solution E Increase in activation energy
B Rate of disappearance of the substrate
Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data? A At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia. B The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases. C The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration. D In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.
B The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
Figure 1. Diagram of the electron transport chain and ATP synthase in the membrane of mitochondria On average, more ATP can be produced from an NADH molecule than can be produced from a molecule of FADH2. Based on Figure 1, which of the following best explains the difference in ATP production between these two molecules? A NADH contributes more electrons to the electron transport chain than FADH2 does and therefore provides more energy to pump protons. B The electrons of FADH2 are transferred through three complexes of the electron transport chain whereas those of NADH are transferred through all four complexes. C FADH2 contributes more protons to the mitochondrial matrix, which decreases the proton gradient. D The protons contributed by FADH2 are combined with O2 to make water and are not pumped across the membrane.
B The electrons of FADH2 are transferred through three complexes of the electron transport chain whereas those of NADH are transferred through all four complexes.
It is estimated that oxygen production first evolved in photosynthetic prokaryotes approximately 2.7 billion years ago. The first photosynthetic prokaryotes are presumed to be similar to today's cyanobacteria. Which of the following best supports the claim that photosynthetic prokaryotes were responsible for the oxygen in Earth's atmosphere? A The light reactions of photosynthesis split carbon dioxide into carbon and oxygen. B The light reactions of photosynthesis split water into hydrogen ions and oxygen. C The Calvin cycle splits glucose into carbon, hydrogen, and oxygen. D The Calvin cycle splits water into hydrogen ions and oxygen.
B The light reactions of photosynthesis split water into hydrogen ions and oxygen.
A student analyzed a viral genome and found that the genome had the following nucleotide composition. • 28% adenine • 20% thymine • 35% cytosine • 17% guanine Which of the following best describes the structure of the viral genome? A: Double-stranded DNA B: Single-stranded DNA C: Double-stranded RNA D: Single-stranded RNA
B: Single-stranded DNA
To study the actions of the enzyme catalase on hydrogen peroxide, students performed the following experiment. Catalase was extracted from potatoes by blending raw potatoes in a blender with cold distilled water. The filtrate was stored on ice. The following hydrogen peroxide solutions were made: 1 percent, 5 percent, 10 percent, and 15 percent. Filter paper disks were soaked in the catalase filtrate and dropped into beakers containing the various solutions. The activity of the enzyme was measured by the amount of time it took for the disks to float to the surface of the solution on the bubbles produced by the reaction. The following data were obtained. Which of the following best describes why ice was used during this experiment? A To increase the activity of the enzyme B To retard the breakdown of the catalase C To purge the solution of excess air trapped during blending D To slow the catalase molecules to increase the probability of contact with the hydrogen peroxide molecules E To increase the size of the active site on the enzyme
B To retard the breakdown of the catalase
A tissue culture of vertebrate muscle was provided with a constant excess supply of glucose under anaerobic conditions starting at time zero and the amounts of pyruvic acid and ATP produced were measured. The solid line in the graph above represents the pyruvic acid produced in moles per liter per minute. ATP levels were also found to be highest at points A and C, lowest at B and D. A second culture was set up under the same conditions, except that substance X was added, and the results are indicated by the dotted line. It is most reasonable to hypothesize that, in the breakdown of glucose, substance X is A an activator B an inhibitor C a substrate D a coenzyme E a cofactor
B an inhibitor
The carbon 'that makes up organic molecules in plants is derived directly from A combustion of fuels B carbon fixed in photosynthesis C carbon dioxide produced in respiration D carbon in the lithosphere E coal mines
B carbon fixed in photosynthesis
A scientist determined the rate of an enzyme-catalyzed reaction by measuring the amount of product formed over time. The following curve was generated from the data collected. The rate of the reaction could also be determined by A measuring the change in the amount of enzyme B measuring the change in the amount of substrate C measuring the change in salt concentration D adding more substrate E adding more enzyme
B measuring the change in the amount of substrate
During respiration, most ATP is formed as a direct result of the net movement of A potassium against a concentration gradient B protons down a concentration gradient C electrons against a concentration gradient D electrons through a channel E sodium ions into the cell
B protons down a concentration gradient
Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen synthase is one of the enzymes involved in converting carbohydrate monomers into polymers. Which of the following best explains the reactions of these enzymes? A: Amylase aids in the removal of a water molecule to break covalent bonds whereas glycogen synthase aids in the addition of a water molecule to form covalent bonds. B: Amylase aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds. C: Amylase aids in the addition of a water molecule to form covalent bonds whereas glycogen synthase aids in the removal of a water molecule to break covalent bonds. D: Amylase aids in the removal of a water molecule to form covalent bonds whereas glycogen synthase aids in the addition of a water molecule to break covalent bonds.
