BIO MIDTERM CH1-5 Flashcards
1) Which of the following statements about the leopard is false? A) Leopards are the largest cat in the genus Panthera. B) Leopards, like lions, can roar. C) Leopards prefer to eat their kill in trees. D) Leopards are well-adapted for nocturnal hunting. E) Leopards are normally solitary animals.
A) Leopards are the largest cat in the genus Panthera.
Life is organized in a hierarchical fashion. Which of the following sequences correctly lists that hierarchy as it increases in complexity? A) ecosystem, population, organ system, cell, community, molecule, organ, organism, tissue B) cell, molecule, organ system, organ, population, tissue, organism, ecosystem, community C) organism, organ system, tissue, population, organ, community, cell, ecosystem, molecule D) molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem E) ecosystem, molecule, cell, tissue, organism, organ system, organ, community
D) molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem
What is the difference between a tissue and an organ system? A) The tissue level of organization is more inclusive than the organ system level. B) Tissues are not composed of cells; organ systems are composed of cells. C) A tissue cannot exist unless it is a component of an organ system, whereas an organ system can exist independently of tissues. D) An organ system includes tissues. E) Tissues are not considered to be living; organ systems are considered to be living.
D) An organ system includes tissues.
The tree in your backyard is home to two cardinals, a colony of ants, a wasp’s nest, two squirrels, and millions of bacteria. Together, all of these organisms represent A) a species. B) a community. C) a population. D) an ecosystem. E) the biosphere.
B) a community.
) If you eat a hamburger, you are mainly eating ground-up beef muscle. What levels of organization are represented in this ground-up muscle? A) organism, population, and community B) organ, organ system, and organism C) community, ecosystem, and biosphere D) organelle, cell, and tissue E) tissue, organ, and organ system
D) organelle, cell, and tissue
Which of the following statements about ecosystems is false? A) The “web of relationships” within an ecosystem includes the nonliving components of the environment. B) Bacteria and fungi recycle energy within an ecosystem. C) Plants and other photosynthetic organisms are producers in ecosystems. D) Chemical nutrients cycle within an ecosystem’s structural web. E) In the process of energy conversions within an ecosystem, energy is eventually converted to heat.
B) Bacteria and fungi recycle energy within an ecosystem.
) The ultimate source of energy flowing into nearly all ecosystems is A) wind. B) sunlight. C) electricity. D) geothermal vents. E) radioactivity.
B) sunlight.
A consumer eating a producer represents A) a transfer of chemical nutrients and energy. B) a transfer of chemical nutrients but not a transfer of energy. C) a transfer of energy but not a transfer of chemical nutrients. D) neither a transfer of chemical nutrients nor a transfer of energy.
A) a transfer of chemical nutrients and energy.
Which of the following statements regarding a common cellular activity is false? A) Cells respond to the environment. B) Cells develop and maintain complex organization. C) Cells take in and use energy. D) Cells regulate their internal environment. E) New cells are derived from cellular components like organelles.
E) New cells are derived from cellular components like organelles.
Your instructor asks you to look into your microscope to see a prokaryotic cell. You will be looking for a cell that A) has a nucleus. B) has a membrane. C) makes up most of the tissues of your body. D) is much larger than most cells in your body. E) does not use DNA to code genetic information.
B) has a membrane.
Which of the following statements about genetics is true? A) Genes are proteins that produce DNA. B) Each organism has its own unique DNA code. C) DNA relies upon five different building blocks as the alphabet of inheritance. D) Differences among organisms reflect different nucleotide sequences in their DNA. E) Each DNA molecule is a single strand of nucleotides.
D) Differences among organisms reflect different nucleotide sequences in their DNA.
Which of the following statements about the properties of life is false? A) All organisms have a complex organization. B) All organisms have the ability to take in energy and use it. C) All organisms have the ability to respond to stimuli from the environment. D) All organisms have the ability to reproduce. E) All organisms have the ability to maintain a constant internal temperature.
