BIO 171 M.C.
A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance? A) It is a strong acid that dissociates completely in water. B) It is a strong base that dissociates completely in water. C) It is a weak acid. D) It is a weak base.
Answer: A
A covalent bond is likely to be polar when _____. A) one of the atoms sharing electrons is more electronegative than the other atom B) the two atoms sharing electrons are equally electronegative C) carbon is one of the two atoms sharing electrons D) the two atoms sharing electrons are the same elements
Answer: A
A strong acid like HCl _____. A) dissociates completely in an aqueous solution B) increases the pH when added to an aqueous solution C) reacts with strong bases to create a buffered solution D) is a strong buffer at low pH
Answer: A
An atom has four electrons in its valence shell. What types of covalent bonds is it capable of forming? A) single, double, or triple B) single and double only C) single bonds only D) double bonds only
Answer: A
Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxide ion concentration of this lake? A) 1 × 10-10 mol of hydroxide ions per liter of lake water B) 1 × 10-4 mol of hydroxide ions per liter of lake water C) 4.0 M with regard to hydroxide ion concentration D) 4.0 × 10-4 mol of hydroxide ions per liter of lake water
Answer: A
Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely _____. A) positively charged B) negatively charged C) without charge D) nonpolar
Answer: A
Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules because they _____. A) do not have a polar or charged region B) do not have a nonpolar region C) have hydrophobic and hydrophilic regions D) are highly reduced molecules
Answer: A
Elements found on the left side of the periodic table contain outer shells that are _____; these elements tend to form _____ in solution. A) almost empty; cations B) almost empty; anions C) almost full; cations D) almost full; anions
Answer: A
Fluorine has an atomic number of 9. Which of the following would you do to a neutral fluorine atom to complete its valence shell? A) add 1 electron B) add 2 electrons C) remove 1 electron D) Nothing. If fluorine is neutral, it has a complete valance shell.
Answer: A
How many electrons will a single atom of sulfur with no charge and no bonds have in its valence shell (see the figure above)? A) 6 B) 8 C) 16 D) 32
Answer: A
Humans can digest starch but not cellulose because _____. A) humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β- glycosidic linkages of cellulose B) starch monomers are joined by covalent bonds and cellulose monomers are joined by ionic bonds C) the monomer of starch is glucose, while the monomer of cellulose is galactose D) the monomer of starch is fructose, while the monomer of cellulose is glucose
Answer: A
Hydrophobic substances such as vegetable oil are _____. A) nonpolar substances that repel water molecules B) nonpolar substances that have an attraction for water molecules C) polar substances that repel water molecules D) polar substances that have an affinity for water
Answer: A
If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions _____. A) is 10 times higher in the cytoplasm than in the mitochondrial matrix B) is 10 times higher in the mitochondrial matrix than in the cytoplasm C) in the cytoplasm is 7/8 the concentration in the mitochondrial matrix D) in the cytoplasm is 8/7 the concentration in the mitochondrial matrix
Answer: A
Lipids _____. A) are insoluble in water B) are made from glycerol, fatty acids, and nitrogen C) contain less energy than proteins and carbohydrates D) are made by dehydration reactions
Answer: A
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers from 92-100. Therefore, which of the following can be true? A) Molybdenum atoms can have between 50 and 58 neutrons. B) Molybdenum atoms can have between 50 and 58 protons. C) Molybdenum atoms can have between 50 and 58 electrons. D) Isotopes of molybdenum have different numbers of electrons.
Answer: A
Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)? A) Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge. B) Ammonia has an overall positive charge. C) Ammonia has an overall negative charge. D) The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge.
Answer: A
Nitrogen (N) normally forms three covalent bonds with a valence of 5. However, ammonium has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of 1). What do you predict to be the charge on ammonium? A) +1 B) -1 C) +2 D) -2
Answer: A
Nucleic acids are polymers made up of which of the following monomers? A) nucleotides B) sugars C) amino acids D) nitrogenous bases
Answer: A
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+), as noted below. If the pH of blood increases, one would expect _____. A) a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3- B) an increase in the concentration of H2CO3 and a decrease in the concentration of HCO3- C) a decrease in the concentration of HCO3- and an increase in the concentration of H+ D) an increase in the concentration of HCO3- and a decrease in the concentration of OH-
Answer: A
Starch and cellulose _____. A) are polymers of glucose B) are cis-trans isomers of each other C) are used for energy storage in plants D) are structural components of the plant cell wall
Answer: A
The application of scientific knowledge for some specific purpose is known as _____. A) technology B) deductive science C) inductive science D) pure science
Answer: A
Which of these provides evidence of the common ancestry of all life? A) near universality of the genetic code B) structure of the nucleus C) structure of cilia D) structure of chloroplasts
Answer: A
The complexity and variety of organic molecules is due to _____. A) the chemical versatility of carbon atoms B) the variety of rare elements in organic molecules C) the diverse bonding patterns of nitrogen D) their interaction with water
Answer: A
The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Hydrogenated vegetable oil _____. A) is solid at room temperature B) has more "kinks" in the fatty acid chains C) has fewer trans fatty acids D) is less likely to clog arteries
Answer: A
The molecule shown in the accompanying figure is _____. A) a hexose B) a pentose C) fructose D) maltose
Answer: A
The phylogenetic tree below _____. A) depicts the three major domains of life B) includes unicellular but not multicellular life C) includes unicellular and some forms of multicellular life, but not complex animals and plants D) includes noncellular life-forms
Answer: A
Van der Waals interactions may result when _____. A) electrons are not symmetrically distributed in a molecule B) molecules held by ionic bonds react with water C) two polar covalent bonds react D) a hydrogen atom loses an electron
Answer: A
Water molecules can form hydrogen bonds with _____. A) compounds that have polar covalent bonds B) oils C) oxygen gas (O2) molecules D) chloride ions
Answer: A
What does the term insoluble fiber refer to on food packages? A) cellulose B) polypeptides C) starch D) amylopectin
Answer: A
What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-12 M? A) pH 2 B) pH 4 C) pH 10 D) pH 12
Answer: A
When nucleotides polymerize to form a nucleic acid _____. A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second C) covalent bonds form between the bases of two nucleotides D) hydrogen bonds form between the bases of two nucleotides
Answer: A
Which bond or interaction would be difficult to disrupt when compounds are put into water? A) covalent bonds between carbon atoms B) hydrogen bonds C) ionic bonds D) ionic and hydrogen bonds
Answer: A
Which functional group shown above is characteristic of alcohols? A)A B) B C) C D) D
Answer: A
Which molecule shown above can function as a base? A)A B) B C) C D) D
Answer: A
Which molecule shown above contains an amino functional group, but is NOT an amino acid? A)A B) B C) C D) D
Answer: A
Which molecule shown above has a carbonyl functional group in the form of an aldehyde? A)A B) B C) C D) D
Answer: A
Which molecules shown above contain a carbonyl group? A)Aand B B) B and C C) B, C, and D D) C and D
Answer: A
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart. B) Dehydration reactions eliminate water from membranes; hydrolysis reactions add water to membranes. C) Dehydration reactions and hydrolysis reactions assemble polymers from monomers. D) Hydrolysis reactions create polymers and dehydration reactions create monomers.
