Bartleby Sitemap - Textbook Solutions
All Textbook Solutions for Biology (MindTap Course List)
Describe five basic themes of biology.Why are information transmission, energy transfer, and evolution considered basic to life?CONNECT What are some ways in which an organism is dependent on other biological systems?2LO1CPredict What would be the consequences to an organism if its homeostatic mechanisms failed? Explain your answer3LOWhat are the levels of organization within an organism?PREDICT At which level do you think more biological systems would be interacting: organism, population, or ecosystem? Justify your answer.Summarize the importance of information transfer within and between living systems, giving specific examples.What is the function of DNA?How does a nervous system transmit information?Summarize the flow of energy through ecosystems and contrast the roles of producers, consumers, and decomposers.Predict What components do you think a forest ecosystem might include?Connect In what ways do consumers depend on producers? on decomposers? Include energy considerations in your answer.Demonstrate the binomial system of nomenclature by using specific examples and classify an organism (such as a human) in its domain, kingdom, phylum, class, order, family, genus, and species.7LO8LO9LOThe scientific name for the African rock python is Python sebae. Which name indicates its genus?2CHow might you explain the sharp claws and teeth of tigers in terms of natural selection?Design a study to test a given hypothesis, using the procedure and terminology of the scientific method.Compare the reductionist and systems approaches to biological research.What are the characteristics of a good hypothesis?2CCONNECT In what ways does systems biology depend on reductionism?1TYU2TYU3TYUFungi are assigned to domain (a) Protista (b) Archaea (c) Bacteria (d) Eukarya (e) PlantaeThe scientific name for corn is Zea mays. Zea is the (a) specific epithet (b) genus (c) class (d) kingdom (e) phylumDarwin suggested that evolution takes place by (a) mutation (b) changes in the individuals of a species (c) natural selection (d) interaction of hormones during competition for resources (e) homeostatic responses to each change in the environmentIdeally, an experimental group differs from a control group (a) only with respect to the hypothesis being tested (b) because its subjects are more reliable (c) in that it is less subject to bias (d) in that it is less vulnerable to sampling error (e) only with respect to the variable being studied8TYUVISUALIZE Draw a simple cladogram illustrating the relationships among the following: Common ancestor of all organisms, domain Eukarya, domain Bacteria, domain Archaea. To which domain do the organisms informally known as protists belong? To which domain do you belong? Refer to Figure 1-11 to check your answer.predict What would happen if a homeostatic mechanism failed? Give an example using a homeostatic mechanism at work in your body (other than the regulation of glucose cited in the chapter).What are some characteristics of a good hypothesis? Give an example.PREDICT Make a prediction and devise a suitably controlled experiment to test each of the following hypotheses: (a) A type of mold found in your garden produces an effective antibiotic. (b) The growth rate of a bean seedling is affected by temperature. (c) Estrogen alleviates symptoms of Alzheimers disease in elderly women.13TYUINTERPRET DATA Compare the two graphs in Figure 1-17. What information does the second graph illustrate? What possible explanation can you give for the differences shown in the two graphs? (a) Number of chimpanzees who successfully employed specific method of tool use. (b) Number of chimpanzees who successfully employed learned method of tool use two months later. Figure 1-17 An experiment testing learning in chimpanzee populations In the photo, wild chimpanzees are shown observing a member of their group using a tool.Evolution Link In what ways does evolution depend on transfer of information? In what ways does transfer of information depend on evolution?EVOLUTION LINK How might an understanding of evolutionary processes help a biologist doing research in (a) the development of a new antibiotic to replace one to which bacteria have become resistant? (b) conservation of a specific plant in a rain forest?SCIENCE, TECHNOLOGY, AND SOCIETY In the future, gene technology may make it possible for parents to produce children with athletic ability, artistic talent, or high IQ. Do you have any ethical concerns about these possibilities? If so, where and how would you draw the line?1LOCompare the physical