D) All organisms have the ability to reproduce.
Which of the following statements about living systems is false? A) Living systems are composed of two or more cells. B) Living systems maintain a relatively consistent internal environment. C) Living systems respond to changes in the environment. D) Living systems encode their genetic information in DNA. E) Living systems grow and develop.
A) Living systems are composed of two or more cells.
Organisms that are prokaryotes are in the domains A) Bacteria and Archaea. B) Plantae and Animalia. C) Eukarya and Archaea. D) Archaea and Plantae. E) Fungi and Bacteria.
A) Bacteria and Archaea.
Which of the following statements about the domain Bacteria is true? A) All bacteria are “animal-like” in that they eat other organisms. B) All bacteria have a membrane-bound nucleus. C) All bacteria are multicellular organisms. D) All bacteria lack a nucleus. E) All bacteria are “animal-like” in that they eat other organisms, and all bacteria have a membrane-bound nucleus.
D) All bacteria lack a nucleus.
Members of the kingdom Animalia A) can obtain their food either by absorption or by photosynthesis. B) are composed of cells that lack a cell membrane. C) are composed of cells that are surrounded by a cell wall. D) can obtain their food by eating other organisms. E) are composed of cells that are surrounded by a cell wall and that lack a cell membrane.
D) can obtain their food by eating other organisms.
What feature is common to prokaryotes, fungi, and plants? A) a nucleus B) single cells C) membership in the kingdom Monera D) cell walls E) photosynthesis
D) cell walls
Which of the following is a kingdom within the domain Eukarya? A) Viruses B) Monera C) Fungi D) Archaea E) Bacteria
C) Fungi
All organisms belonging to the kingdom Plantae A) are photosynthetic. B) contain cells that are surrounded by cell walls with cellulose. C) are unicellular and lack a nucleus. D) lack a nucleus. E) are photosynthetic and contain cells that are surrounded by cell walls with cellulose.
E) are photosynthetic and contain cells that are surrounded by cell walls with cellulose.
Members of the kingdom Fungi A) include the mushrooms. B) include the yeasts. C) decompose the remains of dead organisms and absorb nutrients from the leftovers. D) include the mushrooms and yeasts, and decompose the remains of dead organisms and absorb nutrients from the leftovers. E) use photosynthesis to produce their own food.
D) include the mushrooms and yeasts, and decompose the remains of dead organisms and absorb nutrients from the leftovers.
A scientist examining a group of cells under the microscope notices the presence of nuclei within these cells. Chemical tests reveal that each cell is surrounded by a wall composed of cellulose. These cells must come from an organism that is a member of the kingdom A) Monera. B) Protista. C) Plantae. D) Fungi. E) Animalia.
C) Plantae.
Which of the following observations would provide the strongest evidence that the many different plants we call orchids are actually related to one another? A) The flowers have the same shape of petals. B) They all produce small seeds. C) None of them can grow without the presence of a specific type of fungus. D) They all have the same common ancestor. E) They all attract insect pollinators.
D) They all have the same common ancestor.
The teeth of grain-eating animals (such as horses) are usually broad and ridged. This makes the teeth suitable for grinding and chewing. Meat-eating animals (such as lions) have pointed teeth that are good for puncturing and ripping flesh. This illustrates A) a result of natural selection. B) the connection between form and function. C) a food web. D) that natural selection is not necessary in animals. E) a result of natural selection and the connection between form and function.
E) a result of natural selection and the connection between form and function.
Which of the following statements is not consistent with Darwin’s theory of natural selection? A) Individuals in a population exhibit variations, some of which are heritable. B) Individual organisms exhibit genetic change during their life spans to better fit their environment. C) Factors in the environment result in some organisms with better reproductive success than others. D) Natural selection is based in part on the overproduction of offspring. E) Natural selection can lead to the appearance of new species.
