Biol (I) 1406. Study Guide for First Lecture Exam MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A localized group of organisms that belong to the same species is called a 1) _______ A) family. B) biosystem. C) ecosystem. D) community. E) population. 2) The main source of energy for producers in an ecosystem is 2) _______ A) ATP. B) light energy. C) thermal energy. D) kinetic energy. E) chemical energy. 3) Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic 3) _______ material but do not have their DNA encased within a nuclear envelope? A) archaea B) animal C) fungi D) protists E) plant 4) To understand the chemical basis of inheritance, we must understand the molecular structure of 4) _______ DNA. This is an example of the application of which concept to the study of biology? A) feedback regulation B) the cell theory C) emergent properties D) reductionism E) evolution 5) Which branch of biology is concerned with the naming and classifying of organisms? 5) _______ A) genomics B) informatics C) schematic biology D) taxonomy E) evolution 6) Prokaryotic and eukaryotic cells generally have which of the following features in common? 6) _______ A) linear chromosomes made of DNA and protein B) a cell wall made of cellulose C) a membrane-bounded nucleus D) flagella or cilia that contain microtubules E) ribosomes 7) A water sample from a hot thermal vent contained a single-celled organism that had a cell wall 7) _______ but lacked a nucleus. What is its most likely classification? A) Eukarya B) Archaea C) Fungi D) Animalia E) Protista 8) Prokaryotes are classified as belonging to two different domains. What are the domains? 8) _______ A) Archaea and Monera B) Bacteria and Archaea C) Eukarya and Monera D) Bacteria and Protista E) Bacteria and Eukarya 9) Which of these provides evidence of the common ancestry of all life? A) structure of the nucleus B) ubiquitous use of catalysts by living systems C) structure of chloroplasts D) structure of cilia E) near universality of the genetic code 10) Which of these individuals is likely to be most successful in an evolutionary sense? A) a reproductively sterile individual who never falls ill B) a female who mates with 20 males and produces one offspring that lives to reproduce C) a male who mates with 20 females and fathers one offspring D) an organism that lives 100 years and leaves two offspring, both of whom survive to reproduce E) an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce 11) In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population before they reproduce. Based on your knowledge of natural selection, you would predict that the average height of the human population will A) remain unchanged. B) rapidly increase. C) gradually decline. D) rapidly decline. E) gradually increase. 12) What is the major difference between a kingdom and a domain? A) All prokaryotes belong to one domain. B) Only organisms that produce their own food belong to one of the domains. C) The importance of fungi has led scientists to make them the whole of one domain. D) All eukarya belong to one domain. E) A kingdom can include several subgroups known as domains. 13) Which of the following categories of organisms is least likely to be revised? A) phylum B) class C) kingdom D) species E) order 14) What are archaea? A) Organisms that are adapted to high temperature environments, such as in volcanic springs. B) Bacteria-like organisms that can live only in extreme salt environments. C) Single-celled organisms that are killed by the application of antibiotics at certain concentrations. D) Prokaryotes characterized as extremophiles that share some bacterial and some eukaryotic traits. E) Primitive protist-like creatures possessing fewer than two chromosomes per cell. 15) Similarities and differences among/between life-forms over time are most efficiently recorded by scientists in which field(s) of study? A) paleontology, anatomy, and taxonomy B) paleontology, anatomy, taxonomy, and genetics 9) _______ 10) ______ 11) ______ 12) ______ 13) ______ 14) ______ 15) ______ C) paleontology and anatomy D) paleontology, anatomy, taxonomy, genetics, and ecology E) paleontology 16) Collecting data based on observation is an example of ________; analyzing this data to reach a conclusion is an example of ________ reasoning. A) descriptive science; deductive B) the process of science; deductive C) hypothesis-based science; inductive D) discovery science; inductive E) hypothesis-based science; deductive 17) A controlled experiment is one in which A) there is one group for which the scientist controls all variables. B) the experiment is repeated many times to ensure that the results are accurate. C) there are at least two groups, one differing from the other by two or more variables. D) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. E) there are at least two groups, one of which does not receive the experimental treatment. 