properties (mass and charge) and locations of electrons, protons, and neutrons. Distinguish between the atomic number and the mass number of an atom.3LO1CWhat is a radioisotope? What are some ways radioisotopes are used in biological research?3C4LO5LO6LOWhat enables a radioisotope to substitute for an ordinary (nonradioactive) atom of the same element molecule?Which kind of chemical formula provides the most information?3CDistinguish among covalent bonds, ionic bonds, hydrogen bonds, and van der Waals interactions. Compare them in terms of the mechanisms by which they form and their relative strengths.1C2C3C4C8LOIn what form is energy transferred in a redox reaction?Explain how hydrogen bonds between adjacent water molecules govern many of the properties of water.1CWhat are some properties of water that result from hydrogen bonding? How do these properties contribute to the role of water as an essential component of organisms?How can weak forces, such as hydrogen bonds, have significant effects in organisms?Contrast acids and bases, and discuss their properties.Convert the hydrogen ion concentration (moles per liter) of a solution to a pH value and describe how buffers help minimize changes in pH.Describe the composition of a salt and explain the ways in which salts are important in organisms.1C2C3C4CTest Your Understanding Know and Comprehend 1. Which of the following elements is mismatched with its properties or function? (a) carbonforms the backbone of organic compounds (b) nitrogencomponent of proteins (c) hydrogenvery electronegative (d) oxygencan participate in hydrogen bonding (e) all of the above are correctly matched2TYU3TYUTest Your Understanding Know and Comprehend 4. 11H and 13H have (a) different chemical properties because they have different atomic numbers (b) the same chemical properties because they have the same number of valence electrons (c) different chemical properties because they differ in their number of protons and electrons (d) the same chemical properties because they have the same atomic mass (e) the same chemical properties because they have the same number of protons, electrons, and neutronsTest Your Understanding Know and Comprehend 5. The orbitals composing an atoms valence electron shell (a) are arranged as concentric spheres (b) contain the atoms least energetic electrons (c) may change shape when covalent bonds are formed (d) never contain more than one electron each (e) more than one of the preceding is correctTest Your Understanding Know and Comprehend 6. Which of the following bonds and properties are correctly matched? (a) ionic bonds; are strong only if the participating ions are hydrated (b) hydrogen bonds; are responsible for bonding oxygen and hydrogen to form a single water molecule (c) polar covalent bonds; can occur between two atoms of the same element (d) covalent bonds; may be single, double, or triple (e) hydrogen bonds; are stronger than covalent bondsTest Your Understanding Know and Comprehend 7. In a redox reaction, (a) energy is transferred from a reducing agent to an oxidizing agent (b) a reducing agent becomes oxidized as it accepts an electron (c) an oxidizing agent accepts a proton (d) a reducing agent donates a proton (e) the electrons in an atom move from its valence shell to a shell closer to its nucleusTest Your Understanding Know and Comprehend 8. Water has a high specific heat because (a) hydrogen bonds must be broken to raise its temperature (b) hydrogen bonds must be formed to raise its temperature (c) it is a poor insulator (d) it has low density considering the size of the molecule (e) it can ionize9TYU10TYUTest Your Understanding Know and Comprehend 11. Which of the following cannot function as a buffer? (a) phosphoric acid, a weak acid (b) sodium hydroxide, a strong base (c) sodium chloride, a salt that ionizes completely (d) a and c (e) b and c12TYU13TYUTest Your Understanding Apply and Analyze 14. Consider the following reaction (in water): HCl H+ + Cl Name the reactant(s) and product(s). Does the expression indicate that the reaction is reversible? Could HCl be used as a buffer?15TYU16TYUTest Your Understanding Evaluate and Synthesize 17. EVOLUTION LINK Scientists have proposed various initiatives to detect water vapor, as well as oxygen and carbondioxide, in the atmospheres of distant planets. Which of these biosignatures (chemical markers that are evidence for life) would you consider the most fundamental indicator that life could have evolved on these planets? Explain your reasoning.Describe the properties of carbon that make it the central component of organic compounds.Define the term isomer