Bartleby Sitemap - Textbook Solutions
All Textbook Solutions for Biology: The Dynamic Science (MindTap Course List)
1SBWhat do living organisms do with the energy they collect from the external environment?What is a life cycle?What is the difference between artificial selection and natural selection?How do random changes in the structure of DNA affect the characteristics of organisms?3SBWhat is a major difference between prokaryotic and eukaryotic organisms?2SB3SBIn your own words, explain the most important requirement of a scientific hypothesis.What information did the copper lizard models provide in the study of temperature regulation described earlier?3SBWhat is the lowest level of biological organization that biologists consider to be alive? a. a protein b. DNA c. a cell d. a multicellular organism e. a population of organismsWhich category falls immediately below class in the systematic hierarchy? a. species b. order c. family d. genus e. phylumHouseflies develop through a series of programmed stages from egg, to larva, to pupa, to flying adult. This series of stages is called: a. artificial selection. b. respiration. c. homeostasis. d. a life cycle. e. metabolism.Which structure allows living organisms to detect changes in the environment? a. a protein b. a receptor c. a gene d. RNA e. a nucleus5TYK6TYKWhich of the following represents the application of the scientific method? a. comparing one experimental subject to one control subject b. believing an explanation that is too complex to be tested c. using controlled experiments to test falsifiable hypotheses d. developing one testable hypothesis to explain a natural phenomenon e. observing a once-in-a-lifetime event under natural conditionsWhich of the following is not a component of Darwins theory as he understood it? a. Some individuals in a population survive longer than others. b. Some individuals in a population reproduce more thanothers. c. Heritable variations allow some individuals to compete moresuccessfully for resources. d. Mutations in genes produce new variations in a population. e. Some new variations are passed to the next generation.Which of the following questions best exemplifies basic research? a. How did life begin? b. How does alcohol intake affect aging? c. How fast does H1N1 flu spread among humans? d. How can we reduce hereditary problems in purebred dogs? e. How does the consumption of soft drinks promote obesity?When researchers say that a scientific hypothesis must be falsifiable, they mean that: a. the hypothesis must be proved correct before it is accepted astruth. b. the hypothesis has already withstood many experimentaltests. c. they have an idea about what will happen to one variable ifanother variable changes. d. appropriate data can prove without question that thehypothesis is correct. e. if the hypothesis is wrong, scientists must be able todemonstrate that it is wrong.11TYKWhat role did the copper lizard models play in the field study of temperature regulation? a. They attracted live lizards to the study site. b. They measured the temperatures of live lizards. c. They established null hypotheses about basking behavior and temperatures. d. They scared predators away from the study site. e. They allowed researchers to practice taking lizardtemperatures.13TYK14TYKApply Evolutionary Thinking When a biologist first tested a new pesticide on a population of insects, she found that only 1% of the insects survived their exposure to the poison. She allowed the survivors to reproduce and discovered that 10% of the offspring survived exposure to the same concentration of pesticide. One generation later, 50% of the insects survived this experimental treatment. What is a likely explanation for the increasing survival rate of these insects over time?1ITDDistinguish between an element and an atom, and between a molecule and a compound.1SB2SB3SB1SB2SB3SB4SB1SB2SB1SBWhy are buffers important for living organisms?Which of the following statements about the mass number of an atom is incorrect? a. It has a unit defined as a dalton. b. On Earth, it equals the atomic weight. c. Unlike the atomic weight of an atom, it does not change when gravitational forces change. d. It equals the number of electrons in an atom. e. It is the sum of the protons and neutrons in the atomic nucleus.Oxygen (O) is a(n) _______; the oxygen we breathe (O2) is a(n) _______; and the carbon dioxide we exhale is a(n) _______. a. compound; molecule; element b. atom; compound; element c. element; atom; molecule d. atom; element; molecule e. element; molecule; compoundThe chemical activity of an atom: a. depends on the electrons in the outermost energy level. b. is increased when the outermost energy level is filled withelectrons. c. depends on its 1s but