B) Individual organisms exhibit genetic change during their life spans to better fit their environment
) An antibiotic kills 99.9% of a bacterial population. You would expect the next generation of bacteria A) to be just as susceptible to that antibiotic as was the previous generation. B) to be more resistant to that antibiotic. C) to die out due to the drastic decrease in population size. D) to be more contagious than the prior generation. E) to be less virulent than the previous population.
B) to be more resistant to that antibiotic.
Which of the following statements about evolution is true? A) Individuals evolve within the span of their own lifetimes. B) Organisms evolve structures in response to needs. C) Evolution is deliberate and purposeful. D) Evolution is a passive process. E) Evolution is directional.
D) Evolution is a passive process.
Consider the following statement: “If all vertebrates have backbones, and turtles are vertebrates, then turtles have backbones.” This statement is an example of A) a hypothesis. B) discovery science logic. C) rationalization. D) deductive reasoning. E) inductive reasoning.
D) deductive reasoning.
A hypothesis is A) the same as a theory. B) a tentative answer to some question. C) an explanatory idea that is broad in scope and supported by a large body of evidence. D) a widely accepted idea about a phenomenon. E) a widely accepted theory that is broad in scope and supported by a large body of evidence.
B) a tentative answer to some question.
You notice that over the past month, many students on campus have started wearing a new style of school sweatshirt. You think to yourself that perhaps the bookstore has recently started selling this new sweatshirt style. This prediction is an example of A) an experimental question. B) a type of observation. C) a hypothesis. D) an experiment. E) a type of control.
C) a hypothesis.
A theory is A) an idea that has been proven. B) a concept in the early stages that still needs to be tested. C) a belief that has been accepted by all scientists as fact. D) a description of a belief that invokes the supernatural. E) an explanation of an idea that is broad in scope with multiple lines of evidence.
E) an explanation of an idea that is broad in scope with multiple lines of evidence
To be scientifically valid, a hypothesis must be A) phrased as a question. B) based on faith. C) controlled. D) reasonable. E) testable and falsifiable.
E) testable and falsifiable.
The role of a control in an experiment is to A) provide a basis of comparison to the experimental group. B) prove that a hypothesis is correct. C) ensure repeatability. D) prove that a hypothesis is correct and ensure repeatability. E) counteract the negative effect of the experiment.
A) provide a basis of comparison to the experimental group.
A scientist performs a controlled experiment. This means that A) the experiment is repeated many times to ensure that the results are accurate. B) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. C) two experiments are conducted, one differing from the other by only a single variable. D) two experiments are conducted, one differing from the other by two or more variables. E) one experiment is performed, but the scientist controls the variables.
C) two experiments are conducted, one differing from the other by only a single variable.
Which of the following best represents an example of technology? A) figuring out what mountain gorillas eat B) sequencing the human genome C) testing for genetic diseases D) comparing the structure of a human and gorilla arm E) identifying the cause of a new contagious disease
C) testing for genetic diseases
As the environment changes, A) populations change with a purpose. B) populations will become extinct. C) natural selection adapts populations to their environment. D) individuals develop new traits to adapt to the environment. E) new species will evolve by combining traits from several preexisting species.
C) natural selection adapts populations to their environment.
Which level in the hierarchy shown is a community?
A) level A
B) level B
C) level C
D) level D
E) level E
C) level C
Which of the following organisms belongs to the group represented in Box 1?
A) giraffe
B) earthworm
C) tree
D) decomposing bacteria
E) leopard
C) tree
The National Institutes of Health (NIH) set up a study to determine whether large doses of vitamin C would shorten the length of time it takes to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of Group A took 3,000 mg of vitamin C daily. Group B received 3,000 mg of a placebo. At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both Group A and B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in the length of time the colds lasted.
1) Which was the experimental group?
A) Group A only
B) Group B only
C) all 3,000 volunteers
D) half of Group A and half of group B
E) the researchers that inserted the cold virus
A) Group A only
The National Institutes of Health (NIH) set up a study to determine whether large doses of vitamin C would shorten the length of time it takes to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of Group A took 3,000 mg of vitamin C daily. Group B received 3,000 mg of a placebo. At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both Group A and B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in the length of time the colds lasted.