18) The application of scientific knowledge for some specific purpose is known as A) pure science. B) technology. C) inductive science. D) deductive science. E) anthropologic science. 19) Which of the following is the best description of a control for an experiment? A) The control group is matched with the experimental group except for the one experimental variable. B) The control group is kept in an unchanging environment. C) The control group is exposed to only one variable rather than several. D) Only the experimental group is tested or measured. E) The control is left alone by the experimenters. 20) All the organisms on your campus make up A) a taxonomic domain. B) an experimental group. C) a community. D) a population. E) an ecosystem. 21) Which of the following is a correct sequence of levels in lifeʹs hierarchy, proceeding downward from an individual animal? A) nervous system, brain, nervous tissue, nerve cell B) brain, organ system, nerve cell, nervous tissue C) organ system, nervous tissue, brain D) organism, organ system, tissue, cell, organ E) organ system, tissue, molecule, cell 22) Protists and bacteria are grouped into different domains because A) protists are photosynthetic. 16) ______ 17) ______ 18) ______ 19) ______ 20) ______ 21) ______ 22) ______ B) bacteria are not made of cells. C) protists eat bacteria. D) bacteria decompose protists. E) protists have a membrane-bounded nucleus, which bacterial cells lack. 23) Which of the following best demonstrates the unity among all organisms? A) descent with modification B) emergent properties C) the structure and function of DNA D) natural selection E) matching DNA nucleotide sequences 24) Which of the following is an example of qualitative data? A) The temperature decreased from 20°C to 15°C. B) The plantʹs height is 25 centimeters (cm). C) The contents of the stomach are mixed every 20 seconds. D) The fish swam in a zigzag motion. E) The six pairs of robins hatched an average of three chicks. 25) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? A) carbon, oxygen, phosphorus, hydrogen B) oxygen, hydrogen, calcium, nitrogen C) carbon, sodium, hydrogen, nitrogen D) carbon, hydrogen, nitrogen, oxygen E) carbon, oxygen, nitrogen, calcium 26) Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants? A) sodium B) nitrogen C) calcium D) iodine E) phosphorus 27) Which of the following statements is false? A) Other than some trace elements, animals are mostly made up of the same elements as plants, in similar proportions. B) Some trace elements are very abundant on Earth. C) Virtually all organisms require the same elements in the same quantities. D) Iron is an example of an element needed by all organisms. E) Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter. 28) What factors are most important in determining which elements are most common in living matter? A) both the relative abundances of the elements and the emergent properties of the compounds made from these elements B) the reactivity of the elements with water C) the chemical stability of the elements D) the emergent properties of the simple compounds made from these elements E) the relative abundances of the elements in Earthʹs crust and atmosphere 23) ______ 24) ______ 25) ______ 26) ______ 27) ______ 28) ______ 29) Why is each element unique and different from other elements in chemical properties? A) Each element has a unique number of protons in its nucleus. B) Each element has different radioactive properties. C) Each element has a unique atomic weight. D) Each element has a unique atomic mass. E) Each element has a unique number of neutrons in its nucleus. 30) Knowing just the atomic mass of an element allows inferences about which of the following? A) the number of protons plus neutrons in the element B) both the number of protons and the chemical properties of the element C) the chemical properties of the element D) the number of protons in the element E) the number of neutrons in the element 31) In what way are elements in the same column of the periodic table the same? A) They have the same number of protons. B) They have the same number of electrons in their valence shell. C) They have the same number of electrons. D) They have the same number of electron shells. E) They have the same number of neutrons. 