B: Amylase aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds.
Liver cells manufacture glycoproteins, while adipose cells store fat. Which of the following subcellular structures is likely to be more prominent in liver cells than in adipose cells? A: Nucleus B: Golgi apparatus C: Cytoskeleton D: Plasma membrane
B: Golgi apparatus
A researcher measured the temperature at which two different samples of double-stranded DNA denature (separate into single strands). Sample 11 denatured at a significantly lower temperature than sample 22 did. Based on the data, the researcher claims that the DNA in sample 22 is composed of a higher percentage of guanine and cytosine than the DNA in sample 11 is. Which of the following best supports the researcher's claim? A: The bonds between guanine and cytosine are covalent bonds, which require more energy to disrupt than those between adenine and thymine. B: Guanine-cytosine pairs denature at a higher temperature because they have more hydrogen bonds between them than adenine-thymine pairs do. C: Adenine-thymine pairs require less energy to separate because adenine and thymine are both single-ring bases. D: Guanine-cytosine pairs require more energy to separate because one is a purine and one is a pyrimidine.
B: Guanine-cytosine pairs denature at a higher temperature because they have more hydrogen bonds between them than adenine-thymine pairs do.
Which of the following describes the relationship between the amount of chlorophyll a in a water sample and the concentration of nitrogen in that sample? A: As the concentration of chlorophyll a increases, the concentration of nitrogen decreases. B: The concentrations of nitrogen and chlorophyll a are directly correlated. C: The concentrations of chlorophyll a and nitrogen increase throughout the year. D: There is no relationship between the concentrations of chlorophyll a and nitrogen.
B: The concentrations of nitrogen and chlorophyll a are directly correlated.
Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data? A: At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia. B: The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases. C: The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration. D: In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.
B: The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
Humans produce sweat as a cooling mechanism to maintain a stable internal temperature. Which of the following best explains how the properties of water contribute to this physiological process? A: The high specific heat capacity of water allows the body to absorb a large amount of excess heat energy. B: The high heat of vaporization of water allows the body to remove excess heat through a phase change of water from liquid to gas. C: The high surface tension of water contributes to the physical process by which water leaves the body. D: The high melting temperature of water allows the body to remove excess heat through a phase change of water from solid to liquid.
B: The high heat of vaporization of water allows the body to remove excess heat through a phase change of water from liquid to gas.
A mutation in the gene coding for a single-polypeptide enzyme results in the substitution of the amino acid serine, which has a polar R group, by the amino acid phenylalanine, which has a nonpolar R group. When researchers test the catalysis of the normal enzyme and the mutated enzyme, they find that the mutated enzyme has much lower activity than the normal enzyme does. Which of the following most likely explains how the amino acid substitution has resulted in decreased catalytic activity by the mutated enzyme? A: The substitution decreased the mass of the enzyme so that the mutated enzyme binds more weakly to the substrate than the normal enzyme does. B: The substitution altered the secondary and tertiary structure of the enzyme so that the mutated enzyme folds into a different shape than the normal enzyme does. C: The substitution caused many copies of the mutated enzyme to cluster together and compete for substrate to bind. D: The substitution caused the directionality of the enzyme to change such that the amino terminus of the normal enzyme has become the carboxy terminus of the mutated enzyme.
B: The substitution altered the secondary and tertiary structure of the enzyme so that the mutated enzyme folds into a different shape than the normal enzyme does.
Ultraviolet (UV) radiation can damage DNA by breaking weak bonds. Which of the following best explains how this occurs? A: UV radiation disrupts the double helix structure by breaking the covalent bonds between the nitrogenous base pairs. B: UV radiation disrupts the double helix structure by breaking the hydrogen bonds between the nitrogenous base pairs. C: UV radiation is able to break DNA strands in two by breaking covalent bonds between the sugar-phosphate backbone molecules. D: UV radiation is able to break DNA strands in two by breaking hydrogen bonds between the sugar-phosphate backbone molecules.