Answer: A
Which of the following correctly describes a reaction that has reached chemical equilibrium? A) The rate of the forward reaction is equal to the rate of the reverse reaction. B) All of the reactants have been converted to the products of the reaction. C) All of the products have been converted to the reactants of the reaction. D) Both the forward and the reverse reactions have stopped, with no net effect on the concentration of the reactants and the products.
Answer: A
Which of the following correctly describes all chemical equilibrium? A) Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products. B) Concentrations of products are higher than the concentrations of the reactants. C) There are equal concentrations of products and reactants while forward and reverse reactions continue. D) There are equal concentrations of reactants and products, and the reactions have stopped
Answer: A
Which of the following is NOT a polymer? A) glucose B) starch C) cellulose D) DNA
Answer: A
Which of the following is the best explanation for why vegetable oil is a liquid at room temperature while animal fats are solid? A) Vegetable oil has more double bonds than animal fats. B) Vegetable oil has fewer double bonds than animal fats. C) Animal fats have no amphipathic character. D) Vegetable oil has longer fatty-acid tails than animal fats have
Answer: A
Which of the following molecules is polar? C3H7OH C2H5COOH A) C3H7OH and C2H5COOH are both polar molecules. B) Neither C2H5COOH or C3H7OH is polar. C) C2H5COOH is polar, but C3H7OH is not polar. D) C3H7OH is not polar, but C3H7OH is polar.
Answer: A
Which of the following solutions would require the addition of the greatest amount of base to bring the solution to neutral pH? A) gastric juice at pH 2 B) vinegar at pH 3 C) black coffee at pH 5 D) household bleach at pH 12
Answer: A
Which of the following statements correctly describes cis-trans isomers? A) They have variations in arrangement around a double bond. B) They have an asymmetric carbon that makes them mirror images. C) They have the same chemical properties. D) They have different molecular formulas.
Answer: A
Which of these classes of biological molecules does NOT include polymers? A) lipids B) carbohydrates C) proteins D) nucleic acids
Answer: A
Which of these is an example of inductive reasoning? A) Hundreds of individuals of a species have been observed and all are photosynthetic; therefore, the species is photosynthetic. B) These organisms live in sunny regions. Therefore, they are using photosynthesis. C) If protists are all single-celled, then they are incapable of aggregating. D) If two species are members of the same genus, they are more alike than each of them could be to a different genus.
Answer: A
Which one of the atoms shown would be most likely to form a cation with a charge of +1? *the answers are diagrams showing the amount of elections.
Answer: A
Which one of the following is NOT a component of each monomer used to make proteins? A) a phosphorus atom, P B) an amino functional group, NH2 C) a side chain, R D) a carboxyl group, COOH
Answer: A
Which polysaccharide is an important component in the structure of many animals and fungi? A) chitin B) cellulose C) amylopectin D) amylose
Answer: A
Why is a scientific topic best discussed by people of varying points of view, from different subdisciplines, and representing diverse cultures? A) Robust and critical discussion between diverse groups improves scientific thinking. B) Scientists can coordinate with others to conduct experiments in similar ways. C) This is a way of ensuring that everyone gets the same results. D) People need to exchange their ideas with other disciplines and cultures because everyone has a right to an opinion in science.
Answer: A
You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure
Answer: A
You find yourself standing next to a beautiful rose bush. Which of the following do you and the rose have in common? A) You both are multicellular. B) You both lack a membrane-bound nucleus. C) You are both prokaryotic. D) You and the rose have nothing in common.
Answer: A
You need to write down information about a molecule, but need to indicate only the type and number of atoms it contains. Which representation would work best? A) molecular formula B) structural formula C) ball-and-stick model D) space-filling model
Answer: A
10) Water has many exceptional and useful properties. Which is the rarest property among compounds? A) Water is a solvent. B) Solid water is less dense than liquid water. C) Water has a high heat capacity. D) Water has surface tension.
Answer: B
A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound _____. A) lacks an asymmetric carbon and is probably a fat or lipid B) should dissolve in water C) should dissolve in a nonpolar solvent D) will not form hydrogen bonds with water
Answer: B
A controlled experiment _____. A) is repeated many times to ensure that the results are accurate B) includes at least two groups, one of which does not receive the experimental treatment C) includes at least two groups, one differing from the other by two or more variables D) includes one group for which the scientist controls all variables
Answer: B
A glycosidic linkage is analogous to which of the following in proteins? A) an amino group B) a peptide bond C) a disulfide bond D) a β-pleated sheet
Answer: B
A localized group of organisms that belong to the same species is called a _____. A) community B) population C) ecosystem D) family
Answer: B
A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a _____. A) slightly damp surface B) surface of hydrocarbons C) surface of mostly carbon-oxygen bonds D) surface of mostly carbon-nitrogen bonds
Answer: B
All of the following contain amino acids EXCEPT _____. A) hemoglobin B) cholesterol C) enzymes D) insulin
Answer: B
Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results?
Answer: B
Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms, but with one or more double bonds, will _____. A) be more flexible in structure B) be more constrained in structure C) be more polar D) have more hydrogen atoms
Answer: B
Consider the following reaction at equilibrium...What would be the effect of adding additional H2CO3? A) It would drive the equilibrium dynamics to the right. B) It would drive the equilibrium dynamics to the left. C) Nothing would happen, because the reactants and products are in equilibrium. D) The amounts of CO2 and H2O would decrease.
Answer: B
Differences among organisms are caused by differences in the _____. A) elemental composition from organism to organism B) types and relative amounts of organic molecules synthesized by each organism C) sizes of the organic molecules in each organism D) types of inorganic compounds present in each organism
Answer: B
How does a scientific theory differ from a scientific hypothesis? A) Theories are proposed to test scientific hypotheses. B) Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues. C) Hypotheses are usually an explanation for a more general phenomenon; theories typically address more specific issues. D) Confirmed theories become scientific laws; hypotheses become theories.