32) The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen? A) The nitrogen atom has a mass number of approximately 14 daltons and an atomic mass of 7. B) The nitrogen atom has a mass number of 14 and an atomic mass of 7 grams. C) The nitrogen atom has a mass number of 14 and an atomic mass of approximately 14 daltons. D) The nitrogen atom has a mass number of 7 and an atomic number of 14. E) The nitrogen atom has a mass number of approximately 7 daltons and an atomic mass of 14. 33) An atom has 6 electrons in its outer shell. How many unpaired electrons does it have? A) 4 B) 6 C) 2 D) 0 E) 2 or 4 34) The atomic number of neon is 10. Therefore, which of the following is most correct about an atom of neon? A) It is inert. B) It has 8 electrons in its outer electron shell, it is inert, and it has an atomic mass of 10 daltons. C) It has 8 electrons in its outer electron shell. D) It has an atomic mass of 10 daltons. E) It has 8 electrons in its outer electron shell and it is inert. 35) Atoms whose outer electron shells contain 8 electrons tend to A) form hydrogen bonds in aqueous solutions. B) be stable and chemically nonreactive, or inert. C) be both chemically inert and gaseous at room temperature. D) be gaseous at room temperature. E) form ions in aqueous solutions. 29) ______ 30) ______ 31) ______ 32) ______ 33) ______ 34) ______ 35) ______ 36) Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom? A) 1 B) 7 C) 0 D) 3 E) 9 37) A covalent chemical bond is one in which A) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms. B) an electron occupies a hybrid orbital located between the nuclei of two atoms. C) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom. D) outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms. E) electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged. 38) What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen? A) 1 B) 3 C) 6 D) 2 E) 4 39) Which of the following molecules contains the most polar covalent bond? A) H
2O B) H
2 C) CH
4 D) O
2 E) CO
2 40) What is the difference between covalent bonds and ionic bonds? A) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between atoms. B) Covalent bonds involve the transfer of electrons between atoms; ionic bonds involve the sharing of electrons between atoms. C) Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. D) Covalent bonds are formed between atoms to form molecules; ionic bonds are formed between atoms to form compounds. E) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms. 41) The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride? A) MgCl B) MgCl
C) Mg
2Cl2 D) MgCl
E) Mg
2Cl 3 2 42) Which bond or interaction would be difficult to disrupt when compounds are put into water? A) hydrogen bond B) either covalent bonds or ionic bonds C) ionic bond D) van der Waals interaction E) covalent bond 43) Which of the following explains most specifically the attraction of water molecules to one another? A) hydrogen bond B) nonpolar covalent bond C) hydrophobic interaction D) polar covalent bond E) ionic bond 36) ______ 37) ______ 38) ______ 39) ______ 40) ______ 41) ______ 42) ______ 43) ______ 44) Which of the following is not considered to be a weak molecular interaction? A) a van der Waals interaction B) a hydrogen bond C) a covalent bond D) both a hydrogen bond and a covalent bond E) an ionic bond in the presence of water 45) What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms? A) 2 B) 8 C) 4 D) 6 E) 3 46) What coefficients must be placed in the following blanks so that all atoms are accounted for in the products?
C6H12O6 → ____ C2H6O + ____ CO2 A) 3; 1 B) 1; 3 C) 1; 1 D) 1; 2 44) ______ 45) ______ 46) ______ E) 2; 2 47) In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by A) van der Waals interactions. B) polar covalent bonds. C) nonpolar covalent bonds. D) ionic bonds. E) hydrogen bonds. 48) The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called? A) a hydrogen bond B) a covalent bond C) an ionic bond D) a van der Waals interaction E) a hydrophilic bond 49) Which of the following takes place as an ice cube cools a drink? A) A calorie of heat energy is transferred from the ice to the water of the drink. B) Evaporation of the water in the drink increases. C) Kinetic energy in the drink decreases. D) Molecular collisions in the drink increase. E) The specific heat of the water in the drink decreases. 