not its 2s or 2p orbitals. d. is increased when valence electrons completely fill the outerorbitals. e. of oxygen prevents it from sharing its electrons with otheratoms.When electrons are shared equally between atoms, they form: a. a polar covalent bond. b. a nonpolar covalent bond. c. an ionic bond. d. a hydrogen bond. e. a van der Waals force.Which of the following is not a property of water? a. It has a low boiling point compared with other molecules. b. It has a high heat of vaporization. c. Its molecules resist separation, a property called cohesion. d. It has the property of adhesion, the ability to stick to chargedand polar groups in molecules. e. It can form hydrogen bonds to molecules below but not aboveits surface.The water lattice: a. is formed from hydrophobic bonds. b. causes ice to be denser than water. c. causes water to have a relatively low specific heat. d. excludes nonpolar substances. e. is held together by hydrogen bonds that are permanent; that is, they never break and reform.A hydrogen bond is: a. a strong attraction between hydrogen and another atom. b. a bond between a hydrogen atom already covalently bound to one atom and made partially negative by unequal electron sharing with another atom. c. a bond between a hydrogen atom already covalently bound to one atom and made partially positive by unequal electron sharing with another atom. d. weaker than van der Waals forces. e. exemplified by the two hydrogens covalently bound to oxygen in the water molecule.Apply Evolutionary Thinking What properties of water made the evolution of life possible?If pond water has a pH of 5, the hydroxide concentration would be: a. 10-5M. b. 10-10M. c. 105M. d. 109M. e. 10-9M.10TYK11TYK12TYKDiscuss Concepts You place a metal pan full of water on the stove and turn on the heat. After a few minutes, the handle is too hot to touch but the water is only warm. How do you explain this observation?14TYK15TYKThe pH of human stomach acid ranges from 1.0 to 3.0, whereas a healthy esophagus has a pH of approximately 7.0. In gastroesophageal reflux disease (GERD), often called acid reflux, stomach acid flows backward from the stomach into the esophagus. Repeated episodes in which esophageal pH goes below 4.0, considered clinical acid reflux, can result in bleeding ulcers and damage to the esophageal lining. The data in the Figure, from a patient with GERD, show esophageal pH during a sleeping reflux event. How many minutes does it take to go from the peak of the reflux event (when pH is most acidic) to when the reflux event is over? Source: Based on T. Demeester et al. 1976. Patterns of gastroesophageal reflux in health and disease. Annals of Surgery 184:459469.2ITD3ITDWhat is the difference between hydrocarbons and other organic molecules?What is the maximum number of bonds that a carbon atom can form?Do carboxyl groups, amino groups, and phosphate groups act as acids or bases?What is the difference between a dehydration synthesis reaction (condensation reaction) and hydrolysis?What is the difference between a monosaccharide, a disaccharide, and a polysaccharide? Give examples of each.What are the three most common lipids in living organisms? How do their structures differ?1SBWhat is a peptide bond, and what type of reaction forms it?3SBWhat is the monomer of a nucleic acid macromolecule?What are the chemical differences between DNA and RNA?Which functional group has a double bond and forms organic acids? a. carboxyl b. amino c. hydroxyl d. carbonyl e. sulfhydrylWhich of the following characteristics is not common to carbohydrates, lipids, and proteins? a. They are composed of a carbon backbone with functionalgroups attached. b. Monomers of these molecules undergo dehydration synthesisto form polymers. c. Their polymers are broken apart by hydrolysis. d. The backbones of the polymers are primarily polar molecules. e. The molecules are held together by covalent bonding.Cellulose is to carbohydrate as: a. amino acid is to protein. b. lipid is to fat. c. collagen is to protein. d. nucleic acid is to DNA. e. nucleic acid is to RNA.Maltose, sucrose, and lactose differ from one another: a. because not all contain glucose. b. because not all of them exist in ring form. c. in the number of carbons in the sugar. d. in the number of hexose monomers involved. e. by the linkage of the monomers.Lipids that are liquid at room temperature: a. are fats. b. contain more hydrogen atoms than lipids that are solids at room temperature. c. if polyunsaturated, contain several double bonds in their fatty acid chains. d. lack glycerol. e. are not stored in cells as triglycerides.Which of the following statements about steroids is false? a. They are classified as lipids because, like lipids, they arenonpolar. b. They can act as