B: UV radiation disrupts the double helix structure by breaking the hydrogen bonds between the nitrogenous base pairs.
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
Students investigated the effect of light on the carbon cycle in aquatic ecosystems by performing the controlled experiment summarized below. The students placed equal amounts of water from a large aquarium in glass beakers. The students transferred aquatic plants from the aquarium to several of the beakers, and then they placed equal numbers of the beakers in the light or the dark. Similarly, the students transferred goldfish from the same aquarium to other beakers, and then they placed equal numbers of those beakers in the light or dark. Finally, the students placed an equal number of beakers containing water only in the light or dark. After exposing the samples to light or dark for one hour, the students recorded the pH. Carbon dioxide dissolved in water will lower the pH of an aqueous solution. In the experiment, the students used changes in pH to monitor changes in the amount of carbon dioxide in the water. For each treatment group, the students calculated the mean pH and standard error, as documented in the table below. Which of the following graphs is the most appropriate representation of the experimental results documented in the table? A; relative amounts of CO2 in a pie chart B: bar with margin of error C: line D: scatter chart
B: bar with margin of error
A scientist determined the rate of an enzyme-catalyzed reaction by measuring the amount of product formed over time. The following curve was generated from the data collected. What is the most likely explanation for the change in the slope of the line between 3 and 5 minutes? A The enzyme had denatured. B The enzyme had achieved its maximum velocity. C A large amount of the substrate had been consumed. D An allosteric inhibitor appeared. E There was a dramatic change in the pH.
C A large amount of the substrate had been consumed.
A tissue culture of vertebrate muscle was provided with a constant excess supply of glucose under anaerobic conditions starting at time zero and the amounts of pyruvic acid and ATP produced were measured. The solid line in the graph above represents the pyruvic acid produced in moles per liter per minute. ATP levels were also found to be highest at points A and C, lowest at B and D. A second culture was set up under the same conditions, except that substance X was added, and the results are indicated by the dotted line. Which of the following best accounts for the shape of the solid line between points A and D? A After ten minutes the cellular enzymes became ineffective. B Respiration became uncontrolled. C ATP acted as an allosteric inhibitor on one or more of the enzymes. D The measurements of pyruvic acid were unreliable. E The cells required more glucose than was being provided.
C ATP acted as an allosteric inhibitor on one or more of the enzymes.
Bacteriophages are viruses that infect bacteria. In an experiment, bacteriophages were labeled with either radioactive phosphorus or radioactive sulfur. The labeled bacteriophages were incubated with bacteria for a brief amount of time and then removed. The infected bacteria cells were found to contain significant amounts of radioactive phosphorus but not radioactive sulfur. Based on the results of the experiment, which of the following types of molecules did the bacteriophages most likely inject into the bacteria cells? A Simple carbohydrate B Amino acid C DNA D Polypeptide
C DNA
ATP serves as a common energy source for organisms because A it is the smallest energy molecule B it stores the least energy of any energy source C its energy can be easily transferred to do cellular work D it is extremely stable and can be stored in the cell for long periods of time E traces of it have been found in fossils of ancient organisms dating back to the beginning of life on Earth
C its energy can be easily transferred to do cellular work
The following questions refer to the following information and graph. The data presented in the figure below are measurements of the rate of oxygen consumption at differing body masses in a species of fish. Each point represents measurements from a different fish. Measurements were taken at different temperatures. (○= 10°C,●= 15°C, □= 20°C, ■= 25°C.) The fact that each line on the graph rises from left to right means that A higher temperatures produce higher rates of metabolism B there were more large fish in the samples taken at high temperatures C larger fish consume more oxygen than smaller fish at all four temperatures D when measurements are taken for larger fish late in the day, observed values are higher E larger fish prefer to live at higher temperatures than do smaller fish
C larger fish consume more oxygen than smaller fish at all four temperatures
A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained. Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because A yellow-leaved seedlings were unable to absorb water from the paper towels B taller green-leaved seedlings blocked the light and prevented photosynthesis C yellow-leaved seedlings were unable to convert light energy to chemical energy D a higher rate of respiration in yellow-leaved seedlings depleted their stored nutrients
C yellow-leaved seedlings were unable to convert light energy to chemical energy
Which of the following best describes the hydrolysis of carbohydrates? A: The removal of a water molecule breaks a covalent bond between sugar monomers. B: The removal of a water molecule forms a covalent bond between sugar monomers. C: The addition of a water molecule breaks a covalent bond between sugar monomers. D: The addition of a water molecule forms a covalent bond between sugar monomers.