50) Which type of bond must be broken for water to vaporize? A) hydrogen bonds B) both polar covalent bonds and hydrogen bonds C) ionic bonds D) polar covalent bonds E) both hydrogen bonds and ionic bonds 51) Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? A) the release of heat by the formation of hydrogen bonds B) the release of heat by the breaking of hydrogen bonds C) the high surface tension of water D) reactions with other atmospheric compounds 47) ______ 48) ______ 49) ______ 50) ______ 51) ______ E) the change in density when it condenses to form a liquid or solid 52) Why does evaporation of water from a surface cause cooling of the surface? A) The breaking of bonds between water molecules absorbs heat. B) The expansion of water vapor extracts heat from the surface. C) Water molecules absorb heat from the surface in order to acquire enough energy to evaporate. D) The water molecules with the most heat energy evaporate more readily. E) The solute molecules left behind absorb heat. 53) Why does ice float in liquid water? A) The high surface tension of liquid water keeps the ice on top. B) The ionic bonds between the molecules in ice prevent the ice from sinking. C) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. D) The crystalline lattice of ice causes it to be denser than liquid water. E) Ice always has air bubbles that keep it afloat. 54) Hydrophobic substances such as vegetable oil are A) nonpolar substances that have an attraction for water molecules. B) polar substances that repel water molecules. C) polar substances that have an affinity for water. D) charged molecules that hydrogen-bond with water molecules. E) nonpolar substances that repel water molecules. 55) A strong acid like HCl A) ionizes completely in an aqueous solution. B) both ionizes completely in aqueous solutions and is a strong buffer at low pH. C) is a strong buffer at low pH. D) increases the pH when added to an aqueous solution. E) reacts with strong bases to create a buffered solution. 56) Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? A) NaOH B) HCl C) H
2CO3 D) NaCl E) NH
3 57) The bonds that are broken when water vaporizes are A) polar covalent bonds. B) ionic bonds. C) nonpolar covalent bonds. D) hydrogen bonds between water molecules. E) covalent bonds between atoms within water molecules. 58) Which of the following is a hydrophobic material? A) wax B) paper C) pasta D) table salt 59) The element present in all organic molecules is A) nitrogen. B) hydrogen. C) phosphorus. D) oxygen. E) carbon. 52) ______ 53) ______ 54) ______ 55) ______ 56) ______ 57) ______ 58) ______ E) sugar 59) ______ 60) The complexity and variety of organic molecules is due to A) their interaction with water. B) the variety of rare elements in organic molecules. C) their tremendously large sizes. D) the chemical versatility of carbon atoms. E) the fact that they can be synthesized only in living organisms. 61) Differences among organisms are caused by A) differences in the elements that bond with carbon in each organism. B) differences in inorganic compounds present in each organism. C) differences in the types and relative amounts of organic molecules synthesized by each organism. D) large differences in elemental composition from organism to organism. E) differences in the sizes of the organic molecules in each organism. 62) How many electron pairs does carbon share in order to complete its valence shell? A) 2 B) 4 C) 8 D) 1 E) 3 63) A carbon atom is most likely to form what kind of bond(s) with other atoms? A) ionic B) hydrogen C) covalent bonds and hydrogen bonds D) ionic bonds, covalent bonds, and hydrogen bonds E) covalent 64) Which of the following statements best describes the carbon atoms present in a seed-eating bird? A) They are ultimately derived from carbon dioxide. B) They were incorporated into organic molecules by plants, they were processed into sugars through photosynthesis, and they are ultimately derived from carbon dioxide. C) They were processed into sugars through photosynthesis. D) They were incorporated into organic molecules by plants, and they are ultimately derived from carbon dioxide. E) They were incorporated into organic molecules by plants. 65) Which of the following statements best describes the carbon atoms present in a seed-eating bird? A) The carbon atoms ultimately came from the soil. B) Inorganic carbon atoms in the seeds were incorporated into organic molecules by the bird. C) The carbon atoms are ultimately derived from coal. D) The carbon atoms ultimately came from carbon dioxide incorporated into sugars through photosynthesis. E) The carbon atoms ultimately came from simple organic compounds that formed abiotically from inorganic carbon, hydrogen, oxygen, and nitrogen atoms. 66) Why are hydrocarbons insoluble in water? A) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. B) The majority of their bonds are polar covalent carbon-to-hydrogen linkages. C) They are lighter than water. D) They exhibit considerable molecular complexity and diversity. E) They are hydrophilic. 67) Which of the following statements correctly describes cis-trans isomers? 