regulatory molecules in animals. c. They are composed of four carbon rings. d. They are highly soluble in water. e. Their most abundant form is as sterols.The term secondary structure refers to a proteins: a. sequence of amino acids. b. structure that results from local interactions betweendifferent amino acids in the chain. c. interactions with a second protein chain. d. interaction with a chaperonin. e. interactions with carbohydrates.The first and major effect in denaturation of proteins is that: a. peptide bonds break. b. helices unwind. c. sheet structures unfold. d. tertiary structure is changed. e. quaternary structures disassemble.In living systems: a. proteins rarely combine with other macromolecules. b. enzymes are always proteins. c. proteins are composed of 24 amino acids. d. chaperonins inhibit protein movement. e. a protein domain refers to the place in the cell where proteins are synthesized and function.RNA differs from DNA because: a. RNA may contain the pyrimidine uracil, and DNA does not. b. RNA is always single-stranded when functioning, and DNA isalways double-stranded. c. the pentose sugar in RNA has one less O atom than thepentose sugar in DNA. d. RNA is more stable and is broken down by enzymes lesseasily than DNA. e. RNA is a much larger molecule than DNA.Discuss Concepts Identify the following structures as a carbohydrate, fatty acid, amino acid, or polypeptide: a. (The R indicates an organic group.) b. C6H12O6 c. (glycine)20 d. CH3(CH2)16COOHDiscuss Concepts Lipoproteins are relatively large, spherical clumps of protein and lipid molecules that circulate in the blood of mammals. They are like suitcases that move cholesterol, fatty acid remnants, triglycerides, and phospholipids from one place to another in the body. Given what you know about the insolubility of lipids in water, which of the three kinds of lipids would you predict to be on the outside of a lipoprotein clump, bathed in the fluid portion of blood?13TYK14TYK15TYK1ITD2ITD3ITD1SBWhere in a prokaryotic cell is DNA found? How is that DNA organized?Where in a eukaryotic cell is DNA found? How is that DNA organized?2SBExplain the structure and function of the endomembrane system.4SBWhat is the structure and function of the cytoskeleton?1SB2SBWhat are the structures and function of anchoring junctions, tight junctions, and gap junctions?2SBA prokaryote converts food energy into the chemical energy of ATP on/in its: chromosome. flagella. ribosomes. cell wall. plasma membrane.Eukaryotic and prokaryotic ribosomes are similar in that: a. both contain a small subunit, but only eukaryotes contain a large subunit. b. both contain the same number of proteins. c. both use mRNA to assemble amino acids into proteins. d. both contain the same number of types of rRNA. e. both produce proteins that can pass through pores into the nucleus.Which of the following structures does not require an immediate source of energy to function? a. central vacuoles b. cilia c. microtubules d. microfilaments e. microbodiesWhich of the following structures is not used in eukaryotic protein manufacture and sectretion? a. ribosome b. lysosome c. rough ER d. secretory vesicle e. Golgi complexWhich of the following are glycoproteins whose function is affected by the common cold birus? a. plasmodesmata b. desmosomes c. cell adhesion molecules d. flagella e. cilia6TYKWhich of the following statements about proteins is correct? a. Proteins are transported to the rough ER for use within the cell. b. Lipids and carbohydrates are added to proteins by the Golgi complex. c. Proteins are transported directly into the cytosol for secretion from the cell. d. Proteins that are to be stored by the cell are moved to the rough ER. e. Proteins are synthesized in vesicles.Which of the following is not a component of the cytoskeleton? a. microtubules b. actins c. microfilaments d. cilia e. cytokeratinsDiscuss Concepts Explain why aliens invading Earth are not likely to be giant cells the size of humans.You are examining a cell from a crime scene using an electron microscope. It contains ribosomes, DNA, a plasma membrane, a cell wall, and mitochondria. What type of cell is it? a. lung cell b. plant cell c. prokaryotic cell d. cell from the surface of a human fingernail e. sperm cell11TYK12TYK13TYK14TYK15TYK16TYK17. The unicellular alga Chlamydomonas reinhardtii has two flagella assembled from tubulin proteins. If a researcher changes the pH from approximately neutral (their normal growing condition) to pH 4.5, Chlamydomonas cells spontaneously lose their flagella. After the cells are returned to neutral pH, they regrow the flagella—a process called reflagellation. Assuming that you have deflagellated Chlamydomonas cells, devise experiments to answer the following questions:
1. Do new tubulin proteins need to be made for reflagellation to occur, or is there a reservoir of proteins in the cell?
2. Is the production of new mRNA for the tubulin proteins necessary for reflagellation?
3. What is the optimal pH for reflagellation?
1ITDDescribe the fluid mosaic model for membrane structure.Give two examples each of integral proteins and peripheral proteins.What is the difference between passive and active transport?2SB1SB2SB1SB2SB1SB2SBIn the fluid mosaic model: plasma membrane proteins orient their hydrophilic sides toward the internal bilayer. phospholipids often flip-flop between the inner and outer layers. the mosaic refers to proteins attached to the underlying cytoskeleton. the fluid refers to the phospholipid bilayer. the mosaic refers to the symmetry of the internal membrane proteins and sterols.Which of the following statements is false? Proteins in the plasma membrane can: a. transport ions. b. transport chloride ions when there are two mutant copies of the cystic fibrosis transmembrane conductance regulator gene. c. recognize self versus foreign molecules. d. allow adhesion between the same tissue cells or cells of different tissues. e. combine with lipids or sugars to form complex macromolecules.The freeze-fracture technique demonstrated: a. that the plasma membrane is a bilayer with individual proteins suspended in it. b. that the plasma membrane is fluid. c. that the arrangement of membrane lipids and proteins is symmetric. d. that proteins are bound to the cytoplasmic side but not embedded in the lipid bilayer. e. the direction of movement of solutes through the membrane.A characteristic of carrier molecules in a primary active transport pump is that: a. they cannot transport a substance and also hydrolyze ATP. b. they retain their same shape as they perform different roles. c. their primary role is to move negatively charged ions across membrances. d. they move Na+ into a neural cell and K+ out of the same cell. e. they act to establish an electrochemical gradient.A driving ion moving through a membrane channel in one direction gives energy to actively transport another molecule in the opposite direction. What is this process called? a. facilitated diffusion b. antiport transport c. symport transport d. primary active transport pump e. contransportPhagocytosis illustrates which phenomenon? a. receptor-mediated endocytosis b. bulk endocytosis c. exocytosis d. pinocytosis e. cotransportPlace in order the following events of receptor-mediated endocytosis. (1) Clathrin coat disappers. (2) Receptors collect in a coated pit covered with clathrin on the cytoplasmic side. (3) Receptors recognize and bind specific molecules. (4) Endocytic vesicle may fuse with lysosome whereas receptors are recycled to the cell surface. (5) Pits deepen and pinch free of plasma membrane to form endocytic vesicles. a. 4, 1, 2, 5, 3 b. 2, 1, 3, 5, 4 c. 3, 2, 5, 1, 4 d. 4, 1, 5, 2, 3 e. 3, 1, 2, 4, 58TYKWhich of the following statements is true for the figure in question 8? a. The net movement of solutes is into the cell. b. There is no concentration gradient. c. There is a potential for plasmolysis. d. The solvent will move against its concentration gradient. e. If this were a plant cell, turgor pressure would be maintained.Using the principle of diffusion, a dialysis machine removes waste solutes from a patients blood. Imagine blood runs through a cylinder wherein diffusion can occur across an artificial selectively permeable membrane to a saline solution on the other side. Which of the following statements is correct? a. Solutes move from lower to higher concentraction. b. The concentration gradient is lower in the patients blood than in the saline solution wash. c. The solutes are transported through a symport in the blood cell membrane. d. The saline solution has a lower concentration gradient of solute than the blood. e. The waste solutes are actively transported from the blood.Discuss Concepts The bacterium Vibrio cholera causes cholera, a disease characterized by severe diarrhea that may cause infected people to lose up to 20 L of fluid in a day. The bacterium enters the body when someone drinks contaminated water. It adheres to the intestinal lining, where it causes cells of the lining to release sodium and chloride ions. Explain how this release is related to the massive fluid loss.12TYK13TYK14TYK15TYKSome cancer cells are insensitive to typical chemotherapy. Research into the mechanisms underlying this insensitivity uncovered an ability by these cells to pump the treatment drug out of the cell against its concentration gradient. Additional drugs have been developed that inhibit the pump, thus trapping the chemotherapeutic agent inside to promote cancer cell destruction. The Figure shows what happens when two types of cells are treated with a 3H-labeled anti-cancer drug, paclitaxel. Which set of cells (A or B) would be described as resistant to the cancer treatment? Explain your answer. What type of transport are the resistant cells using?Some cancer cells are insensitive to typical chemotherapy. Research into the mechanisms underlying this insensitivity uncovered an ability by these