Answer: B
How many electron pairs are shared between carbon atoms in a molecule that has the formula C2H4? A) 1 B) 2 C) 3 D) 4
Answer: B
How many electrons are involved in a single covalent bond? A) one B) two C) three D) four
Answer: B
How many grams of the compound in the figure above are required to make 1 liter of a 0.5 M solution? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) A) 29 B) 30 C) 60 D) 150
Answer: B
Identical heat lamps are arranged to shine on two identical containers, one containing water and one methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?
Answer: B
If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? A) DNA B) RNA C) both DNA and RNA D) proteins
Answer: B
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? A) 10 B) 40 C) 80 D) It is impossible to tell from the information given.
Answer: B
If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence _____. A) 5'TAACGT3' B) 5'TGCAAT3' C) 3'UAACGU5' D) 5'UGCAAU3'
Answer: B
Which two functional groups are always found in amino acids? A) carbonyl and amino groups B) carboxyl and amino groups C) amino and sulfhydryl groups D) hydroxyl and carboxyl groups
Answer: B
In living systems molecules involved in hydrogen bonding almost always contain either oxygen or nitrogen or both. How do you explain this phenomenon? A) Oxygen and nitrogen are elements found in both nucleic acids and proteins. B) Oxygen and nitrogen are elements with very high attractions for their electrons. C) Oxygen and nitrogen are elements found in fats and carbohydrates. D) Oxygen and nitrogen were both components of gases that made up the early atmosphere on Earth.
Answer: B
Magnesium has an atomic number of 12. What is the most stable charge for a magnesium ion? A) a +1 charge B) a +2 charge C) a -1 charge D) a -2 charge
Answer: B
One of the primary functions of RNA molecules is to_____ A) transmit genetic information to offspring B) function in the synthesis of proteins C) make a copy of itself, thus ensuring genetic continuity D) act as a pattern or blueprint to form DNA
Answer: B
Refer to the figure above (first three rows of the periodic table). What element has properties most similar to carbon? A) boron B) silicon C) nitrogen D) phosphorus
Answer: B
Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that _____. A) have identical chemical formulas but differ in the branching of their carbon skeletons B) are mirror images of each other C) differ in the location of their double bonds D) differ in the arrangement of atoms around their double bonds
Answer: B
Saturated fatty acids _____. A) have double bonds between carbon atoms of the fatty acids B) are the principal molecules in lard and butter C) are usually liquid at room temperature D) are usually produced by plants
Answer: B
Stanley Miller's 1953 experiments supported the hypothesis that _____. A) life on Earth arose from simple inorganic molecules B) organic molecules can be synthesized abiotically under conditions that may have existed on early Earth C) life on Earth arose from simple organic molecules, with energy from lightning and volcanoes D) the conditions on early Earth were conducive to the origin of life
Answer: B
Steroids are considered to be lipids because they _____. A) are essential components of cell membranes B) are not soluble in water C) are made of fatty acids D) contribute to atherosclerosis
Answer: B
Thalidomide and L-dopa, shown below, are examples of pharmaceutical drugs that occur as enantiomers, or molecules that _____. A) have identical three-dimensional shapes B) are mirror images of one another C) are mirror images of one another and have the same biological activity D) are cis-trans isomers
Answer: B
The R-group, or side chain, of the amino acid serine is -CH2-OH. The R-group, or side chain, of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution? A) Serine would be in the interior, and leucine would be on the exterior of the globular protein. B) Leucine would be in the interior, and serine would be on the exterior of the globular protein. C) Serine and leucine would both be in the interior of the globular protein. D) Serine and leucine would both be on the exterior of the globular protein.
Answer: B
The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride? A) MgCl B) MgCl2 C) Mg2Cl D) MgCl3
Answer: B
The atomic number of nitrogen is 7. Nitrogen-15 has a greater mass number than nitrogen-14 because the atomic nucleus of nitrogen-15 contains _____. A) 7 neutrons B) 8 neutrons C) 8 protons D) 15 protons
Answer: B
The chemical reaction illustrated in the accompanying figure _____. A) is a hydrolysis reaction B) results in a peptide bond C) joins two fatty acids together D) links two polymers to form a monomer
Answer: B
The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why? A) They are not at the same exact latitude. B) The ocean near Portland moderates the temperature. C) Fresh water is more likely to freeze than salt water. D) Minneapolis is much windier, due to its location in the middle of North America.
Answer: B
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? A) C18H36O18 B) C18H32O16 C) C6H10O5 D) C18H30O15
Answer: B
The molecule shown the accompanying figure is a _____. A) fatty acid B) steroid C) protein D) phospholipid
Answer: B
The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called? A) a covalent bond B) a hydrogen bond C) an ionic bond D) a van der Waals interaction
Answer: B
The partial negative charge in a molecule of water occurs because _____. A) the oxygen atom donates an electron to each of the hydrogen atoms B) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus C) the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms D) one of the hydrogen atoms donates an electron to the oxygen atom
Answer: B
The tertiary structure of a protein is the _____. A) order in which amino acids are joined in a polypeptide chain B) unique three-dimensional shape of the fully folded polypeptide C) organization of a polypeptide chain into an α-helix or β-pleated sheet D) overall protein structure resulting from the aggregation of two or more polypeptide subunits
Answer: B
The two molecules shown in the figure below are best described as _____. A) enantiomers B) structural isomers C) cis-trans isomers D) chain length isomers
Answer: B
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) calcium B) iodine C) sodium D) phosphorus
Answer: B
Which of the following includes all of the pyrimidines found in RNA and DNA? A) cytosine and uracil B) cytosine and thymine C) cytosine, uracil, and thymine D) cytosine, uracil, and guanine
Answer: C
What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration? A) the presence or absence of bonds with oxygen atoms B) the presence or absence of double bonds between the carbon atom and other atoms C) the polarity of the covalent bonds between carbon and other atoms D) the solvent in which the organic molecule is dissolved
Answer: B
What is the difference between covalent bonds and ionic bonds? A) Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. B) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. C) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms. D) Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms.
Answer: B
What is the maximum number of covalent bonds that an oxygen atom with atomic number 8 can make with hydrogen? A) 1 B) 2 C) 4 D) 6
Answer: B
What is the term used for a protein molecule that assists in the proper folding of other proteins? A) tertiary protein B) chaperonin C) renaturing protein D) denaturing protein
Answer: B
What results from an unequal sharing of electrons between atoms? A) a nonpolar covalent bond B) a polar covalent bond C) an ionic bond D) a hydrophobic interaction
Answer: B
When a person gets dehydrated while exercising on a hot day, their pituitary gland releases ADH, a hormone that signals the kidneys to retain more water. This is an example of A) Positive feedback regulation B) Negative feedback regulation C) Chemical cycling D) Emergent properties
Answer: B
When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)? A) 1 liter of 0.5 M NaCl B) 1 liter of 1.0 M NaCl C) 1 liter of 1.0 M glucose D) 1 liter of 1.0 M NaCl and 1 liter of 1.0 M glucose will contain equal numbers of solute particles.