and distinguish among the three principal isomer types.Identify the major functional groups present in organic compounds and describe their properties.Explain the relationship between polymers and macromolecules.What are some of the ways that the features of carbon-to-carbon bonds influence the stability and 3-D structure of organic molecules?2C3C4C5CDistinguish among monosaccharides, disaccharides, and polysaccharides; compare storage polysaccharides with structural polysaccharides.VISUALIZE Draw simple sketches comparing the structures of storage polysaccharides, such as starch and glycogen, with those of structural polysaccharides, such as cellulose and chitin. State how hydrogen bonding stabilizes these structures.Distinguish among fats, phospholipids, and steroids, and describe the composition, characteristics, and biological functions of each.1CExplain why the structure of phospholipids enables them to form lipid bilayers in aqueous conditions, whereas triacylglycerols and diacylglycerols do not.Give an overall description of the structure and functions of proteins.8LODistinguish among the four levels of organization of protein molecules.1C2CDescribe the components of a nucleotide. Name some nucleic acids and nucleotides, and discuss the importance of these compounds in living organisms.VISUALIZE Sketch a pyrimidine nucleotide subunit that would be found only in RNA. Circle and label the three components that make up this type of nucleotide. Explain what changes in the functional groups of this subunit would have to occur for it to be found in a DNA molecule.Compare the functions and chemical compositions of the major groups of organic compounds: carbohydrates, lipids, proteins, and nucleic acids.How can you distinguish a pentose sugar from a hexose sugar? a disaccharide from a sterol? an amino acid from a monosaccharide? a phospholipid from a triacylglycerol? a protein from a polysaccharide? a nucleic acid from a protein?1TYUVISUALIZE The structures depicted are (a) enantiomers (b) different views of the same molecule (c) geometric (cistrans) isomers (d) both geometric isomers and enantiomers (e) structural isomers3TYUThe synthetic process by which monomers are covalently linked is (a) hydrolysis (b) isomerization (c) condensation (d) glycosidic linkage (e) ester linkageA monosaccharide designated as an aldehyde sugar contains (a) a terminal carboxyl group (b) an internal carboxyl group (c) a terminal carbonyl group (d) an internal carbonyl group (e) a terminal carboxyl group and an internal carbonyl groupStructural polysaccharides typically (a) have extensive hydrogen bonding between adjacent molecules (b) are much more hydrophilic than storage polysaccharides (c) have much stronger covalent bonds than do storage polysaccharides (d) consist of alternating -glucose and -glucose subunits (e) form helical structures in the cellSaturated fatty acids are so named because they are saturated with (a) hydrogen (b) water (c) hydroxyl groups (d) glycerol (e) double bondsFatty acids in phospholipids and triacylglycerols interact with one another by (a) disulfide bridges (b) van der Waals interactions (c) covalent bonds (d) hydrogen bonds (e) fatty acids do not interact with one anotherWhich of the following levels of protein structure may be affected by hydrogen bonding? (a) primary and secondary (b) primary and tertiary (c) secondary, tertiary, and quaternary (d) primary, secondary, and tertiary (e) primary, secondary, tertiary, and quaternaryWhich of the following associations between R groups are the strongest? (a) hydrophobic interactions (b) hydrogen bonds (c) ionic bonds (d) peptide bonds (e) disulfide bridgesEach phosphodiester linkage in DNA or RNA includes a phosphate joined by covalent bonds to (a) two bases (b) two sugars (c) two additional phosphates (d) a sugar, a base, and a phosphate (e) a sugar and a basePREDICT Do any of the amino acid side groups shown below have the potential to form an ionic bond with any of the other side groups shown? If so, which pair(s) could form such an association? (a)CH3 (b)CH2 COO (c)CH2 CH2 NH3+ (d)CH2 CH2 COO (e)CH2 OHPREDICT Like oxygen, sulfur forms two covalent bonds. However, sulfur is far less electronegative. In fact, it is approximately as electronegative as carbon. How would the properties of the various classes of biological molecules be altered if you were to replace all the oxygen atoms with sulfur atoms?Hydrogen bonds and van der Waals interactions are much weaker than covalent bonds, yet they are vital to organisms. Explain, providing some specific examples.EVOLUTION LINK In what ways are all species alike