60) ______ 61) ______ 62) ______ 63) ______ 64) ______ 65) ______ 66) ______ 67) ______ A) They have variations in arrangement around a double bond. B) They have the same chemical properties. C) They have an asymmetric carbon that makes them mirror images. D) Their atoms and bonds are arranged in different sequences. E) They have different molecular formulas. 68) Which two functional groups are always found in amino acids? A) ketone and methyl B) amino and sulfhydryl C) carbonyl and amino D) hydroxyl and carboxyl E) carboxyl and amino 69) Amino acids are acids because they always possess which functional group? A) carboxyl B) phosphate C) hydroxyl D) amino 70) Testosterone and estradiol are A) enantiomers of each other. B) soluble in water. C) proteins. D) lipids. E) structural isomers of each other. 71) What is the name of the functional group shown in the figure above? A) ketone B) carbonyl C) aldehyde D) carboxyl 72) Organic chemistry is currently defined as A) the study of hydrocarbons. B) the study of carbon compounds. C) the study of vital forces. D) the study of natural (as opposed to synthetic) compounds. E) the study of compounds made only by living cells. 73) Which of the following hydrocarbons has a double bond in its carbon skeleton? A) C
2H2 B) C
3H8 C) C
2H4 D) CH
4 68) ______ 69) ______ E) carbonyl 70) ______ 71) ______ E) hydroxyl 72) ______ 73) ______ E) C
2H6 74) Which action could produce a carbonyl group? A) the addition of a hydroxyl to a phosphate B) the addition of a thiol to a hydroxyl C) the replacement of the OH of a carboxyl group with hydrogen D) the addition of a sulfhydryl to a carboxyl E) the replacement of the nitrogen of an amine with oxygen 75) Humans and mice differ because A) their cells have some differences in the sequence of nucleotides in their nucleic acids. B) their cells have different small organic molecules. C) their cells make different types of large biological molecules. D) their cells make different types of lipids. E) their cells make different types of proteins. 74) ______ 75) ______ 76) Molecules with which functional groups may form polymers via dehydration reactions? A) either carbonyl or carboxyl groups B) carbonyl groups C) hydroxyl groups D) carboxyl groups E) either hydroxyl or carboxyl groups 77) Polysaccharides, triacylglycerides, and proteins are similar in that they A) are synthesized from monomers by the process of hydrolysis. B) are synthesized from subunits by dehydration reactions. C) all contain nitrogen in their monomer building blocks. D) are decomposed into their subunits by dehydration reactions. E) are synthesized as a result of peptide bond formation between monomers. Use the following information to answer the questions below.
76) ______ 77) ______ Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each synthesized from four nucleotides.
78) Which class of biological polymer has the greatest functional variety? A) polysaccharides B) RNA C) DNA D) proteins 79) Which of the following categories includes all others in the list? A) monosaccharide B) disaccharide C) polysaccharide D) carbohydrate E) starch 80) The structural level of a protein least affected by a disruption in hydrogen bonding is the A) All structural levels are equally affected. B) primary level. C) secondary level. D) tertiary level. E) quaternary level. 81) Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A) The pyrimidines would be separated from the deoxyribose sugars. B) The purines would be separated from the deoxyribose sugars. C) The phosphodiester linkages of the polynucleotide backbone would be broken. D) All bases would be separated from the deoxyribose sugars. E) The two strands of the double helix would separate. 82) The molecular formula for glucose is C
6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A) C
60H102O51 B) C
6H12O6 C) C
60H111O51 D) C
60H100O50 78) ______ 79) ______ 80) ______ 81) ______ 82) ______ E) C
60H120O60 83) Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A) 5ʹ-AGCT-3ʹ with 5ʹ-TCGA-3ʹ B) 5ʹ-ATGC-3ʹ with 5ʹ-GCAT-3ʹ C) 5ʹ-purine-pyrimidine-purine-pyrimidine-3ʹ with 3ʹ-purine-pyrimidine-purine-pyrimidine-5ʹ D) 5ʹ-GCGC-3ʹ with 5ʹ-TATA-3ʹ E) All of these pairs are correct. 