Answer: B
Which branch of biology is concerned with the naming and classifying of organisms? A) informatics B) taxonomy C) genomics D) evolution
Answer: B
Which level of protein structure do the α-helix and the β-pleated sheet represent? A) primary B) secondary C) tertiary D) quaternary
Answer: B
Which molecule has both hydrophilic and hydrophobic properties and is found in plasma membranes? A) 1 B) 5 C) 12 D) 14
Answer: B
Which molecule shown above can form a cross linkage? A)A B) B C) C D) D
Answer: B
Which molecule shown above has a carbonyl functional group in the form of a ketone? A)A B) B C) C D) D
Answer: B
Which molecule shown above is a thiol? A)A B) B C) C D) D
Answer: B
Which of the following best describes a model organism? A) It is often pictured in textbooks and easy for students to imagine. B) It is well studied, it is easy to grow, and results are widely applicable. C) It is small, inexpensive to raise, and lives a long time. D) It has been chosen for study by early biologists.
Answer: B
Which of the following best describes the relationship between the atoms described below? A) They are isomers. B) They are isotopes. C) They contain 1 and 3 protons, respectively. D) They each contain only 1 neutron.
Answer: B
Which of the following can be attributed to water's high specific heat? A) Oil and water do not mix well. B) A lake heats up more slowly than the air around it. C) Ice floats on water. D) Sugar dissolves in hot tea faster than in iced tea.
Answer: B
Which of the following effects can occur because of the high surface tension of water? A) Lakes cannot freeze solid in winter, despite low temperatures. B) A raft spider can walk across the surface of a small pond. C) Organisms can resist temperature changes, although they give off heat due to chemical reactions. D) Sweat can evaporate from the skin, helping to keep people from overheating.
Answer: B
Which of the following is the best description of a control for an experiment? A) The control group is kept in an unchanging environment. B) The control group is matched with the experimental group except for one experimental variable. C) The control group is exposed to only one variable rather than several. D) Only the experimental group is tested or measured.
Answer: B
Which of the following statements about the 5' end of a polynucleotide strand of RNA is correct?
Answer: B
Which of the following statements is FALSE? Saturated fats _____. A) are more common in animals than in plants B) have many double bonds in the carbon chains of their fatty acids C) usually solidify at room temperature D) contain more hydrogen than unsaturated fats that consist of the same number of carbon ato
Answer: B
Which of the following takes place as an ice cube cools a drink? A) Molecular collisions in the drink increase. B) Kinetic energy in the liquid water decreases. C) A calorie of heat energy is transferred from the ice to the water of the drink. D) The specific heat of the water in the drink decreases.
Answer: B
Which of the groups above is a carboxyl functional group? A)A B) B C) C D) D
Answer: B
Which of the groups above is an acidic functional group that can dissociate and release H+ into a solution? A)A B) B C) C D) D
Answer: B
Which of the pairs of molecular structures shown below do NOT depict enantiomers (enantiomeric forms) of the same molecule?
Answer: B
Which of the structures illustrated above is an impossible covalently bonded molecule? A)A B) B C) C D) D
Answer: B
Why are hydrocarbons insoluble in water? A) The majority of their bonds are polar covalent carbon-to-hydrogen linkages. B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. C) They exhibit considerable molecular complexity and diversity. D) They are less dense than water.
Answer: B
37) What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms? A) 2 B) 4 C) 6 D) 8
Answer: C
A carbon atom is most likely to form what kind of bond(s) with other atoms? A) ionic B) hydrogen C) covalent D) ionic bonds, covalent bonds, and hydrogen bond
Answer: C
A covalent chemical bond is one in which _____. A) electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged B) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms C) outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals D) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom
Answer: C
A dietary Calorie equals 1 kilocalorie. Which of the following statements correctly defines 1 kilocalorie? One kilocalorie equals _____. A) 1000 calories, or the amount of heat required to raise the temperature of 1 g of water by 1°C B) 10,000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°F C) 1000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°C D) 1000 calories, or the amount of heat required to raise the temperature of 100 g of water by 100°C
Answer: C
A friend of yours calls to say that his car would not start this morning. He asks for your help. You say that you think the battery must be dead. If so, then jump-starting the car from a good battery will solve the problem. In doing so, you are _____. A) testing a theory for why the car will not start B) making observations to inspire a theory for why the car will not start C) stating a hypothesis and using that hypothesis to make a testable prediction D) comparing multiple hypotheses for why the car will not start
Answer: C
A hydrocarbon skeleton is covalently bonded to an amino group at one end and a carboxyl group at the other end. When placed in water this molecule would function _____. A) only as an acid because of the carboxyl group B) only as a base because of the amino group C) as an acid and a base D) as neither an acid nor a base
Answer: C
A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7? A) 5 times B) 10 times C) 100 times D) 1000 times
Answer: C
Agrobacterium infects plants and causes them to form tumors. You determine that tumor formation requires a large amount of the plant's energy for tissue formation. How might this change the number of offspring a plant produces, and what is the most likely explanation for this change? A) The number of offspring should increase, because in general, illness increases the reproductive output of organisms. B) The number of offspring should increase, because the bacteria will provide energy for the plant. C) The number of offspring should decrease, because the plant will divert energy from reproduction to tumor formation. D) There should be no effect of infection on offspring production because energy for reproduction is independent of infection.
Answer: C
Amino acids are acids because they always possess which functional group? A) amino B) carbonyl C) carboxyl D) phosphate
Answer: C
Based on electron configuration, which of the elements in the figure above would exhibit a chemical behavior most like that of oxygen? A) carbon B) nitrogen C) sulfur D) phosphorus
Answer: C
Bonds between two atoms that are equally electronegative are _____. A) hydrogen bonds B) polar covalent bonds C) nonpolar covalent bonds D) ionic bonds
Answer: C
Carbon-12 is the most common isotope of carbon and has a mass number of 12. However, the average atomic mass of carbon found on a periodic table is slightly more than 12 daltons. Why? A) The atomic mass does not include the mass of electrons. B) Some carbon atoms in nature have an extra proton. C) Some carbon atoms in nature have more neutrons. D) Some carbon atoms in nature have a different valence electron distribution.
