AP Bio- Exam Study Guide

The reactions of glycolysis occur in the A cytosol B nucleus C matrix of the mitochondrion D membranes of the mitochondrion E stroma of the chloroplast

A cytosol

A small protein is composed of 110 amino acids linked together in a chain. As shown in Figure 1, the first and last five amino acids in the chain are hydrophobic (have nonpolar and uncharged R-groups), whereas the remaining 100 amino acids are hydrophilic (have charged or polar R-groups). The nature of the R-group determines if the amino acid is hydrophobic or hydrophilic. A mutation results in the production of a version of the small protein that is only 105 amino acids long, as shown in Figure 2. Five of the hydrophobic amino acids are missing from one end of the chain. Which of the following best depicts the tertiary structures of the two proteins in water? The diagrams in the options are not drawn to the same scale as those in Figure 1 and Figure 2. A B C D

A

If 30% of the nucleotides in a single-stranded RNA molecule are adenine, then what percent are expected to be thymine? A 0%0% B 20%20% C 30%30% D 70%

A 0%

Directions: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. (A) Glysolysis(B) Krebs cycle (citric acid cycle)(C) Calvin cycle (light-independent reactions of photosynthesis)(D) Light-dependent reactions of photosynthesis(E) Chemiosmosis Process in which sugar is oxidized to pyruvic acid A A B B C C D D E E

A A

An experiment to measure the rate of respiration in crickets and mice at 10o C and 25o C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trials, and the following data were obtained. During aerobic cellular respiration, oxygen gas is consumed at the same rate as carbon dioxide gas is produced. In order to provide accurate volumetric measurements of oxygen gas consumption, the experimental setup should include which of the following? A A substance that removes carbon dioxide gas B A plant to produce oxygen C A glucose reserve D A valve to release excess water

A A substance that removes carbon dioxide gas

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

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?

All eukaryotic cells contain at least one Golgi complex, typically located in the cytoplasm and near the endoplasmic reticulum. Which of the following best describes a process that occurs within the Golgi complex? A Enzymatic modification of newly synthesized integral membrane proteins B Synthesis of cytosolic proteins based on the nucleotide sequences of mRNAsmRNAs C Degradation of proteins by hydrolytic enzymes contained within the complex D Synthesis of various types of lipids

A Enzymatic modification of newly synthesized integral membrane proteins

Figure 1. Reaction catalyzed by phosphofructokinase (PFK) during glycolysis Phosphofructokinase (PFK) is an enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate during glycolysis, as represented in Figure 1. PFK can be allosterically inhibited by ATP at high concentrations. Which of the following is the benefit of regulating glycolysis by the concentration of ATP? A Glycolysis proceeds when the intracellular concentration of ATP is low, which provides ATP to drive cellular reactions. B Glycolysis proceeds when the intracellular concentration of ATP is high and the cell stores ATP for future use. C Glycolysis is inhibited when the intracellular concentration of ATP is low because PFK requires ATP as a substrate for the reaction it catalyzes. D Glycolysis is inhibited when the intracellular concentration of ATP is high because ATP will compete with fructose 1,6-bisphosphate for binding to the active site on the enzyme.

A Glycolysis proceeds when the intracellular concentration of ATP is low, which provides ATP to drive cellular reactions.

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.

The active transport pump used to move sodium ions across the membranes of gill cells in a freshwater fish has each of the following characteristics EXCEPT: A It uses osmosis to carry sodium ions into the cells. B It requires energy. C It has a specific binding site for ATP. D It has a specific binding site for sodium ions. E It is a protein.

A It uses osmosis to carry sodium ions into the cells.

An experiment to measure the rate of respiration in crickets and mice at 10o C and 25o C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trials, and the following data were obtained. According to the data, the mice at 10o C demonstrated greater oxygen consumption per gram of tissue than did the mice at 25o C. This is most likely explained by which of the following statements? A The mice at 10o C had a higher rate of ATP production than the mice at 25o C. B The mice at 10o C had a lower metabolic rate than the mice at 25o C. C The mice at 25o C weighed less than the mice at 10o C. D The mice at 25o C were more active than the mice at 10o C.

A The mice at 10o C had a higher rate of ATP production than the mice at 25o C.