C: The addition of a water molecule breaks a covalent bond between sugar monomers.
Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. Which of the following best summarizes an advantage of eukaryotic cells having internal membranes? A: Eukaryotic cells are able to reproduce faster because of the presence of organelles. B: Some organelles, such as mitochondria and chloroplasts, are similar to prokaryotic cells in structure. C: Organelles isolate specific reactions, increasing metabolic efficiency. D: Compartmentalization leads to a higher mutation rate in DNA, which leads to more new species.
C: Organelles isolate specific reactions, increasing metabolic efficiency.
Bacteriophages are viruses that infect bacteria. In an experiment, bacteriophages were labeled with either radioactive phosphorus or radioactive sulfur. The labeled bacteriophages were incubated with bacteria for a brief amount of time and then removed. The infected bacteria cells were found to contain significant amounts of radioactive phosphorus but not radioactive sulfur. Based on the results of the experiment, which of the following types of molecules did the bacteriophages most likely inject into the bacteria cells? A: Simple carbohydrate B: Amino acid C: DNA D: Polypeptide
C: DNA
Which of the following best describes the process by which gas from the atmosphere is obtained by plants and used to build lipids? A: Gas is fixed by plants as part of the sulfur cycle. B: Gas is fixed by plants as part of the nitrogen cycle. C: Gas is directly obtained by plants as part of the carbon cycle. D: Gas is directly obtained by plants as part of the magnesium cycle.
C: Gas is directly obtained by plants as part of the carbon cycle.
Which of the following is responsible for the cohesive property of water? A: Hydrogen bonds between the oxygen atoms of two adjacent water molecules B: Covalent bonds between the hydrogen atoms of two adjacent water molecules C: Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule D: Covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule E: Hydrogen bonds between water molecules and other types of molecules
C: Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule
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 amino acid in Figure 1 is found in a region of a polypeptide that folds away from water. Which part of the amino acid most likely contributes to the hydrophobic behavior of this region of the polypeptide? A: Amine (NH2) group B: Carboxyl (COOH) group C: Methyl (CH3) group D: Hydrogen (H) atom
C: Methyl (CH3) group
Used to carry the genetic code A: Proteins B: Carbohydrates C: Nucleic acids D: Lipids E: Steroids
C: Nucleic acids
The figure above represents a rough endoplasmic reticulum. Which of the following best describes the role of the structure labeled Y, ribosomes? A: Structure Y contributes the raw materials required for the synthesis of proteins. B: Structure Y packages proteins for export from the cell. C: Structure Y is the location where proteins are synthesized. D: Structure Y contains enzymes that cut and activate proteins.
C: Structure Y is the location where proteins are synthesized.
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.
A feature of organic compounds NOT found in inorganic compounds is the presence of A: ionizing chemical groups B: electrons C: carbon atoms covalently bonded to each other D: oxygen E: hydrogen bonds
C: carbon atoms covalently bonded to each other
Evolved from a photoautotrophic prokaryote
Chloroplast
For following group of questions first study the description of the situation and diagrams and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. A student studied the effects of light intensity on oxygen production in green algae. The algae were suspended in water inside a sealed glass jar, and the jar was placed into a constant-temperature, lightproof box containing a light source. A probe was inserted into the jar to record the concentration of oxygen. The probe was connected to a recording device. The setup is shown below. The student decreased the intensity of the light hourly and recorded the corresponding changes in oxygen concentration. The graph below shows the results from the recording device. The rate of oxygen production equaled the rate of oxygen consumption during which of the following time periods? A G to H B H to I C I to J D J to K E G to K
D J to K
To study the actions of the enzyme catalase on hydrogen peroxide, students performed the following experiment. Catalase was extracted from potatoes by blending raw potatoes in a blender with cold distilled water. The filtrate was stored on ice. The following hydrogen peroxide solutions were made: 1 percent, 5 percent, 10 percent, and 15 percent. Filter paper disks were soaked in the catalase filtrate and dropped into beakers containing the various solutions. The activity of the enzyme was measured by the amount of time it took for the disks to float to the surface of the solution on the bubbles produced by the reaction. The following data were obtained. Which of the following best describes why the disks rose to the surface faster in the more concentrated hydrogen peroxide solutions? A There was more enzyme present in the more concentrated solutions. B A greater amount of heat was generated in the more concentrated solutions. C The more concentrated solutions lowered the activation energy of the reaction. D The higher substrate concentrations in the more concentrated solutions speeded the reaction. E The density of the water was lower in the more concentrated solutions.