cells to pump the treatment drug out of the cell against its concentration gradient. Additional drugs have been developed that inhibit the pump, thus trapping the chemotherapeutic agent inside to promote cancer cell destruction. The Figure shows what happens when two types of cells are treated with a 3H-labeled anti-cancer drug, paclitaxel. Two additional drugs, imatinib and nilotinib, are evaluated for their ability to overcome the cancer cells ability to pump out the chemotherapeutic agent. An asterisk (*) indicates a statistically significant difference from the cells receiving paclitaxel alone. Do the additional drugs seem to the effective in over-coming the pump? Which set of graphs (A or B) best supports your answer? Explain your answer.1SBIn thermodynamics, what is meant by an isolated system, a closed system, and an open system?1SB2SBDistinguish between exergonic and endergonic reactions, and between catabolic and anabolic reactions. How are the two categories of reactions related?1SBHow are coupled reactions important to cell function? How is ATP involved in coupled reactions?How do enzymes increase the rates of the reaction they catalyze?Can enzymes alter the G of a reaction?1SBWhat is the difference between competitive and noncompetitive inhibition?3SB1SBThe capacity to do work best defines: a metabolic pathway. entropy. kinetic or potential energy. a chemical equilibrium. thermodynamics.The assembly of proteins from amino acids is best described as: a. a conversion of kinetic energy to potential energy reaction. b. an entropy reaction. c. a catabolic reaction. d. an anabolic reaction. e. an energy-free reaction.When two glucose molecules react to form maltose: a. the reaction represents a negative G. b. free energy had to be available to allow the reaction to proceed. c. the reaction is exothermic. d. it supports the second law of thermodynamics, which states there is tendency of the universe toward disorder. e. the resulting product has less potential energy than the reactants.When glucose reacts with ATP to form glucose-6-phosphate: a. the synthesis of glucose-6-phosphate is exergonic. b. ADP is at a higher energy level than ATP. c. glucose-6-phosphate is at a higher energy level than glucose. d. because ATP donates a phosphate to glucose, this is not a coupled reaction. e. the reaction is spontaneous.In the following graph: A represents the product. B represents the energy of activation when enzymes are present. C is the free energy difference between A and D. C is the energy of activation without enzymes. E is the difference in free energy between the reactant and the products.Which of the following methods is not used by enzymes to increase the rate of reactions? a. covalent bonding with the substrate at their active site b. bringing reacting molecules into close prosimity c. orienting reactants into positions to favor transition states d. changing charges on reactants to hasten their reactivity e. increasing fit of enzyme and substrate that reduces the energy of activationIn an enzymatic reaction: a. the enzyme leaves the reaction chemically unchanged. b. if the enzyme molecules approach maximal rate, and the substrate is continually increased, the rate of the reaction does not reach saturation. c. in the stomach, enzymes would have an optimal activity at a neutral pH. d. increasing temperature above the optimal value slows the reaction rate. e. the least important level of organization for an enzyme is its tertiary structure.Which of the following statements about the allosteric site is true? a. The allosteric site is a second active site on a substrate in a metabolic pathway. b. The allosteric site on an enzyme can allow the product of a metabolic pathway to inhibit that enzyme and stop the pathway. c. When the allosteric site of an enzyme is occupied, the reaction is irreversible and the enzyme cannot react again. d. An allosteric activator prevents binding at the active site. e. An enzyme that possesses allosteric sites does not possess an active site.Which of the following statements about inhibition is true? a. Allosteric inhibitors and allosteric activators are competitive for a given enzyme. b. If an inhibitor binds the active site, it is considered noncompetitive. c. If an inhibitor binds to a site other than the active site, this competitive inhibition. d. A noncompetitive inhibitor is believed to change the shape of the enzyme, making its active site inoperable. e. Competitive inhibition is usually not reversible.Which of the following statements is incorrect? a. Ribozymes can link amino acids to form protein. b. Ribozymes can act as enzymes. c. Ribozymes can act as informational molecules. d. Ribozymes are suggested as the first molecules of life. e. Ribozymes are proteins.11TYKDiscuss Concepts Trace the flow of energy through your body. What products increase the entropy of you and your surroundings?13TYK14TYK15TYK16TYK17TYK1ITD2ITD3ITD1SBDistinguish between cellular respiration and oxidative phosphorylation.1SBWhat is the redox reaction in glycolysis?How is ATP synthesized in glycolysis?Summarize the fate of pyruvate molecules produced by glycolysis.What distinguishes