Answer: C
Charles Darwin proposed a mechanism for descent with modification that stated that organisms of a particular species are adapted to their environment when they possess _____. A) non-heritable traits that enhance their survival in the local environment B) non-heritable traits that enhance their survival and reproductive success in the local environment C) heritable traits that enhance their survival and reproductive success in the local environment D) heritable traits that decrease their survival and reproductive success in the local environment
Answer: C
Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should _____. A) test whether other traits in these males are also adaptive B) look for evidence of hair in ancestors of tamarins C) determine if hair length is heritable D) test whether males with shaved heads are still able to mate
Answer: C
Darwin's finches, collected from the Galápagos Islands, illustrate which of the following? A) mutation frequency B) ancestors from different regions C) adaptive radiation D) vestigial anatomical structures E) the accuracy of the fossil record
Answer: C
How do phospholipids interact with water molecules? A) The polar heads avoid water; the nonpolar tails attract water (because water is polar and opposites attract) B) Phospholipids do not interact with water because water is polar and lipids are nonpolar. C) The polar heads interact with water; the nonpolar tails do not. D) Phospholipids dissolve in water.
Answer: C
How many electron pairs does carbon share to complete its valence shell? A) 2 B) 3 C) 4 D) 8
Answer: C
How many molecules of water are used to completely hydrolyze a polymer that is 11 monomers long? A) 12 B) 11 C) 10 D) 9
Answer: C
How many neutrons are present in the nucleus of a phosphorus-32 (32P) atom (see the figure above)? A) 15 B) 16 C) 17 D) 32
Answer: C
Which of the following illustrations is NOT a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.
Answer: C
If the pH of a solution is decreased from 9 to 8, it means that the concentration of _____. A) H+ has decreased to one-tenth (1/10) what it was at pH 9 B) H+ has doubled compared to what it was at pH 9 C) H+ has increased tenfold (10X) compared to what it was at pH 9 D) OH- has increased tenfold (10X) compared to what it was at pH 9
Answer: C
If you change the number of neutrons in an atom, you create _____. A) a cation B) an anion C) an isotope D) a different element
Answer: C
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by _____. A) hydrogen bonds B) nonpolar covalent bonds C) polar covalent bonds D) ionic bonds
Answer: C
In presenting data that result from an experiment, a group of students show that most of their measurements fall on a straight diagonal line on their graph. However, two of their data points are "outliers" and fall far to one side of the expected relationship. What should they do? A) Do not show these points because clearly something went wrong in the experiment. B) Average several trials, rule out the improbable results, and do not show them in the final work. C) Show all results obtained and then try to explore the reason(s) for these outliers. D) Change the details of the experiment until they can obtain the expected results.
Answer: C
In the process of science, which of these is tested? A) a result B) an observation C) a hypothesis D) a control group
Answer: C
In what way are elements in the same column of the periodic table the same? They have the same number of _____. A) protons B) electrons when neutral C) electrons in their valence shells when neutral D) electron shells when neutral
Answer: C
Increased atmospheric CO2 concentrations might have what effect on seawater? A) Seawater will become more alkaline, and carbonate concentrations will decrease. B) There will be no change in the pH of seawater, because carbonate will turn to bicarbonate. C) Seawater will become more acidic, and carbonate concentrations will decrease. D) Seawater will become more acidic, and carbonate concentrations will increase.
Answer: C
Knowing the atomic mass of an element allows inferences about which of the following? A) the number of electrons in the element B) the number of protons in the element C) the number of protons plus neutrons in the element D) the number of protons plus electrons in the element
Answer: C
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 hexose B) as a monosaccharide C) as a disaccharide D) as a polysaccharide
Answer: C
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 liter of a solution of pH 6? A) 4 times more B) 40,000 times more C) 10,000 times more D) 100,000 times more
Answer: C
One mole of the compound above would weigh how many grams? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) A) 29 B) 30 C) 60 D) 150
Answer: C
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+), as noted below. If the pH of blood drops, one would expect _____. A) a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3- B) the concentration of bicarbonate ions (HCO3-) to increase C) the HCO3- to act as a base and remove excess H+ by the formation of H2CO3 D) the HCO3- to act as an acid and remove excess H+ by the formation of H2CO3
Answer: C
Phospholipids and triglycerides both _____. A) contain serine or some other organic compound B) have three fatty acids C) have a glycerol backbone D) have a phosphate
Answer: C
Proteorhodopsin consists of a single polypeptide chain. What is the highest level of structure found in this protein? A) primary B) secondary C) tertiary D) quaternary
Answer: C
Recall the caterpillar experiment in which caterpillars born in the spring looked like flowers, and caterpillars born in the summer looked like twigs. What is the most likely selective advantage for this difference in body shape? A) Looking like their food sources allows the caterpillars to move through their environment more efficiently B) Development into the adult moth form is faster for caterpillars shaped like twigs than like flowers. C) Looking like their food source lets the caterpillars blend into their surroundings, reducing predation. D) Looking like their food source will increase the caterpillars' feeding efficiency; this would increase their growth rate and survival rate.
Answer: C
Refer to the accompanying figure. In every case, caterpillars that feed on oak flowers look like oak flowers. In every case, caterpillars that were raised on oak leaves looked like twigs. These results support which of the following hypotheses? A) The longer day lengths of summer trigger the development of twig-like caterpillars. B) Differences in air pressure, due to elevation, trigger the development of different types of caterpillars. C) Differences in diet trigger the development of different types of caterpillars. D) The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like caterpillars.
Answer: C
Refer to the paragraph on Redi's experiments. What hypothesis was being tested in the initial experiment with open versus sealed jars? A) Spontaneous generation is more likely during the long days of summer. B) The type of meat used affects the likelihood of spontaneous generation. C) Maggots do not arise spontaneously, but from eggs laid by adult flies. D) Spontaneous generation can occur only if meat is exposed to air.
Answer: C
Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol _____. A) are structural isomers but have the same molecular formula B) are cis-trans isomers but have the same molecular formula C) have different functional groups attached to the same carbon skeleton D) are enantiomers of the same organic molecule
Answer: C
The element present in all organic molecules is _____. A) hydrogen B) oxygen C) carbon D) nitrogen
Answer: C
The figure above shows the structures of glucose and fructose. These two molecules differ in the _____. A) number of carbon, hydrogen, and oxygen atoms B) types of carbon, hydrogen, and oxygen atoms C) arrangement of carbon, hydrogen, and oxygen atoms D) number of oxygen atoms joined to carbon atoms by double covalent bonds
Answer: C
The following experiment is used for the corresponding question(s). A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers. But caterpillars that hatch in summer feed on oak leaves and look like oak twigs. How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below. In each of the four environments, one of the caterpillars was fed oak flowers, the other oak leaves. Thus, there were a total of eight treatment groups (4 environments × 2 diets). 19) Refer to the accompanying figure. Which one of the following is NOT a plausible hypothesis to explain the differences in caterpillar appearance observed in this population? A) The longer day lengths of summer trigger the development of twig-like caterpillars. B) The cooler temperatures of spring trigger the development of flowerlike caterpillars. C) Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars. D) Differences in diet trigger the development of different types of caterpillars.