84) What aspects of protein structure are stabilized or assisted by hydrogen bonds? A) tertiary structure B) quaternary structure C) secondary structure D) secondary, tertiary, and quaternary structures, but not primary structure E) primary structure 85) Which bonds are created during the formation of the primary structure of a protein? A) peptide bonds, hydrogen bonds, and disulfide bonds B) hydrogen bonds C) peptide bonds D) disulfide bonds E) phosphodiester bonds 86) What maintains the secondary structure of a protein? A) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond B) peptide bonds C) disulfide bonds D) hydrogen bonds between the R groups E) hydrophobic interactions 87) Which level of protein structure do the α helix and the β pleated sheet represent? A) secondary B) primary C) tertiary D) primary, secondary, tertiary, and quaternary E) quaternary 88) The tertiary structure of a protein is the A) unique three-dimensional shape of the fully folded polypeptide. B) bonding together of several polypeptide chains by weak bonds. C) overall protein structure resulting from the aggregation of two or more polypeptide subunits. D) order in which amino acids are joined in a polypeptide chain. E) organization of a polypeptide chain into an α helix or β pleated sheet. 89) What type of covalent bond between amino acid side chains (R groups) functions in maintaining a polypeptideʹs specific three-dimensional shape? A) hydrophobic interaction B) van der Waals interaction C) hydrogen bond 83) ______ 84) ______ 85) ______ 86) ______ 87) ______ 88) ______ 89) ______ D) ionic bond E) disulfide bond 90) At which level of protein structure are interactions between the side chains (R groups) most important? A) secondary B) tertiary C) quaternary D) primary E) all of the above 91) One of the primary functions of RNA molecules is to A) act as a pattern or blueprint to form DNA. B) transmit genetic information to offspring. C) make a copy of itself, thus ensuring genetic continuity. D) function in the synthesis of proteins. E) form the genes of higher organisms. 92) Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base, a phosphate group, and a pentose sugar B) a pentose sugar and a purine or pyrimidine C) a phosphate group and an adenine or uracil D) a nitrogenous base and a pentose sugar E) a nitrogenous base and a phosphate group 93) Which of the following are nitrogenous bases of the pyrimidine type? A) cytosine and uracil B) thymine and guanine C) adenine and thymine D) ribose and deoxyribose E) guanine and adenine 94) Which of the following are nitrogenous bases of the purine type? A) uracil and cytosine B) cytosine and guanine C) adenine and thymine D) thymine and uracil E) guanine and adenine 95) What is the structural feature that allows DNA to replicate? A) three-component structure of the nucleotides B) disulfide bonding (bridging) of the two helixes C) twisting of the molecule to form an α helix D) complementary pairing of the nitrogenous bases E) sugar-phosphate backbone 96) Which of these molecules is not formed by dehydration reactions? A) amylose B) fatty acids C) protein D) disaccharides E) DNA 90) ______ 91) ______ 92) ______ 93) ______ 94) ______ 95) ______ 96) ______ 97) Which of these classes of biological molecules consist of both small molecules and macromolecular polymers? A) lipids, carbohydrates, proteins, and nucleic acids all consist of only macromolecular polymers B) lipids C) proteins D) carbohydrates E) nucleic acids 98) Which of the following is not a polymer? A) cellulose B) glucose C) chitin D) DNA E) starch 99) What is the chemical reaction mechanism by which cells make polymers from monomers? A) the formation of disulfide bridges between monomers B) ionic bonding of monomers C) hydrolysis D) dehydration reactions E) phosphodiester linkages 100) Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Hydrolysis creates monomers, and dehydration reactions break down polymers. B) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers. C) Dehydration reactions eliminate water from lipid membranes, and hydrolysis makes lipid membranes water permeable. D) Dehydration reactions can occur only after hydrolysis. E) Dehydration reactions ionize water molecules and add hydroxyl groups to polymers; hydrolysis reactions release hydroxyl groups from polymers. 101) Which of the following polymers contain nitrogen? A) amylopectin B) glycogen C) starch D) chitin E) cellulose 102) The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down? A) cellulose B) glycogen, cellulose, and chitin C) chitin D) glycogen and chitin only E) glycogen 103) On food packages, to what does the term insoluble fiber refer? A) cellulose B) polypeptides C) chitin D) starch E) amylopectin 97) ______ 98) ______ 99) ______ 100) _____ 101) _____ 102) _____ 103) _____ 104) A molecule with the chemical formula C