the four complexes of the mitochondrial electron transfer system?2SB1SB2SB1SBWhat are the types of molecules that are the immediate products of biosynthetic pathways that start from glycolysis and the citric acid cycle?3SBWhat is the final acceptor for electrons in cellular respiration? a. oxygen b. ATP c. carbon dioxide d. hydrogen e. water2TYK3TYK4TYK5TYK6TYK7TYK8TYKWhich of the following statements is false? Imagine that you ingested three chocolate bars just before sitting down to study this chapter. Most likely: a. your brain cells are using ATP. b. there is no deficit of the initial substrate to begin glycolysis. c. the respiratory processes in your brain cells are moving atomsfrom glycolysis through the citric acid cycle to the electrontransfer system. d. after a couple of hours, you change position and stretch torest certain muscle cells, which removes lactate from thesemuscles. e. after 2 hours, your brain cells are oxygen-deficient.In the 1950s, a diet pill that had the effect of poisoning ATP synthase was tried. The person taking it could not use glucose and lost weightand ultimately his or her life. Today, we know that the immediate effect of poisoning ATP synthase is: a. ATP would not be made in the electron transfer system. b. H+ movement across the inner mitochondrial membranewould increase. c. more than 32 ATP could be produced from a molecule ofglucose. d. ADP would be united with phosphate more readily in themitochondria. e. ATP would react with oxygen.Discuss Concepts Why do you think nucleic acids are not oxidized extensively as a cellular energy source?A hospital patient was regularly found to be intoxicated. He denied that he was drinking alcoholic bevarages. The doctors and nurses made a special point to eliminate the possibility that the patient or his friends were smuggling alcohol into his room, but he was still regularly intoxicated. Then, one of the doctors had an idea that turned out to be correct and cured the patient of his intoxication. The idea involved the patients digestive system and one of the oxidative reactions covered in this chapter. What was the doctors idea? 13. There are several ways to measure cellular respiration experimentally. For example, CO2 and O2 gas sensors measure changes over time in the concentration of carbon dioxide or oxygen, respectively. Design two experiments to test the effects of changing two different variables or conditions (one per experiment) on the respiration of research organism of your choice.
Apply Evolutionary Thinking Which of the two phosphorylation mechanisms, oxidative phosphorylation or substrate-level phosphorylation, is likely to have appeared first in evolution? Why?1ITD2ITDAs CO2 concentrations increase in the atmosphere, biologists continue to explore the role of respiration from plants as a small but potentially important contribution beyond fossil fuel combustion. The data in the Table were collected from the leaf of a sagebrush plant from a semiarid ecosystem in Wyoming, enclosed in a chamber that measures the rate of CO2 exchange. The respiration rate is the amount of CO2 in micromoles lost by the leaf per square meter per second, which results in the negative numbers. The temperature values are from the leaves as they are heated or cooled during the measurements. Observation Temperature (C) Respiration Rate (mol/m2/s) 1 25 -2.0 2 30 -2.7 3 35 -4.1 4 40 -5.8 5 20 -1.3 6 15 -1.0 7 10 -0.7 Cengage Learning 2017 What describes the relationship between temperature and respiration, a line or a curve? Does the Q10 that you calculated in 2 suggest a line or a curve? Source: Data based on unpublished research by Brent Ewers, University of Wyoming.4ITDWhat are the two stages of photosynthesis?In which organelle does photosynthesis take place in plants? Where in that organelle are the two stages of photosynthesis carried out?What is the difference in function between the chlorophyll a molecules in the antenna complexes and the chlorophyll a molecules in the reaction centers of the photosystems?2SBWhat is the difference between the linear electron flow pathway and the cyclic electron flow pathway?What is the reaction that rubisco catalyzes? Why is rubisco the key enzyme for producing the worlds food, and how is it the key regulatory site of the Calvin cycle?How many molecules of carbon dioxide must enter the Calvin cycle for a plant to produce a sugar containing 12 carbon atoms? How many ATP and NADPH molecules would be required to make that molecule?1SB2SBHow are carbon fixation and the Calvin cycle different in C4 plants and CAM plants?How are the reactants and products of photosynthesis and cellular respiration related?An organism exists for long periods by using only CO2 and H2O. herbivore. carnivore. decomposer. autotroph. heterotroph.2TYKWhich of the following is a correct step in the light-dependent reactions of the Z system? a. Light is absorbed at P700, and electrons flow through a pathway to NADP+, the final acceptor of the linear pathway. b. Electrons flow from photosystem II to water. c. NADP+ is oxidized to NADPH as it accepts electrons. d. Water is degraded to activate P680. e. Electrons pass through a thylakoid