D The higher substrate concentrations in the more concentrated solutions speeded the reaction.
A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water. If ADH secretion is inhibited, which of the following would initially result? A The number of aquaporins would increase in response to the inhibition of ADH. B The person would decrease oral water intake to compensate for the inhibition of ADH. C Blood filtration would increase to compensate for the lack of aquaporins. D The person would produce greater amounts of dilute urine.
D The person would produce greater amounts of dilute urine.
A sample of human blood was placed in a test tube containing a physiological saline solution (0.9% sodium chloride). This type of solution is often used intravenously to quickly rehydrate patients. A drop of the blood from the test tube was placed on a slide and red blood cells (RBCs) were observed under a microscope. Three possible outcomes are diagrammed below. Which of the following best predicts which diagrammed microscope view the laboratory worker would see and best explains why? A View 1 because RBC membranes are freely permeable to water B View 2 because the RBCs use energy to allow sodium entry and to pump water out C View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells D View 3 because the sodium-potassium pumps in the RBC membranes use energy to keep the sodium out but allow water to freely flow into the cells
D View 3 because the sodium-potassium pumps in the RBC membranes use energy to keep the sodium out but allow water to freely flow into the cells
According to the chemiosmotic theory (chemiosmotic coupling), the energy required to move protons from the mitochondrial matrix to the intermembrane space against a concentration gradient comes most directly from A photons of red or blue light B the hydrolysis of ATP C the breakdown of high-energy fatty acids in the mitochondrial matrix D electrons flowing along the electron transport chain E substrate-level phosphorylation
D electrons flowing along the electron transport chain
Which of the following best describes the function of the coenzymes NAD+ and FAD in eukaryotic cellular respiration? A They participate in hydrolysis reactions by accepting protons from water molecules. B They participate directly in the phosphorylation of ADP to ATP. C They serve as final electron acceptors in the electron transport chain. D They aid vitamins such as niacin in the breakdown of glucose. E They accept electrons during oxidation-reduction reactions.
E They accept electrons during oxidation-reductionreactions.
Which of the following best explains how higher concentrations of nitrogen and phosphorus contribute to eutrophication? A: An increase in the population of algae results in more nitrogen and phosphorus in the water, causing severe eutrophication. B: Both bacteria and algae require nitrogen and phosphorus, so the algae must grow faster to compete with bacteria. C: Nitrogen and phosphorus stimulate oxidative phosphorylation, which consumes the available oxygen in the water. D: Algae require nitrogen and phosphorus to build macromolecules, so higher concentrations of these nutrients can result in algal blooms.
D: Algae require nitrogen and phosphorus to build macromolecules, so higher concentrations of these nutrients can result in algal blooms.
Which of the following groups of cellular components are found in eukaryotic cells but not prokaryotic cells? A: Ribosomes, a nucleus, and chloroplasts B: Circular chromosomes, mitochondria, and an endoplasmic reticulum C: A nucleus, ribosomes, and cell walls D: An endoplasmic reticulum, mitochondria, and a nucleus
D: An endoplasmic reticulum, mitochondria, and a nucleus
Which of the following is most directly responsible for water's unique properties? A: It contains oxygen atoms. B: It contains hydrogen atoms. C: It is an ionic compound. D: It forms hydrogen bonds. E: It is nonpolar.