biochemically? Identify some ways in which species may differ from one another biochemically. What do these similarities and differences suggest about the history of life on Earth?EVOLUTION LINK The total number of possible amino acid sequences in a polypeptide chain is staggering. Given that there are 20 amino acids, potentially there could be 20100 different amino acid sequences just for polypeptides only 100 amino acids in length. However, the actual number of different polypeptides occurring in organisms is only a tiny fraction of this potential. What insight does this finding provide into the evolutionary process?EVOLUTION LINK Each amino acid could potentially exist as one of two possible enantiomers, known as the D-form and the L-form (based on the arrangement of the groups attached to the asymmetric carbon). However, in all organisms, only L-amino acids are found in proteins. What does this suggest about the evolution of proteins?1LORelate the organizational similarities of all cells to the need to conduct essential life functions.3LO1CPREDICT Could a cell function if it were not enclosed by a selective barrier (i.e., a plasma membrane)?3CWhat convenient form of chemical energy is used by all cells?Why is the relationship between surface area and volume of a cell important in determining cell size limits?4LO1CWhat are the advantages of using many varied methods to connect structure and function in cells? Give some examples.5LO6LOWhat features do prokaryotic and eukaryotic cells have in common?2CIn what ways do membrane-enclosed organelles facilitate cell metabolism?7LO1CIn what ways is transport through the nuclear pores selective?3CDistinguish between smooth and rough endoplasmic reticulum in terms of both structure and function.Trace the path of proteins synthesized in the rough endoplasmic reticulum as they are processed, modified, and sorted by the Golgi complex and then transported to specific destinations.Compare the functions of lysosomes, vacuoles, and peroxisomes.11LO1C2C3C4C12LORelate the structure of cilia and flagella to their functions.In what ways do the functions of the cytoskeleton differ from those of the endomembrane system?How are microfilaments and microtubules similar? How are they different?3CCompare the roles of the glycocalyx, extracellular matrix, and cell wall.1C2CWhich of the following is the most fundamental feature that enables the cell to function as a distinct entity, separate from its environment? (a) nucleus (b) ribosomes (c) nucleic acids (d) plasma membrane (e) protein2TYUKnow and Comprehend 3. Which of the following would not be found in prokaryotic cells? (a) cell wall (b) ribosomes (c) plasma membrane (d) nucleus (e) propeller-like flagellumWhich of the following would you expect to find passing through a nuclear pore? (a) ribosome subunit (b) ribosomal protein (c) messenger RNA (d) water (e) all of the precedingSelect the sequence that most accurately describes glycoprotein processing in the eukaryotic cell. 1. cis face of Golgi 2. smooth ER 3. rough ER 4. trans face of Golgi 5. transport vesicle (a) 1, 2, 3, 4, 5 (b) 1, 4, 5, 3, 2 (c) 2, 3, 4, 5, 1 (d) 3, 5, 1, 4 (e) 2, 5, 1, 46TYUMicrotubules (a) have constant diameters, but vary in length (b) vary in diameter, but are constant in length (c) vary in both length and diameter (d) are constant in both length and diameterAll of the following are true of integrins except (a) they are receptor proteins (b) they help organize the cytoskeleton (c) they are part of the ECM (d) they are important in cell signaling (e) they are located in the plasma membrane9TYU10TYUWhy does a eukaryotic cell need both membranous organelles and fibrous cytoskeletal components? Justify your answer.INTERPRET data An investigator has isolated two mutant strains of yeast that fail to secrete a short polypeptide. She fractionated the cells and compared the concentrations of this polypeptide in the different cellular fractions with those found in normal cells. What point in the secretory pathway would you expect would be defective for mutant a and mutant b?EVOLUTION LINK What types of similarities in cell structure and function tell biologists about the common origin of organisms? Explain.14TYU1LO2LO3LO4LOWhat molecules are responsible for the physical properties of a cell membrane?2C3C5LO1CWhat roles do membrane proteins play in cell interactions?Describe the importance of selectively permeable membranes and compare the functions of carrier proteins and channel proteins.1C2C3C7LOLEARNING O9BJECTIVES 8Define osmosis and solve simple problems involving osmosis; for example, predict whether cells will swell or shrink