membrane to create energy to pump H+ through the cytochrome complex.4TYK5TYKWhich of the following statements about the C4 cycle is incorrect? a. CO2 initially combines with PEP. b. PEP carboxylase catalyzes a reaction to produce oxaloacetate. c. Oxaloacetate transfers electrons from NADPH and is reduced to malate. d. Less ATP is used to run the C4 cycle than the C3 cycle. e. The cycle runs when O2 concentration is high.7TYKThe oxygen released by photosynthesis comes from: a. CO2. b. H2O. c. light. d. NADPH. e. electrons.You bite into a spinach leaf. Which one of the following is true? a. You are getting 50% of the protein in the leaf in the form ofribulose 1,5-bisphosphate carboxylase. b. The major pigment you are ingesting is a carotenoid. c. The water in the leaf is a product of the light-independentreactions. d. Any energy from the leaf you can use directly is in the form ofATP. e. The spinach most likely was grown in an area with a low CO2 concentration.Animal metabolism and plant metabolism are related in that: a. plants carry out photosynthesis and animals carry outrespiration. b. G3P is found in the metabolic pathways of both animals andplants. c. G3P is used by catabolic pathways when it is generated byphotosynthesis, and it is a product of an anabolic pathway incellular respiration. d. light drives electron excitation. e. the reactants of photosynthesis drive cellular respiration inanimals.Discuss Concepts Suppose a garden in your neighborhood is filled with red, white, and blue petunias. Explain the floral colors in terms of which wavelengths of light are absorbed and reflected by the petals.12TYKDiscuss Concepts Like other accessory pigments, the carotenoids extend the range of wavelengths absorbed in photosynthesis. They also protect plants from a potentially lethal process known as photooxidation. This process begins when excitation energy in chlorophylls drives the conversion of oxygen into free radicals, substances that can damage organic compounds and kill cells. When plants that cannot produce carotenoids are grown in light, they bleach white and die. Given this observation, what molecules in the plants are likely to be destroyed by photooxidation?14TYK15TYK16TYKPhotosynthesis directly opposes respiration in determining how plants influence atmospheric CO2 concentrations. When a leaf is in the light, both photosynthesis and respiration are occurring simultaneously. The data in the Table were collected from the leaf of a sagebrush plant that was enclosed in a chamber that measures the rate of CO2 exchange. The same leaf was used to collect the data in Interpret the Data in Chapter 7. Respiration is shown as a negative and photosynthesis as a positive rate of CO2 exchange. The net photosynthesis rate is the amount of CO2 (in micromoles per square meter per second) assimilated by the leaf while respiration is occurring; a positive value indicates more photosynthesis is occurring than respiration. The light exposed to the leaf is quantified as the number of photons in the 400 to 700 nm wavelength, the photosynthetic photon flux density (PPFD); 2,000 mol/m2/s is equivalent to the amount of light occurring at midday in full Sun. Observation Photosynthetic Photon Flux Density (PPFD) (mol/m2/s) Net Photosynthesis (mol/m2/s) 1 2,000 9.1 2 1,500 8.4 3 1,250 8.2 4 1,000 7.4 5 750 6.3 6 500 4.8 7 250 2.2 8 0 -2.0 Why is net photosynthesis negative when PPFD is zero? Looking at the respiration data from Interpret the Data in Chapter 7, at what temperature do you think these data were collected? Source: Data based on unpublished research by Brent Ewers, University of Wyoming.2ITD3ITD4ITDWhat accounts for the specificity of a cellular response to a signal molecule?1SB2SB1SB2SB3SB4SB5SB6SBWhat distinguishes a steroid receptor from a receptor tyrosine kinase receptor or a G-protein-coupled receptor?By what means does a specific steroid hormone result in a specific cellular response?1SBIn signal transduction, which of the following is not a target protein? a. proteins that regulate gene activity b. hormones that activate the receptor c. enzymes of pathways d. transport proteins e. enzymes of cell reactionsWhich of the following could not elicit a signal transduction response? a. a protein kinase b. a virus mimicking a normal signal molecule c. a peptide hormone d. a steroid hormone e. a neurotransmitterA cell that responds to a signaling molecule is distinguished from a cell that does not respond by the fact that it has: a. a cell adhesion molecule. b. cAMP. c. a first messenger molecule. d. a receptor. e. a protein kinase.4TYK5TYKWhich of the following is incorrect about pathways activated by G-proteincoupled receptors? a. The extracellular signaling molecule is the first messenger. b. When activated, plasma membrane-bound G protein canswitch on an effector. c. Second messengers enter the nucleus. d. ATP converts to cAMP to activate protein kinases. e. Protein kinases phosphorylate molecules to change cellularactivity.Which of the following would not inhibit signal transduction? a. Phosphate groups are removed from proteins. b. Endocytosis acts on receptors and their bound signals. c. Receptors and