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.

When a substance moves across the plasma membrane along a concentration gradient at a rate faster than would be expected by simple diffusion alone but without the expenditure of metabolic energy, the process is best described as A facilitated diffusion B osmosis C active transport D pinocytosis E the work of an ion pump

A facilitated diffusion

The following questions refer to the following diagram. For each phrase or sentence, select the labeled part to which it is most closely related. Each option may be used once, more than once, or not at all for each group. Site of conversion of chemical energy of glucose to ATP

A mitochondria

Oxygen consumption can be used as a measure of metabolic rate because oxygen is A necessary for ATP synthesis by oxidative phosphorylation B necessary to replenish glycogen levels C necessary for fermentation to take place D required by all living organisms E required to break down the ethanol that is produced in muscles

A necessary for ATP synthesis by oxidative phosphorylation

Directions: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. (A) Glysolysis(B) Krebs cycle (citric acid cycle)(C) Calvin cycle (light-independent reactions of photosynthesis)(D) Light-dependent reactions of photosynthesis(E) Chemiosmosis Process in which CO2, is released as a by-product of oxidation-reduction reactions A A B B C C D D E E

B B

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

The following questions refer to the following diagram. For each phrase or sentence, select the labeled part to which it is most closely related. Each option may be used once, more than once, or not at all for each group. Site of glucose synthesis

B Chloroplasts

Q22 Respiration and Fermentation with 5 answer options 1.B 0/1 MC point 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

The illustration shows the active transport of hydrogen ions through a membrane protein. Which of the following best predicts the effect of not having ATP available to supply energy to this process? A H+H+ ions will stop moving through the protein. B H+H+ ions will move in the other direction through the protein. C H+H+ ions will continue to move through the protein in the original direction but at a slower rate. D H+H+ ions will begin to move through the phospholipid portion of the membrane in the original direction.

B H+H+ ions will move in the other direction through the protein.

The O2 released during photosynthesis comes from A CO2 B H2O C NADPH D RuBP (RuDP) E C6H12O6

B H2O

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?

Plant cell walls are composed of cellulose, while fungal cell walls are composed of chitin. A group of scientists hypothesize that this difference means the cell wall has largely different functions in plant cells and fungal cells. Alternatively, another group of scientists hypothesize that despite their biochemical differences, plant and fungal cell walls serve similar functions. Which of the following observations would best support the alternative hypothesis described above? A Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. B In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane. C Some plant cells have secondary cell walls that confer additional rigidity, while fungal cells do not. D Photosynthesis occurs in plant cells, but it does not occur in fungal cells.

B In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane.

Which of the following questions will best direct an investigation of the mechanism of ATP synthase? A What is the source of the inorganic phosphate that is used to generate ATP from ADP? B Is the phosphorylation of ADP by ATP synthase dependent on the formation of a proton gradient? C Can ATP synthase use the energy released by phosphorylation of ADP to pump protons against a concentration gradient? D Can oxidative phosphorylation be uncoupled from the electron transport chain?

B Is the phosphorylation of ADP by ATP synthase dependent on the formation of a proton gradient?

Which of the following statements best explains the processes of passive and active transport? A Passive transport is the net movement of substances down a concentration gradient that requires metabolic energy. Active transport is the movement of substances up a concentration gradient that does not require energy. B Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy. C Passive transport is the net movement of substances up a concentration gradient that requires metabolic energy. Active transport is the movement of substances down a concentration gradient that does not require metabolic energy. D Passive transport is the net movement of substances up a concentration gradient that does not require metabolic energy. Active transport is the movement of substances down a concentration gradient that requires energy.

B Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy.

Which of the following components of the cell membrane is responsible for active transport? A Phospholipid B Protein C Lipid D Phosphate E Cholesterol

B Protein

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

DNA and RNA are nucleic acids that can store biological information based on the sequence of their nucleotide monomers. Figure 1 shows a short segment of each of the two types of nucleic acids. Which of the following best describes a structural difference between DNA and RNA? Figure 1. Nucleic acid segments A DNADNA contains four types of nitrogenous bases, whereas RNARNA contains only two types of nitrogenous bases. B The backbone of DNADNA contains deoxyribose, whereas the backbone of RNARNA contains ribose. C A DNADNA molecule is composed of two parallel strands with the same 5′5′ to 3′3′ directionality, whereas an RNARNA molecule is composed of only one 5′5′ to 3′3′ strand. D Phosphate groups provide rigidity to DNADNA, but RNARNA is flexible and contains no phosphate groups.