under various osmotic conditions.PREDICT What would happen if a plan cell were placed in a isotonic solution? a hypertonic environment? a hypotonic environment? How would you modify your predictions for an animal cell?What is the immediate source of energy for simple diffusion? for facilitated diffusion?3C9LO1CWhat is the immediate energy source for cotransport?10LOIn what ways are exocytosis and endocytosis similar?How are the processes of phagocytosis and pinocytosis different?What is the sequence of events in receptor-mediated endocytosis?Compare the structures and functions of anchoring junctions, tight junctions, gap junctions, and plasmodesmata.1C2CTest Your Understanding 1.Transmembrane proteins (a) are peripheral proteins (b) receptor proteins (c) extend completely through the membrane (d) extend along the surface of the membrane (e) are secreted from the cellTest Your Understanding 2.Which of the following is not a function of the plasma membrane? (a) trasnports materials (b) help structurally link cells (c) has receptors thatr relay signals (d) anchors the cell to the extracellular matrix (e) manufactures proteinsTest Your Understanding 3.ABC transporters (a) use the energy of ATP hydrolysis to transport certain ions and sugars (b) are important in facilitated diffusion of certain ions (c) are a small group of channel proteins (d) are found mainly in plant cell membranesTest Your Understanding 4.When plant cells are in a hypotonic medium, they (a) undergo plasmolysis (b) build up turgor pressure (c) wilt (d) decrease pinocytosis (e) lose water to the environmentTest Your Understanding 5.Which of the following processes requires the cell to expend metabolic energy directly (e.g., from ATP)? (a) osmosis (b) facilitated diffusion (c) all forms of carrier-mediated transport (d) active transport (d) active transport (e) simple diffusionTest Your Understanding 6.Electrochemical gradients (a) power simple diffusion (b) are established by pinocytosis (c) are necessary for transport by aquaporins (d) are established by concentration gradients (e) are a result of both an electric charge difference and a concentration difference between the two sides of the membraneTest Your Understanding 7.In cotransport (indirect active transport) (a) a uniporter moves a solute across a membrane against its concentration gradient (b) the move of one solute down its concentration gradient provides energy for transport of some other solute up its concentration gradient (c) a channel protein moves ions by facilitated diffusion (d) osmosis powers the movement of ions against their concentration gradient (e) sodium is directly transported in one direction, and potassium is indirectly transported in the same direction8TYU9TYUTest Your Understanding 10.INTERPRET DATA GLUT 4 is a glucose transporter that functions in adipose (fat) cell plasma membranes. An analysis of adipose cells exposed to insulin showed that a single cell could import glucose at a maximum rate of about 1108 molecules/second. Under the same conditions, unstimulated cells could only transport a maximum of about 1107 molecules/second. What does this finding tell you about the relative number of GLUT 4 transporters functioning in the plasma membranes of stimulated versus unstimulated cells?11TYUTest Your Understanding 12.EVOLUTION LINK Explain to your roommate why the evolution of biological membranes was an essential step in the origin of life. Give arguments supporting (or challenging) this hypothesis.13TYUDescribe the four main processes essential for cells to communicate.What is the sequence of events that takes place in cell signaling?2CCompare three types of signaling molecules: neurotransmitters, hormones, and local regulators.1C2C3CIdentify mechanisms that make reception a highly specific process.4LO1C2C3C4C5LOTrace the sequence of events in signal transduction for each of the following second messengers: cyclic AMP, inositol trisphosphate (IP3), diacylglycerol (DAG), and calcium ions.How is an extracellular signal converted to an intracellular signal in signal transduction? Give a specific example.2C3C7LO8LO1C2C3CCite evidence supporting a long evolutionary history for cell signaling molecules.1CDuring signal transduction (a) the cell converts an extracellular signal into an intracellular signal that leads to a change in some cell process (b) a signaling molecule directly activates or represses several genes (c) each enzyme catalyzes production of one molecule of product (d) enzymes in the signal cascade remain active until the last component of the pathway alters a cellular process (e) the signal is terminated by cyclic