Answer: C
The loss of water from a plant by transpiration cools the leaf. Movement of water in transpiration requires both adhesion to the conducting walls and wood fibers of the plant and cohesion of the molecules to each other. A scientist wanted to increase the rate of transpiration of a crop species to extend its range into warmer climates. The scientist substituted a nonpolar solution with an atomic mass similar to that of water for hydrating the plants. What do you expect the scientist's data will indicate from this experiment? A) The rate of transpiration will be the same for both water and the nonpolar substance. B) The rate of transpiration will be slightly lower with the nonpolar substance as the plant will not have evolved with the nonpolar compound. C) Transpiration rates will fall to zero as nonpolar compounds do not have the properties necessary for adhesion and cohesion. D) Transpiration rates will increase as nonpolar compounds undergo adhesion and cohesion with wood fibers more readily than water.
Answer: C
The molecule illustrated in the accompanying figure _____. A) is a saturated fatty acid. B) stores genetic information. C) will be liquid at room temperature. D) is a carbohydrate.
Answer: C
To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology? A) evolution B) emergent properties C) reductionism D) feedback regulation
Answer: C
Water molecules are attracted to one another by _____. A) nonpolar covalent bonds B) ionic bonds C) hydrogen bonds D) hydrophobic interactions
Answer: C
What causes the shape of the molecule shown above? A) the shape of the 2 p orbitals in the carbon atom B) the shape of the 1 s orbital in the carbon atom C) the shape of the sp3 hybrid orbitals of the electrons shared between the carbon and hydrogen atoms D) hydrogen bonding configurations between the carbon and hydrogen atoms
Answer: C
What component of amino acid structure varies among different amino acids? A) the long carbon-hydrogen tails of the molecule B) the presence of a central C atom C) the components of the R-group D) the glycerol molecule that forms the backbone of the amino acid
Answer: C
What is the atomic number of the cation formed in the reaction illustrated above? A) 8 B) 10 C) 11 D) 16
Answer: C
What is the difference between an aldose sugar and a ketose sugar? A) the number of carbons B) the position of the hydroxyl groups C) the position of the carbonyl group D) One is a ring form, the other is a linear chain/
Answer: C
What is the hydrogen ion (H+) concentration of a solution of pH 8? A) 8 M B) 8 x 10-6 M C) 10-8 M D) 10-6 M
Answer: C
When are atoms most stable? A) when they have the fewest possible valence electrons B) when they have the maximum number of unpaired electrons C) when all of the electron orbitals in the valence shell are filled D) when all electrons are paired
Answer: C
When the atoms involved in a covalent bond have the same electronegativity, what type of bond results? A) an ionic bond B) a hydrogen bond C) a nonpolar covalent bond D) a polar covalent bond
Answer: C
Which chemical group can act as an acid? A) amino B) carbonyl C) carboxyl D) methyl
Answer: C
Which molecule shown above can increase the concentration of hydrogen ions in a solution and is, therefore, an organic acid? A)A B) B C) C D) D
Answer: C
Which molecule shown above contains a carboxyl group? A)A B) B C) C D) D
Answer: C
Which molecule(s) shown above is (are) ionized in a cell? A)A B) B and D C) C and D D) D
Answer: C
Which of the following are qualities of any good scientific hypothesis? I. It is testable. II. It is falsifiable. III. It produces quantitative data. IV. It produces results that can be replicated. A) I only B) III only C) I and II D) III and IV
Answer: C
Which of the following best describes what occurred after the publication of Charles Darwin's On the Origin of Species? A) The publisher was pressured to cease distribution. B) The book was banned from schools. C) The book was widely discussed and disseminated. D) The book was discredited by most scientists.
Answer: C
Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base and a phosphate group B) a nitrogenous base and a sugar C) a nitrogenous base, a phosphate group, and a sugar D) a sugar and a purine or pyrimidine
Answer: C
Which of the following is a property of liquid water? Liquid water _____. A) is less dense than ice B) has a specific heat that is lower than that for most other substances C) has a heat of vaporization that is higher than that for most other substances D) is nonpolar
Answer: C
Which of the following is the best description of an atom's physical structure? A) An atom is a solid mass of material. B) The particles that form an atom are equidistant from each other. C) Atoms are little bubbles of space with mass concentrated at the center of the bubble. D) Atoms are little bubbles of space with mass concentrated on the outside surface of the bubble.
Answer: C
Which of the following is true for this reaction? A) The reaction is nonreversible. B) Hydrogen and nitrogen are the reactants of the reverse reaction. C) Ammonia is being formed and decomposed simultaneously. D) Only the forward or reverse reactions can occur at one time.
Answer: C
Which of the following statements best summarizes the differences between DNA and RNA? A) DNA encodes hereditary information, whereas RNA does not. B) The bases in DNA contain sugars, whereas the bases in RNA do not contain sugar. C) DNA nucleotides contain a different sugar than RNA nucleotides. D) DNA contains the base uracil, whereas RNA contains the base thymine
Answer: C
Which of the following statements is FALSE regarding the complexity of biological systems? A) An understanding of the interactions between different components within a living system is a key goal of a systems biology approach to understanding biological complexity. B) Knowing the function of a component of a living system can provide insight into its structure and organization. C) Understanding the chemical structure of DNA reveals how it directs the functioning of a living cell. D) An ecosystem displays complex properties not present in the individual communities within it.
Answer: C
Which of the following statements is FALSE? A) Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter. B) Some naturally occurring elements are toxic to organisms. C) All life requires the same essential elements. D) Iron is needed by all humans.
Answer: C
Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? A) animal B) plant C) archaean D) fungi
Answer: C
Which of the functional groups below acts most like an acid in water? A) amino B) carbonyl C) carboxyl D) hydroxyl
Answer: C
Which of the groups above is a basic functional group that can accept H+ and become positively charged? A)A B) B C) C D) D
Answer: C
Which of the pairs of molecular structures shown below depict enantiomers (enantiomeric forms) of the same molecule?
Answer: C
Which type of bond must be broken for water to vaporize? A) ionic bonds B) polar covalent bonds C) hydrogen bonds D) both polar covalent bonds and hydrogen bonds
Answer: C
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) Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water. D) The crystalline lattice of ice causes it to be denser than liquid water.