B The backbone of DNADNA contains deoxyribose, whereas the backbone of RNARNA contains ribose.

Researchers compared similar proteins from related organisms in different habitats. They found that the proteins from organisms living in harsh environments had a greater number of cysteine amino acids than did proteins from organisms not living in harsh environments. The structure of cysteine is shown. Bonds can form between the sulfur atom of different cysteine amino acids (S-S bonds). Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins? A The change has no effect on the stability of the protein because only one type of amino acid is involved. B The change leads to increased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins. C The change leads to decreased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins. D The change leads to increased protein stability only when the added cysteine amino acids are next to other cysteine amino acids in the primary structure.

B The change leads to increased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins.

The model below shows the structure of a portion of a plasma membrane in an animal cell. Which statement best explains the orientation of the phospholipid molecules in this model? A The nonpolar portions of the phospholipid molecules are attracted to the internal and external environments. B The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments. C The embedded proteins attract the fatty acid tails of the phospholipids, so the tails point away from the internal and external aqueous environments. D The fatty acid tails of the phospholipid molecules are hydrophilic and are repelled by the internal and external aqueous environments.

B The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments.

Figure 1 represents a nucleic acid fragment that is made up of four nucleotides linked together in a chain. Figure 1. Nucleic acid fragment Which of the following characteristics of Figure 1 best shows that the fragment is RNA and not DNA? A The 5′5′ to 3′3′ orientation of the nucleotide chain B The identity of each nitrogenous base C The charges on the phosphate groups D The type of bond linking the nucleotides together

B The identity of each nitrogenous base

The figure above shows an organelle typically found in eukaryotic cells. Which of the following best describes the function of the double membrane system of this organelle? A The outer membrane allows the transport of all molecules into the intermembrane space, while the inner membrane serves as the regulatory boundary. B The inner membrane has specialized proteins that create a hydrogen ion concentration gradient between the intermembrane space and the matrix. C The outer membrane contains transport proteins that establish a sodium ion concentration gradient used for ATP production, while the inner membrane contains transport proteins that establish a hydrogen ion concentration gradient used for glucose production. D The toxins and wastes entering a cell cross the outer membrane and are detoxified by digestive enzymes stored within the intermembrane space.

B The inner membrane has specialized proteins that create a hydrogen ion concentration gradient between the intermembrane space and the matrix.

Which of the following best describes how amino acids affect the tertiary structure of a protein? A The number of amino acids determines the tertiary structure of the protein. B The interactions of the different RR-groups with other RR-groups and with their environment determine the tertiary structure of the protein. C The RR-group of the last amino acid that is added to a growing polypeptide chain determines the next amino acid that is added to the chain. D The sequence of the amino acids in the polypeptide chain determines the protein's primary structure but has no effect on its tertiary structure.

B The interactions of the different RR-groups with other RR-groups and with their environment determine the tertiary structure of the protein.

The figure shows a process by which a cell might absorb food from its surrounding environment and break it down for use as a source of energy and matter. The process involves lysosomes, which are membrane-bound organelles that contain hydrolytic enzymes. Activation of the hydrolytic enzymes requires an acidic pH, and lysosomes maintain an internal acidic pH by using ion pumps. Which of the following outcomes will most likely result from a loss of ion pump function in the cell's lysosomes? A The internal pHpH of the lysosomes will decrease, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food. B The internal pHpH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food. C The internal pHpH of the lysosomes will decrease, which will activate hydrolytic enzymes and enhance the intracellular digestion of food. D The internal pHpH of the lysosomes will increase, which will activate hydrolytic enzymes and enhance the intracellular digestion of food.

B The internal pHpH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food.

Water and ammonia interact to form hydrogen bonds, as represented in the figure. Which statement best helps explain the formation of the hydrogen bond represented in the figure? A The oxygen has a partial positive charge, and the nitrogen has a partial negative charge. B The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge. C The hydrogen attached to the oxygen has a partial negative charge, and the nitrogen also has a partial negative charge. D The nitrogen has a partial positive charge, and the hydrogen attached to the oxygen also has a partial positive charge.