AMPWhen a signaling molecule binds with a receptor, (a) G proteins are inactivated (b) a third messenger is activated (c) cell signaling is terminated (d) cAMP is produced by the receptor (e) the receptor becomes activatedG proteinlinked receptors (a) inactivate G proteins (b) activate first messengers (c) consist of 18 transmembrane alpha helices (d) have a tail that extends into the cytosol with a binding site for a G protein (e) are located in the cytoplasm or nucleus4TYU5TYUCalcium ions (a) can act as second messengers (b) split calmodulin (c) are kept at higher concentration in the cytosol than in the extracellular fluid (d) are produced in the ER by protein kinases and protein phosphatases (e) typically terminate signaling cascadesWhen growth hormone binds to an enzyme-linked receptor, (a) G proteins are amplified into a cascade of molecules (b) the enzyme portion of the receptor becomes dephosphorylated (c) the receptor becomes activated and phosphorylates signaling proteins in the cell (d) an ion channel is opened (e) an immediate signal is sent into the nucleus, and specific genes are activated or inhibitedScaffold proteins (a) release kinases and phosphatases into the extracellular fluid (b) bind G proteins to cell membranes (c) increase accuracy but slow signaling cascades (d) organize groups of intracellular signaling molecules into signaling complexes (e) are transcription factors found mainly in plant cells9TYU10TYUMore than 500 genes have been identified in the human genome that code for protein kinases. What does such identification imply regarding the role of protein kinases in cellular functions? Explain your answer.12TYU13TYUEVOLUTION LINK Cell signaling in plant and animal cells is similar in some ways and different in others. Offer one or more hypotheses for these similarities and differences, and cite specific examples.EVOLUTION LINK Some of the same G proteinlinked receptors and signal transduction pathways found in plants and animals have been identified in fungi and algae. What does that suggest about the evolution of these molecules? What does it suggest about these molecules and pathways?16TYUDefine energy, emphasizing how it is related to work and to heat.Use examples to contrast potential energy and kinetic energy.1C3LO1CLife is sometimes described as a constant struggle against the second law of thermodynamics. How do organisms succeed in this struggle without violating the second law?4LO5LO6LO1C2CExplain how the chemical structure of ATP allows it to transfer a phosphate group and discuss the central role of ATP in the overall energy metabolism of the cell.1C2CRelate the transfer of electrons (or hydrogen atoms) to the transfer of energy.PREDICT Which has the most energy, the oxidized form of a substance or its reduced form? What is responsible for the difference?Explain how an enzyme lowers the required energy of activation for a reaction.Describe specific ways enzymes are regulated.1CHow does the function of the active site of an enzyme differ from that of an allosteric site?How are temperature and pH optima of an enzyme related to its structure and function?4CWhich of the following can do work in a cell? (a) entropy (b) heat (c) heat energy (d) all the preceding (e) none of the preceding2TYU3TYUTest Your Understanding 4. Diffusion is an (a) endergonic process because free energy increases (b) endergonic process because free energy decreases (c) exergonic process because entropy increases (d) exergonic process because entropy decreases (e) more than one of the preceding options are true5TYU6TYU7TYUTest Your Understanding 8. Induced fit means that when a substrate binds to an enzymes active site, (a) it fits perfectly, like a key in a lock (b) the substrate and enzyme undergo conformational changes (c) a site other than the active site undergoes a conformational change (d) the substrate and the enzyme become irreversibly bound to each other (e) c and d9TYU10TYUPREDICT In the following reaction series, which enzyme(s) is/are most likely to have an allosteric site to which the end product E binds? (a) enzyme 1 (b) enzyme 2 (c) enzyme 3 (d) enzyme 4 (e) enzymes 3 and 4Test Your Understanding 12. EVOLUTION link All organisms use ATP/ADP as central links between exergonic and endergonic reactions. What does that suggest about the evolution of energy metabolism?EVOLUTION LINK Some have argued that evolution is impossible because the second law of thermodynamics states that entropy always increases; therefore natural processes cannot give rise to greater complexity. In what ways is this statement a misunderstanding of the laws of thermodynamics?14TYU