6H12O6 is probably a 104) _____ A) monosaccharide B) carbohydrate. C) carbohydrate and monosaccharide only. D) carbohydrate and lipid only. E) lipid. 105) Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? A) as a pentose B) as a polysaccharide C) as a monosaccharide D) as a disaccharide E) as a hexose 106) All of the following are polysaccharides except A) lactose. B) amylopectin. C) glycogen. D) chitin. E) cellulose. 107) Which of the following is true of cellulose? A) It is digestible by bacteria in the human gut. B) It is a polymer composed of enantiomers of glucose, it is a storage polysaccharide for energy in plant cells, it is digestible by bacteria in the human gut, and it is a major structural component of plant cell walls. C) It is a major structural component of plant cell walls. D) It is a storage polysaccharide for energy in plant cells. E) It is a polymer composed of enantiomers of glucose. 108) Humans can digest starch but not cellulose because A) humans harbor starch-digesting bacteria in the digestive tract. B) humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose. C) the monomer of starch is glucose, while the monomer of cellulose is galactose. D) the monomer of starch is glucose, while the monomer of cellulose is glucose with a nitrogen-containing group. E) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose. 109) Which of the following statements concerning saturated fats is not true? A) They have multiple double bonds in the carbon chains of their fatty acids. B) They contain more hydrogen than unsaturated fats having the same number of carbon atoms. C) They generally solidify at room temperature. D) They are more common in animals than in plants. E) They are one of several factors that contribute to atherosclerosis. 110) A molecule with the formula C
18H36O2 is probably a A) protein. B) nucleic acid. 105) _____ 106) _____ 107) _____ 108) _____ 109) _____ 110) _____ C) fatty acid. D) hydrocarbon. E) carbohydrate. 111) Which of the following statements is true for the class of biological molecules known as lipids? A) They are made by dehydration reactions. B) They are insoluble in water. C) They contain less energy than proteins and carbohydrates. D) They contain nitrogen. E) They are made from glycerol, fatty acids, and phosphate. 112) The label on a container of margarine lists ʺhydrogenated vegetable oilʺ as the major ingredient. What is the result of adding hydrogens to vegetable oil? A) The hydrogenated vegetable oil has fewer trans fatty acids. B) The hydrogenated vegetable oil has more ʺkinksʺ in the fatty acid chains. C) The hydrogenated vegetable oil stays solid at room temperature. D) The hydrogenated vegetable oil has a lower melting point. E) The hydrogenated vegetable oil is less likely to clog arteries. 113) Which of the following is true regarding saturated fatty acids? A) They have double bonds between carbon atoms of the fatty acids. B) They are usually produced by plants. C) They are usually liquid at room temperature. D) They are the predominant fatty acid in corn oil. E) They are the principal molecules in lard and butter. 114) Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement? A) a contractile protein B) a steroid C) cellulose D) an enzyme E) DNA 115) Why are human sex hormones considered to be lipids? A) They are hydrophilic compounds. B) They are not soluble in water. C) They contribute to atherosclerosis. D) They are essential components of cell membranes. E) They are made of fatty acids. 116) All of the following contain amino acids except A) cholesterol. B) insulin. C) antibodies. D) enzymes. E) hemoglobin. 117) The bonding of two amino acid molecules to form a larger molecule requires A) the release of a carbon dioxide molecule. B) the addition of a nitrogen atom. C) the release of a water molecule. 111) _____ 112) _____ 113) _____ 114) _____ 115) _____ 116) _____ 117) _____ D) the release of a nitrous oxide molecule. E) the addition of a water molecule. 118) The bonding of two amino acid molecules to form a larger molecule requires which of the following? A) addition of a water molecule B) both removal of a water molecule and formation of a hydrogen bond C) formation of a glycosidic bond D) removal of a water molecule E) formation of a hydrogen bond 118) _____ 1) E 2) B 3) A 4) D 5) D 6) E 7) B 8) B 9) E 10) E 11) C 12) D 13) D 14) D 15) D 16) D 17) E 18) B 19) A 20) C 21) A 22) E 23) C 24) D 25) D 26) D 27) C 28) A 29) A 30) A 31) B 32) C 33) C 34) E 35) C 36) A 37) D 38) D 39) A 40) E 41) D 42) E 43) A 44) C 45) D 46) E 47) B 48) A 49) C 50) A 51) A 52) D 53) C 54) E 55) A 56) A 57) D 58) A 59) E 60) D 61) C 62) B 63) E 64) B 65) D 66) A 67) A 68) E 69) A 70) E 71) D 72) B 73) C 74) C 75) A 76) E 77) B 78) D 79) D 80) B 81) C 82) A 83) B 84) D 85) C 86) A 87) A 88) A 89) E 90) B 91) D 92) A 93) A 94) E 95) D 96) B 97) D 98) B 99) D 100) B 101) D 102) E 103) A 104) C 105) D 106) A 107) C 108) E 109) A 110) C 111) B 112) C 113) E 114) B 115) B 116) A 117) C 118) D