To have confidence that the results of the experiment were valid, you’d also want to know
A) the genders of the volunteers.
B) whether any volunteers had colds at the start of the experiment.
C) whether the volunteers exercised daily.
D) whether the volunteers all worked for the same company.
E) what the volunteers ate during the experiment.
B) whether any volunteers had colds at the start of the experiment.
What phrase best describes the connection between the ants’ use of formic acid and the theme of Chapter 2?
A) Ants are important for the survival of trees.
B) Ants use the trees as a home.
C) Other tree species could benefit from the ants.
D) Chemicals are part of the hierarchical structure of life.
E) Ants and trees can form symbiotic relationships.
D) Chemicals are part of the hierarchical structure of life.
The four most common elements in living organisms are
A) C, H, O, Fe.
B) C, H, O, Na.
C) C, H, O, N.
D) C, N, O, Na.
E) Fe, N, O, Ca.
C) C, H, O, N.
Which of the following is a trace element in the human body?
A) carbon
B) nitrogen
C) zinc
D) oxygen
E) hydrogen
C) zinc
Which of the following statements regarding matter is false?
A) All life is composed of matter.
B) Matter occupies space.
C) Matter has mass.
D) Matter is composed of elements.
E) Matter can be created and destroyed.
E) Matter can be created and destroyed.
Which of the following trace elements is commonly added to table salt to prevent the formation of goiters?
A) iodine
B) iron
C) calcium
D) magnesium
E) fluoride
A) iodine
Which of the following trace elements may be added to bottled water in an effort to prevent tooth decay?
A) nitrogen
B) sodium
C) chlorine
D) potassium
E) fluoride
E) fluoride
Which of the following statements best describes a compound?
A) A compound is a pure element.
B) A compound is less common than a pure element.
C) A compound contains two or more different elements in a fixed ratio.
D) A compound is exemplified by sodium.
E) A compound is a solution.
C) A compound contains two or more different elements in a fixed ratio.
) In the equation 2 H2 + O2 → 2 H2O,
A) H2, O2, and H2O are all compounds.
B) H2, O2, and H2O are all elements.
C) only H2O is a compound.
D) only H2 and O2 are compounds.
E) H2, O2, and H2O are all trace elements.
C) only H2O is a compound.
Which of the following particles is found in the nucleus of an atom?
A) protons and neutrons
B) protons and electrons
C) only neutrons
D) only protons
E) only electrons
A) protons and neutrons
Electrons move about the nucleus of an atom in the same way that
A) insects fly around a bright lamp at night.
B) cars are parked along the sides of a street.
C) boats cross a lake.
D) people pass each other along a sidewalk.
E) birds migrate to a new winter home.
A) insects fly around a bright lamp at night.
What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?
A) 6
B) 8
C) +1
D) 12
E) 18
D) 12
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many electrons does boron have?
A) 11
B) 15
C) 0
D) 5
E) 2
D) 5
Which of the following is another term used for atomic mass?
A) roberts
B) darwin
C) mendel
D) dalton
E) calvin
D) dalton
The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?
A) 0
B) 11
C) 22
D) 23
E) 34
D) 23
Which of the following best describes the atomic number of an atom?
A) the number of protons in the atom
B) the number of electrons in the atom
C) the number of neutrons in the atom
D) the number of protons, electrons, and neutrons in the atom
E) the net electrical charge of the atom
A) the number of protons in the atom
Typically, nitrogen atoms are composed of electrons, protons, and neutrons. An isotope of nitrogen could
A) be positively charged.
B) be negatively charged.
C) have more than electrons and more than protons.
D) have more than protons.
E) have more than neutrons.
E) have more than neutrons.
) A radioactive isotope is an isotope that
A) is stable.
B) decays.
C) has more protons than the common variant of the element.
D) has more electrons than the common variant of the element.
E) has the same atomic mass, but a different atomic number than the common variant of the element.