Answer: C
You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding? A) Cysteine residues are required for the formation of α-helices and β-pleated sheets. B) It will be important to include cysteine in the diet of the mice. C) Cysteine residues are involved in disulfide bridges that help form tertiary structure. D) Cysteine causes bends, or angles, to occur in the tertiary structure of proteins.
Answer: C
You have two beakers. One contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen. A) Equal amounts of NaCl crystals will dissolve in both water and methanol. B) NaCl crystals will not dissolve in either water or methanol. C) NaCl crystals will dissolve readily in water but will not dissolve in methanol. D) NaCl crystals will dissolve readily in methanol but will not dissolve in water.
Answer: C
n comparison to eukaryotes, prokaryotes _____. A) are more structurally complex B) are larger C) are smaller D) do not have membranes
Answer: C
) Oxygen has an atomic number of 8 and most commonly, a mass number of 16. Thus, what is the atomic mass of an oxygen atom? A) approximately 8 grams B) approximately 8 daltons C) approximately 16 grams D) approximately 16 daltons
Answer: D
A beaker contains 100 milliliters (mL) of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the result of this mixing? A) The concentration of Na+ ions will rise. B) The pH of the beaker's contents will increase. C) The pH of the beaker's contents will be neutral. D) The pH of the beaker's contents will decrease.
Answer: D
A molecule with the chemical formula C6H12O6 is probably a _____. A) fatty acid B) polysaccharide C) nucleic acid D) monosaccharide
Answer: D
A solution contains 0.0000001 (10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution? A) acidic: H+ acceptor B) basic: H+ acceptor C) acidic: H+ donor D) neutral
Answer: D
Rank, from low to high, the pH of blood, stomach acid, and urine. A) blood, urine, and stomach acid B) stomach acid, blood, and urine C) urine, blood, stomach acid D) stomach acid, urine, blood
Answer: D
About twenty-five of the ninety-two natural elements are known to be essential to life. Which four of these twenty-five elements make up approximately 96 percent of living matter? A) carbon, sodium, hydrogen, nitrogen B) carbon, oxygen, phosphorus, hydrogen C) oxygen, hydrogen, calcium, nitrogen D) carbon, hydrogen, nitrogen, oxygen
Answer: D
Agrobacterium infects plants and causes them to form tumors. You are asked to determine how long a plant must be exposed to these bacteria to become infected. Which of the following experiments will provide the best data to address that question? A) Determine the survival rate of Agrobacterium when exposed to different concentrations of an antibiotic. B) Measure the number of tumors formed on a plant when exposed to various concentrations of Agrobacterium. C) Measure the concentration of Agrobacterium in different soil environments where the plants grow. D) Measure the number of tumors formed on plants, which are exposed to Agrobacterium for different lengths of time.
Answer: D
Can the atomic mass of an element vary? A) No, it is fixed. If it changes at all then you have formed a different element. B) Yes. Adding or losing electrons will substantially change the atomic mass. C) Yes. Adding or losing protons will change the atomic mass without forming a different element. D) Yes. Adding or losing neutrons will change the atomic mass without forming a different element.
Answer: D
Cells are _____. A) only found in pairs, because single cells cannot exist independently B) limited in size to 200 and 500 micrometers in diameter C) characteristic of eukaryotic but not prokaryotic organisms D) characteristic of prokaryotic and eukaryotic organisms
Answer: D
Changing a single amino acid in a protein consisting of 325 amino acids would _____. A) alter the primary structure of the protein but not its tertiary structure or function B) cause the tertiary structure of the protein to unfold C) always alter the biological activity or function of the protein D) always alter the primary structure of the protein, sometimes alter the tertiary structure of the protein, and sometimes affect its biological activity
Answer: D
Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that _____. A) solution Y has no free hydrogen ions (H+) B) the concentration of hydrogen ions in solution Y is 1000 times as great as the concentration of hydrogen ions in solution X C) the concentration of hydrogen ions in solution X is 3 times as great as the concentration of hydrogen ions in solution Y D) the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y
Answer: D
From its atomic number of 15, it is possible to predict that the phosphorus atom has _____. A) 5 neutrons, 5 protons, and 5 electrons B) 15 neutrons and 15 protons C) 8 electrons in its outermost electron shell D) 15 protons and 15 electrons
Answer: D
How many electrons are involved in a double covalent bond? A) one B) two C) three D) four
Answer: D
How would acidification of seawater affect marine organisms? Acidification of seawater would _____. A) increase dissolved carbonate concentrations and promote faster growth of corals and shell- building animals B) decrease dissolved carbonate concentrations and promote faster growth of corals and shell- building animals C) increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals D) decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals
Answer: D
If an atom has a charge of +1, which of the following must be true? A) It has two more protons than neutrons. B) It has the same number of protons as electrons. C) It has one more electron than it does protons. D) It has one more proton than it does electrons.
Answer: D
In the diagram below, "A" is _____ ; "B" is _____. A) the most recent species to evolve on Earth; an ancestor of group "A" B) the most recent species to evolve on Earth; the last common ancestor of Archaea and Eukarya C) the common ancestor of all life; the common ancestor of Bacteria and Archaea D) the common ancestor of all life; the last common ancestor of Archaea and Eukarya
Answer: D
In which of the structures illustrated above are the atoms bonded by ionic bonds? A)A B) B C) C D) none of the structures
Answer: D
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) Alzheimer's only B) Parkinson's only C) diabetes mellitus only D) Alzheimer's and Parkinson's only
Answer: D
Normal hemoglobin is a tetramer, consisting of two molecules of β hemoglobin and two molecules of α hemoglobin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits _____. A) only altered primary structure B) only altered tertiary structure C) only altered quaternary structure D) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered
Answer: D
One idea to mitigate the effects of burning fossil fuels on atmospheric CO2 concentrations is to pipe liquid CO2 into the ocean at depths of 2500 feet or greater. At the high pressures at such depths, CO2 is heavier than water. What potential effects might result from implementing such a scheme? A) increased carbonate concentrations in the deep waters B) increased growth of corals from a change in the carbonate-bicarbonate equilibrium C) no effect because carbon dioxide is not soluble in water D) increased acidity and decreased carbonate concentrations in the deep waters
Answer: D
One mole (mol) of glucose (molecular mass = 180 daltons) is _____. A) 180 × 1023 molecules of glucose B) 1 kilogram of glucose dissolved in 1 liter of solution C) 180 kilograms of glucose D) 180 grams of glucose
Answer: D
Organic molecules with only hydrogens and five carbon atoms cannot _____. A) have a branching carbon skeleton B) have different combinations of double bonds between carbon atoms C) have different positions of double bonds between carbon atoms D) form enantiomers
Answer: D
Prokaryotes are classified as belonging to two different domains. What are the domains? A) Bacteria and Eukarya B) Archaea and Monera C) Bacteria and Protista D) Bacteria and Archaea
Answer: D
Refer to the accompanying figure. Recall that eggs from the same female were exposed to each of the eight treatments used. This aspect of the experimental design tested which of the following hypotheses? A) The longer day lengths of summer trigger the development of twig-like caterpillars. B) Differences in air pressure, due to elevation, trigger the development of different types of caterpillars. C) Differences in diet trigger the development of different types of caterpillars. D) The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like caterpillars.