B The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

Which of the following best describes the structures of carbohydrates? A They only occur as disaccharides. B They occur as monomers, chains of monomers, and branched structures. C They only occur as long and branched structures. D They occur as chains of monomers that hydrogen bond with complementary chains of monomers.

B They occur as monomers, chains of monomers, and branched structures.

Ultraviolet (UV) radiation can damage DNA by breaking weak bonds. Which of the following best explains how this occurs? A UVUV radiation disrupts the double helix structure by breaking the covalent bonds between the nitrogenous base pairs. B UVUV radiation disrupts the double helix structure by breaking the hydrogen bonds between the nitrogenous base pairs. C UVUV radiation is able to break DNADNA strands in two by breaking covalent bonds between the sugar-phosphate backbone molecules. D UVUV radiation is able to break DNADNA strands in two by breaking hydrogen bonds between the sugar-phosphate backbone molecules.

B UVUV radiation disrupts the double helix structure by breaking the hydrogen bonds between the nitrogenous base pairs.

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

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

Directions: Each group of questions below concerns an experimental or laboratory situation or data. In each case, first study the description of the situation or data. Then choose the one best answer to each question following it and fill in the corresponding circle on the answer sheet. Dialysis tubing is permeable to water molecules but not to sucrose. Four dialysis tubes are half filled with 5 percent, 10 percent, 20 percent, and 40 percent sucrose solutions, respectively, and two dialysis tubes are half filled with distilled water. The dialysis tubes are all sealed at both ends, and the initial masses are determined. Five dialysis tubes are placed into beakers containing distilled water, and the sixth dialysis tube, containing distilled water, is placed into a 40 percent sucrose solution. The masses of the dialysis tubes are recorded at 30-minute intervals for 90 minutes, as shown in the table below. To model a plant cell, a permeable, nonflexible case is placed around each piece of dialysis tubing. The greatest pressure potential will develop within dialysis tube number A 2 B 3 C 4 D 5 E 6

C 4

Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells? A An increase in blood pH due to the accumulation of lactic acid B No ATP production due to the absence of substrate-level phosphorylation C A buildup of lactic acid in the muscle tissue due to fermentation D A decrease in the oxidation of fatty acids due to a shortage of ATP

C A buildup of lactic acid in the muscle tissue due to fermentation

Figure 1. Formation of a peptide bond Which of the following best describes the formation of the bond shown in Figure 1 ? A An ionic bond is formed between a carbon atom of one amino acid and the nitrogen atom of the other amino acid. B An ionic bond is formed when the negative charge of an OHOH group is balanced by the positive charge of a hydrogen ion. C A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2OH2O . D A covalent bond is formed that replaces the hydrogen bond between the OHOH group and the HH atom.

C A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2OH2O .

Figure 1 shows a model of how a channel protein influences the movement of a particle across a cell's plasma membrane. Figure 1. A section of a cell's plasma membrane, showing a channel protein and a concentration gradient across the membrane An investigator wants to understand whether a newly found membrane protein is involved in membrane transport of a certain particle. Which investigation will help determine whether the new membrane protein is a channel protein involved in membrane transport? A Add small nonpolar molecules to the extracellular space and measure the direction of particle movement of the molecules. B Measure the rate of extracellular fluid movement into the intracellular space. C Add more of the proteins to the plasma membrane and measure the rate of the particle movement. D Remove ATPATP from the intracellular space and measure the rate of the particle movement into the intracellular space.

C Add more of the proteins to the plasma membrane and measure the rate of the particle movement.