signaling molecules separate. d. Receptors and bound signaling molecules enter lysosomes. e. Autophosphorylation targets the cytoplasmic portion of the receptor.8TYK9TYK10TYKDiscuss Concepts Describe the possible ways in which a G-proteincoupled receptor pathway could become defective and not trigger any cellular responses.Discuss Concepts Is providing extra insulin an effective cure for an individual who has diabetes that is caused by a hereditary defect in the insulin receptor? Why or why not?Discuss Concepts There are molecules called GTP analogs that resemble GTP so closely that they can be bound by G proteins. However, they cannot be hydrolyzed by cellular GTPases. What differences in effect would you expect if you inject GTP or a nonhydrolyzable GTP analog into a liver cell that responds to glucagon?Discuss Concepts Why do you suppose cells evolved internal response mechanisms using molecules that bind GTP instead of ATP?How would you set up an experiment to determine whether a hormone receptor is located on the cell surface or inside the cell?16TYK1ITD2ITD3ITDWhat are the three interrelated systems that contribute to the eukaryotic cell cycle?2SB3SB4SBCompare the chromosome content of daughter cells following mitosis with that of the parent cell before its chromosomes were duplicated.2SB3SBHow does spindle formation differ in animals and plants?2SB1SB2SBWhat is an oncogene? How might an oncogene affect the cell cycle?4SB1SB2SBDuring the cell cycle, the DNA mass of a cell: Decreases during G1. Decreases during metaphase. Increases during the S phase. Increases during G2. Decreases during interphase.A tumor suppressor protein, p21, inhibits Cdk1. The earliest effect p21 on the cell cycle would be to stop the cell cycle at: a. early G1. b. late G1. c. the S phase. d. G2. e. the mitotic prophase.A major difference between hereditary information in eukaryotes and prokaryotes is: a. in prokaryotes, the hereditary information is distributed among individual, linear DNA molecules in the nucleus. b. in eukaryotes, the hereditary information is encoded in a single, circular DNA molecule. c. in prokaryotes, the hereditary information is usually distributed among multiple circular DNA molecules in the cytoplasm. d. in eukaryotes, the hereditary information is distributed among individual, linear DNA molecules in the cytoplasm. e. in eukaryotes, the hereditary information is distributed amoung individual, linear DNA molecules in the nucleus.The major microtubule organizing center of the animal cell is: a. chromosomes, composed of chromatids. b. the centrosome, composed of centrioles. c. the chromatin, composed of chromatids. d. chromosomes, composed of centromere. e. centrioles, composed of centrosome.5TYKWhich of the following statements about mitosis is incorrect? a. Microtubules from the spindle poles attach to the kinetochores on the chromosomes. b. In anaphase, the spindle separates sister chromatids and pulls them apart. c. In metaphase, spindle microtubules align the chromosomes at the spindle midpoint. d. Cytokinesis describes the movement of chromosomes. e. Both the animal cell furrow and the plant cell plate form at their former spindle midpoint.7TYKWhich of the following statements about cell cycle regulators is incorrect? a. The concentrations of cyclins change throughout the cell cycle. b. Cyclins are present in all stages of the cell cycle except S. c. Cyclin-Cdk complexes phosphorylate target proteins. d. Cdks combine with cyclin to move the cycle into mitosis. e. During anaphase of mitosis, cyclin is degraded, allowing mitosis to end.Which of the following is not a characteristic of cancer cells? a. less cytoplasmic volume than normal cells b. an absence of cyclin c. loss of adhesion to other cells d. loss of control of cell division e. loss of normal control of G1/S phase transitionWhich of the following does not accurately characterize bacterial DNA? a. The bacterial chromosome is a closed, circular molecule of DNA. b. Bacterial DNA is organized into nucleosomes. c. The primary DNA molecule of most bacteria is curcular. d. DNA is organized more simply in bacteria than in eukaryotes. e. Positively charges proteins can combine with bacterial DNA.In bacteria: a. several chromosomes undergo mitosis. b. binary fission produces four daughter cells. c. replication begins at the origin (ori), and the DNA strands separate. d. the plasma membrane plays ab important role in separating the duplicated chromosomes into the two daughter cells. e. the daughter cells receive different geneti information from the parent cell.12TYKDiscuss Concepts A cell has 38 chromosomes. After mitosis and cell division, one daughter cell has 39 chromosomes and the other has 37. What might have caused these abnormal chromosome numbers? What effects do you suppose this might have on cell function? Why?14TYK15TYKApply Evolutionary Thinking The genes and proteins involved in cell cycle regulation in prokaryotes and eukaryotes are very different. However, both types of organisms use similar molecular regulatory reactions to coordinate DNA synthesis with cell division. What does this observation mean from an evolutionary perspective?