Answer: D
Refer to the paragraph on Redi's experiments. In both experiments, flies appeared in all of the open jars and only in the open jars. Which one of the following statements is correct? A) The experiment was inconclusive because Redi used only one kind of meat. B) The experiment was inconclusive because it did not run long enough. C) The experiment supports the hypothesis that spontaneous generation occurs in rotting meat. D) The experiment supports the hypothesis that maggots arise only from eggs laid by adult flies.
Answer: D
Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H2S will _____. A) have greater cohesion to other molecules of H2S B) have a greater tendency to form hydrogen bonds with each other C) have a higher capacity to absorb heat for the same change in temperature D) not form hydrogen bonds with each other
Answer: D
The best experimental design _____. A) includes a large sample size for each condition B) includes a control C) alters only one condition between the controls and the experimental condition D) includes a large sample size and a control, and alters only one condition between the controls and the experimental condition
Answer: D
The experimental approach taken in current biological investigations presumes that _____. A) simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can be synthesized only by living organisms B) a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods C) living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products D) living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena
Answer: D
The figure above shows the structures of glucose and fructose. These two molecules are _____. A) isotopes B) enantiomers C) cis-trans isomers D) structural isomers
Answer: D
The molar mass of glucose is 180 grams per mole (g/mol). Which of the following procedures should you carry out to make a 1 M solution of glucose? Into 0.8 liter (L) of water, dissolve _____. A) 1 g of glucose and then add more water until the total volume of the solution is 1 L B) 18 g of glucose and then add more water until the total volume of the solution is 1 L C) 180 g of glucose and then add 0.2 L more of water D) 180 g of glucose and then add more water until the total volume of the solution is 1 L
Answer: D
The two molecules shown in the figure below are best described as _____. A) enantiomers B) radioactive isotopes C) structural isomers D) cis-trans isomers
Answer: D
To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first? A) pH B) density at room temperature C) heat of vaporization D) specific heat
Answer: D
What is the major structural difference between starch and glycogen? A) the types of monosaccharide subunits in the molecules B) the type of glycosidic linkages in the molecule C) whether glucose is in the α or β form D) the amount of branching that occurs in the molecule
Answer: D
What is the name of the functional group shown in the figure below? A) carbonyl B) ketone C) aldehyde D) carboxyl
Answer: D
What results from the chemical reaction illustrated above? The reactants have no charge. A) a cation with a net charge of +1 and an anion with a net charge of +1 B) a cation with a net charge of -1 and an anion with a net charge of -1 C) a cation with a net charge of -1 and an anion with a net charge of +1 D) a cation with a net charge of +1 and an anion with a net charge of -1
Answer: D
When Stanley Miller applied heat and electrical sparks to a mixture of simple inorganic compounds such as methane, hydrogen gas, ammonia, and water vapor, what compounds were produced? A) only simple organic compounds such as formaldehyde and cyanide B) mostly hydrocarbons C) only simple inorganic compounds D) simple organic compounds, amino acids, and hydrocarbons
Answer: D
Which functional group(s) shown above is (are) present in all amino acids? A)Aand B B) B and D C) C only D) B and C
Answer: D
Which molecule shown above contains a functional group that cells use to transfer energy between organic molecules? A)A B) B C) C D) D
Answer: D
Which molecule shown above would have a positive charge in a cell? A)A B) B C) C D) D
Answer: D
Which of the following are compounds? A) H2O, O2, and CH4 B) H2O and O2 C) O2 and CH4 D) H2O and CH4, but not O2
Answer: D
Which of the following combinations of molecules illustrated could be linked to form a nucleotide? A) 1, 2, and 11 B) 3, 7, and 8 C) 5, 9, and 10 D) 11, 12, and 13
Answer: D
Which of the following dissociates completely in solution and is considered to be a strong base (alkali)? A) HCl B) NH3 C) H2CO3 D) NaOH
Answer: D
Which of the following is (are) true of natural selection? A) It requires genetic variation. B) It results in descent with modification. C) It involves differential reproductive success. D) It requires genetic variation, results in descent with modification, and involves differential reproductive success.
Answer: D
Which of the following is a FALSE statement concerning amino groups? Amino groups _____. A) are basic with respect to pH B) are found in amino acids C) contain nitrogen D) are nonpolar
Answer: D
Which of the following is the strongest evidence that protein structure and function are correlated? A) Proteins function best at certain temperatures. B) Proteins have four distinct levels of structure and many functions. C) Enzymes tend to be globular in shape. D) Denatured (unfolded) proteins do not function normally.
Answer: D
Which of the following is true of carbon? A) It forms only polar molecules. B) It can form a maximum of three covalent bonds with other elements. C) It is highly electronegative. D) It can form both polar and nonpolar bonds.
Answer: D
Which of the following statements is true about buffer solutions? A) They maintain a constant pH when bases are added to them but not when acids are added to them. B) They maintain a constant pH when acids are added to them but not when bases are added to them. C) They fluctuate in pH when either acids or bases are added to them. D) They maintain a relatively constant pH when either acids or bases are added to them.
Answer: D
Which of the groups shown above is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules? A)A B) B C) C D) D
Answer: D
Which one of the atoms shown would be most likely to form an anion with a charge of -1? *Answers are diagrams showing the amount of electrons
Answer: D
Why is carbon so important in biology? A) It is a common element on Earth. B) It has very little electronegativity, making it a good electron donor. C) It bonds to only a few other elements. D) It can form a variety of carbon skeletons and host functional groups.
Answer: D
You have a freshly prepared 0.1 M glucose solution. Each liter of this solution contains how many glucose molecules? A) 6.02 × 1023 B) 3.01 × 1023 C) 6.02 × 1024 D) 6.02 × 1022
Answer: D
You need to represent a molecule to best illustrate the relative sizes of the atoms involved and their interrelationships. Which representation would work best? A) molecular formula B) structural formula C) ball-and-stick model D) space-filling model
Answer: D