B) decays.
If you found a fossilized dinosaur bone, what method could be used to determine the age of the fossil?
A) electrophoresis
B) DNA fingerprinting
C) isotope analysis
D) radial immunodiffusion
E) high-pressure liquid chromatography
C) isotope analysis
Which of the following statements about radioactive isotopes is true?
A) The nuclei of radioactive isotopes are unusually stable, but the atoms tend to lose electrons.
B) When given a choice between radioactive and nonradioactive isotopes of the same atom, living cells are more likely to
incorporate the radioactive isotopes into their structures.
C) The tracers typically used for diagnosing medical problems remain radioactive in the body for a number of years, but
give off very low levels of radioactive energy.
D) The energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells.
E) Radioactive elements are natural and therefore not harmful.
D) The energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells.
Based on your understanding of radioactive isotopes and Alzheimer’s disease, what might occur with the use of radioactive isotopes when diagnosing this brain disease?
A) It would not be very accurate.
B) It could cause more cellular damage, worsening the condition.
C) It only works on diseased brains.
D) It would only work if the isotope was stable.
E) Naturally occurring radioactive isotopes will provide accurate results.
B) It could cause more cellular damage, worsening the condition.
) Radioactive isotopes
A) are frequently added to foods as nutritional supplements.
B) can be used in conjunction with PET scans to diagnose diseases.
C) have no effect on living tissue.
D) do not occur naturally.
E) are never incorporated into organic compounds.
B) can be used in conjunction with PET scans to diagnose diseases.
When full, the innermost electron shell of argon contains ________ electrons, and the outermost shell contains ________ electrons.
A) 2 . . . 2
B) 2 . . . 8
C) 4 . . . 8
D) 8 . . . 2
E) 8 . . . 8
B) 2 . . . 8
What happens to an atom if the electrons in the outer shell are altered?
A) The atom becomes radioactive.
B) The atom will disintegrate.
C) The properties of the atom will change.
D) The atom will remain the same.
E) The atom’s characteristics change and it becomes a different element.
C) The properties of the atom will change.
Which particles increase by one as we move from left to right in the elements on the periodic table?
A) neutrons only
B) neutrons and protons
C) electrons only
D) electrons and protons
E) electrons and neutrons
D) electrons and protons
Table salt is formed when
A) chlorine gives an electron to sodium.
B) a hydrogen bond forms between sodium and chlorine.
C) sodium and chlorine share electrons to form a bond.
D) sodium crystals combine with chlorine crystals.
E) sodium donates its single outer electron to chlorine
E) sodium donates its single outer electron to chlorine
The body uses atoms in different ways to accomplish different tasks. For example, one portion of the body’s calcium supply strengthens bones, whereas another portion combines with proteins to stimulate blood clotting after tissue injury. Which of the statements below provides the most logical chemical explanation of calcium’s ability to perform such different functions?
A) The bone contains calcium salts, which are less reactive than the calcium ions found in the blood.
B) The calcium in blood is a more reactive form of the atom and therefore has fewer protons than the calcium in bone.
C) There are many different isotopes of calcium, and the most reactive isotope is found in the bone.
D) The calcium in blood has a lighter atomic mass than the calcium in bone and is in a more reactive form.
E) The calcium in blood has fewer protons, is a more reactive form of the atom, and has a lighter atomic mass than the
calcium in bone.
A) The bone contains calcium salts, which are less reactive than the calcium ions found in the blood.
) Medicines are often administered in pill form. In many cases, the active ingredient of the pill (the drug) is joined to another substance by ________. This forms a(n) ________, which is stable in the dry environment of a pill bottle but dissociates under the wet conditions of the digestive system to release the drug to the body.
A) ionic bonds . . . salt
B) hydrogen bonds . . . base
C) ionic bonds . . . acid
D) covalent bonds . . . salt
E) polar covalent bonds . . . acid or base (depending on the drug)
A) ionic bonds . . . salt
A(n) ________ forms when two atoms share electrons.