Directions: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. (A) Glysolysis(B) Krebs cycle (citric acid cycle)(C) Calvin cycle (light-independent reactions of photosynthesis)(D) Light-dependent reactions of photosynthesis(E) Chemiosmosis Process in which carbon from CO2 is incorporated into organic molecules A A B B C C D D E E

C C

The following questions refer to the following diagram. For each phrase or sentence, select the labeled part to which it is most closely related. Each option may be used once, more than once, or not at all for each group. Site of modification and packaging of proteins and lipids prior to export from the cell

C Golgi body

Figure 1. An amino acid 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 (NH2NH2) group B Carboxyl (COOHCOOH) group C Methyl (CH3CH3) group D Hydrogen (HH) atom

C Methyl (CH3CH3) group

The molecular structures of linoleic acid and palmitic acid, two naturally occurring substances, are shown in the figure. Based on the molecular structures shown in the figure, which molecule is likely to be solid at room temperature? A Linoleic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together. B Linoleic acid, because the presence of carbon-carbon double bonds prevents the molecules from packing closely together. C Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together. D Palmitic acid, because the presence of carbon-carbon double bonds prevents the molecules from packing closely together.

C Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together.

Researchers have proposed a model of the process by which a newly synthesized protein is transported to the plasma membrane and secreted into the extracellular space. The model is represented in Figure 1. Figure 1. A model of the intracellular transport of a newly synthesized secreted protein Based on the model, the newly synthesized protein is transported directly from the endoplasmic reticulum to which of the following? A The nucleus B The plasma membrane C The Golgi complex D The extracellular space

C The Golgi complex

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.

Researchers claimed that a particular organelle originated from a free-living prokaryotic cell that was engulfed by a larger cell, as shown in Figure 1. Figure 1. A model showing a cell engulfing a smaller cell Which of the following provides evidence to best support the researchers' claim? A The organelle has a phospholipid membrane. B The organelle has protein in the membrane. C The organelle has a double membrane. D The organelle has an internal aqueous environment that is similar to the cytosol of the larger cell.

C The organelle has a double membrane.

Aquaporins are channel proteins that facilitate the transport of water across the cell membrane. One group of researchers hypothesizes that without functional aquaporins, no water will be able to enter the cell. A different group proposes an alternative hypothesis, stating that even with nonfunctional aquaporins, a small amount of water will still cross the cell membrane. An experiment is set up in which plant cells with mutated (nonfunctional) aquaporins and plant cells with normally functioning aquaporins are both placed in distilled water. Which of the following data would support the alternative hypothesis? A Cells with functional aquaporins exhibit low turgor pressure and are hypertonic. B Cells with functional aquaporins exhibit high turgor pressure and are hypotonic. C Cells with mutated aquaporins exhibit an absence of turgor pressure and are completely plasmolyzed. D Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.

D Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.

Directions: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. (A) Glysolysis(B) Krebs cycle (citric acid cycle)(C) Calvin cycle (light-independent reactions of photosynthesis)(D) Light-dependent reactions of photosynthesis(E) Chemiosmosis Process in which O2 is released as a by-product of oxidation-reduction reactions A A B B C C D D E E

D D

Figure 1 is a diagram of water molecules at the air-water interface at the surface of a pond. Figure 1. Alignment of water molecules at air-water interface Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface? A Covalent bonds between water molecules and the air above provide cohesion, which causes tiny bubbles to form under the feet of the insect. B Ionic bonds between molecules at the surface of the water provide an electric charge, which attracts the feet of the insect, keeping it on the surface. C Polar covalent bonds between molecules at the surface of the water provide adhesion, which supports the weight of the insect. D Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

D Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

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.

Polypeptides are continuously being formed and degraded. One of these processes is shown. Figure 1. Polypeptide reaction Which statement is the most accurate description of the reaction shown in Figure 1? A It represents monomers linked by dehydration synthesis. B It represents a polypeptide chain that folds to form the tertiary structure. C It represents a polypeptide chain that is denatured into the primary structure. D It represents a polypeptide chain that is broken down through a hydrolysis reaction.

D It represents a polypeptide chain that is broken down through a hydrolysis reaction.

The CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain. Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein? A It will have no observable effect on the structure of the CFTRCFTR protein. B It will affect the primary structure of the CFTRCFTR protein, but the other levels of protein structure will not be affected. C It will affect the secondary and tertiary structures of the CFTRCFTR protein, but the primary structure will not be affected. D It will affect the primary, secondary, and tertiary structures of the CFTRCFTR protein.

D It will affect the primary, secondary, and tertiary structures of the CFTRCFTR protein.