D: It forms hydrogen bonds.
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.
A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water. If ADH secretion is inhibited, which of the following would initially result? A: The number of aquaporins would increase in response to the inhibition of ADH. B: The person would decrease oral water intake to compensate for the inhibition of ADH. C: Blood filtration would increase to compensate for the lack of aquaporins. D: The person would produce greater amounts of dilute urine.
D: The person would produce greater amounts of dilute urine.
The diagram shows how water can adhere to the xylem in the stems of plants, which contributes to water movement in the plant. Which of the following best explains how water is able to move upward from the roots of a plant, through its xylem in the stem, and out to the leaves? A: Water is polar, and the walls of the xylem are nonpolar. Water molecules have the ability to form hydrogen bonds with one another but not with the xylem walls. B: Water is nonpolar, and the walls of the xylem are polar. Water molecules are able to form hydrogen bonds with the xylem walls, and they are pulled up the xylem. C: Water and the xylem are both nonpolar. Water molecules have the ability to form hydrogen bonds with one another but not with the xylem walls. D: Water and the xylem are both polar. Water molecules have the ability to form hydrogen bonds with each other and with the walls of the xylem.
D: Water and the xylem are both polar. Water molecules have the ability to form hydrogen bonds with each other and with the walls of the xylem.
Which of the following statements about mitochondrial chemiosmosis is NOT true? A A proton gradient is established across the inner membrane of the mitochondrion. B The potential energy released from the mitochondrial proton gradient is used to produce ATP. C The mitochondrial proton gradient provides energy for muscle contraction. D Proteins embedded in the inner mitochondrial membrane play an important role in ATP synthesis. E Heat energy is required to establish the electron transport chain.
E Heat energy is required to establish the electron transport chain.
The following questions refer to an experiment that is set up to determine the relative volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two different temperatures. The change in volume is detected by using a respirometer over a given period of time. The data are given below. Which of the following conclusions is best supported by the data? A Nongerminating pea seeds have a higher rate of respiration than germinating pea seeds do. B Light is required for pea seed germination. C In the nongerminating pea seeds, oxygen consumption is directly proportional to oxygen concentration. D Less carbon dioxide is produced by germinating pea seeds at 26ºC than at 10ºC. E In pea seeds an increase in temperature results in an increase in oxygen consumption.
E In pea seeds an increase in temperature results in an increase in oxygen consumption.
Which of the following is an important difference between light-dependent and light-independent reactions of photosynthesis? A The light-dependent reactions occur only during the day; the light-independent reactions occur only during the night. B The light-dependent reactions occur in the cytoplasm; the light-independent reactions occur in chloroplasts. C The light-dependent reactions utilize CO2 and H2O; the light-independent reactions produce CO2 and H2O. D The light-dependent reactions depend on the presence of both photosystems I and II; the light-independent reactions require only photosystem I. E The light-dependent reactions produce ATP and NADPH; the light-independent reactions use energy stored in ATP and NADPH.
E The light-dependent reactions produce ATP and NADPH; the light-independent reactions use energy stored in ATP and NADPH.
To study the actions of the enzyme catalase on hydrogen peroxide, students performed the following experiment. Catalase was extracted from potatoes by blending raw potatoes in a blender with cold distilled water. The filtrate was stored on ice. The following hydrogen peroxide solutions were made: 1 percent, 5 percent, 10 percent, and 15 percent. Filter paper disks were soaked in the catalase filtrate and dropped into beakers containing the various solutions. The activity of the enzyme was measured by the amount of time it took for the disks to float to the surface of the solution on the bubbles produced by the reaction. The following data were obtained. If the potato solution was boiled for 10 minutes and cooled for 10 minutes before being tested, the average time for the disks to float to the surface of the hydrogen peroxide solution would be A less than 1 second B 5 seconds C 10 seconds D 30 seconds E more than 30 seconds
E more than 30 seconds
The synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct? A: ATP B: Oxygen C: Carbon dioxide D: Urea E: Water
E: Water
Site of transport of materials into and out of the cell
cell membrane
site of glucose synthesis
chloroplast
Site of modification and packaging of proteins and lipids prior to export from the cell
golgi apparatus
Site of conversion of chemical energy of glucose to ATP
mitochondria