Which of the following conclusions is most clearly supported by the representations of nucleic acid #1 and nucleic acid #2 ? A Nucleic acid #1#1 contains only purines, whereas nucleic acid #2#2 contains only pyrimidines. B Nucleic acid #1#1 contains the sugar ribose, whereas nucleic acid #2#2 contains the sugar deoxyribose. C Nucleic acid #1#1 contains positively charged phosphate groups, whereas nucleic acid #2#2 does not. D Nucleic acid #1#1 contains adenine-thymine base pairs, whereas nucleic acid #2#2 does not.

D Nucleic acid #1#1 contains adenine-thymine base pairs, whereas nucleic acid #2#2 does not.

What most likely causes the trends in oxygen concentration shown in the graph above? A The water becomes colder at night and thus holds more oxygen. B Respiration in most organisms increases at night. C More organisms are respiring at night than during the day. D Photosynthesis produces more oxygen than is consumed by respiration during the day.

D Photosynthesis produces more oxygen than is consumed by respiration during the day.

A spherical bacterial cell has a radius of 3μm. The human egg cell has a radius of 100μm. Which statement correctly indicates the cell that is able to more efficiently exchange materials with the external environment and provides a correct explanation? A The egg cell, because it has the smallest surface-to-volume ratio. B The egg cell, because it has the largest surface-to-volume ratio. C The bacterial cell, because it has the smallest surface-to-volume ratio. D The bacterial cell, because it has the largest surface-to-volume ratio.

D The bacterial cell, because it has the largest surface-to-volume ratio.

Figure 1 represents a common process that occurs in organisms. Figure 1. Structural formula for a common biological reaction Which of the following is an accurate description of the process shown in Figure 1 ? A The linking of amino acids with an ionic bond as an initial step in the protein synthesis process B The formation of a more complex carbohydrate with the covalent bonding of two simple sugars C The hydrolysis of amino acids with the breaking of covalent bonds with the release of water D The formation of a covalent peptide bond in a dehydration synthesis reaction

D The formation of a covalent peptide bond in a dehydration synthesis reaction

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.

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 inthe mitochondrial matrix D electrons flowing along the electron transportchain E substrate-level phosphorylation

D electrons flowing along the electron transportchain

Directions: Each group of questions below concerns an experimental or laboratory situation or data. In each case, first study the description of the situation or data. Then choose the one best answer to each question following it and fill in the corresponding circle on the answer sheet. Dialysis tubing is permeable to water molecules but not to sucrose. Four dialysis tubes are half filled with 5 percent, 10 percent, 20 percent, and 40 percent sucrose solutions, respectively, and two dialysis tubes are half filled with distilled water. The dialysis tubes are all sealed at both ends, and the initial masses are determined. Five dialysis tubes are placed into beakers containing distilled water, and the sixth dialysis tube, containing distilled water, is placed into a 40 percent sucrose solution. The masses of the dialysis tubes are recorded at 30-minute intervals for 90 minutes, as shown in the table below. The contents of which dialysis tube are initially isotonic to the distilled water in the beaker? A 1 B 2 C 3 D 4 E 5

E 5

Directions: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. (A) Glysolysis(B) Krebs cycle (citric acid cycle)(C) Calvin cycle (light-independent reactions of photosynthesis)(D) Light-dependent reactions of photosynthesis(E) Chemiosmosis Process found in both photosynthesis and cellular respiration A A B B C C D D E E

E E

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.

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

Directions: Each group of questions below concerns an experimental or laboratory situation or data. In each case, first study the description of the situation or data. Then choose the one best answer to each question following it and fill in the corresponding circle on the answer sheet. Dialysis tubing is permeable to water molecules but not to sucrose. Four dialysis tubes are half filled with 5 percent, 10 percent, 20 percent, and 40 percent sucrose solutions, respectively, and two dialysis tubes are half filled with distilled water. The dialysis tubes are all sealed at both ends, and the initial masses are determined. Five dialysis tubes are placed into beakers containing distilled water, and the sixth dialysis tube, containing distilled water, is placed into a 40 percent sucrose solution. The masses of the dialysis tubes are recorded at 30-minute intervals for 90 minutes, as shown in the table below. A net movement of water into the beaker occurs in which of the following dialysis tubes? A 2 B 3 C 4 D 5 E 6

E6