A) ion
B) element
C) covalent bond
D) ionic bond
E) hydrogen bond
C) covalent bond
A hydrogen atom has one electron. How many covalent bonds can hydrogen form?
A) one covalent bond
B) four covalent bonds
C) four covalent bonds
D) two ionic bonds
E) two isotonic bonds
A) one covalent bond
What is the fundamental difference between covalent and ionic bonding?
A) In a covalent bond, the partners have identical electronegativity; in an ionic bond, one of them is more electronegative.
B) In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other.
C) In covalent bonding, both partners end up with filled outer electron shells; in ionic bonding, one partner does and the
other does not.
D) Covalent bonding involves only the outermost electron shell; ionic bonding also involves the next electron shell inside
the outermost shell.
E) Covalent bonds form between atoms of the same element; ionic bonds form between atoms of different elements.
B) In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other.
Which of the following statements regarding the oxygen atom of a water molecule is true?
A) Oxygen is more positively charged than the hydrogen atoms.
B) Oxygen attracts electrons less strongly than the hydrogen atoms.
C) Oxygen is more electronegative than the hydrogen atoms.
D) Oxygen is electrically neutral.
E) Oxygen is attracted to the negatively charged atoms of other molecules.
C) Oxygen is more electronegative than the hydrogen atoms.
In a water molecule, hydrogen and oxygen are held together by a(n) ________ bond.
A) double covalent
B) ionic
C) nonpolar covalent
D) hydrogen
E) polar covalent
E) polar covalent
A person shakes up vinegar and oil dressing before pouring it on salads. What is the chemical reason for doing this?
A) Vinegar contains charged water molecules, while oil is neutral and repels water.
B) Vinegar and oil must be mixed to decease the viscosity.
C) Vinegar and oil are oppositely charged, and opposites attract.
D) Oil is composed of fatty acids, which are too large to dissolve in water.
E) Vinegar has a basic pH and is neutralized when mixed with oil.
A) Vinegar contains charged water molecules, while oil is neutral and repels water.
A water molecule (HOH) is held together by
A) an ionic bond.
B) a single covalent bond.
C) a double covalent bond.
D) two polar covalent bonds.
E) hydrogen bonds.
D) two polar covalent bonds.
The hydrogen atoms of a water molecule are bonded to the oxygen atom by ________ bonds, whereas neighboring water molecules are held together by ________ bonds.
A) hydrogen . . . ionic
B) hydrogen . . . polar covalent
C) polar covalent . . . hydrogen
D) ionic . . . covalent
E) polar covalent . . . ionic
C) polar covalent . . . hydrogen
________ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bonds within and around large molecules.
A) Ionic bonds
B) Covalent bonds
C) Polar covalent bonds
D) Hydrogen bonds
E) Anionic bonds
D) Hydrogen bonds
Water molecules stick to other water molecules because
A) water molecules are neutral, and neutral molecules are attracted to each other.
B) hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
C) covalent bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water
molecules.
D) the hydrogen atoms of adjacent water molecules are attracted to one another.
E) the oxygen atoms of adjacent water molecules are attracted to one another.
B) hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
The tendency of water molecules to stick together is referred to as
A) adhesion.
B) polarity.
C) cohesion.
D) transpiration.
E) evaporation.
C) cohesion.
Which of the following is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides water?
A) the evaporative cooling of skin surfaces
B) the movement of water from the roots of a tree to its leaves
C) the milder temperatures of coastal regions compared to inland areas
D) the ability of certain insects to walk on the surface of water
E) the universality of water as a solvent
E) the universality of water as a solvent
Water’s surface tension and heat storage capacity is accounted for by its
A) orbitals.
B) weight.
C) hydrogen bonds.
D) mass.
E) size.
C) hydrogen bonds.
As ice melts,
A) hydrogen bonds are broken.
B) water molecules become less tightly packed.
C) the water becomes less dense.
D) covalent bonds form.
E) heat is released.
A) hydrogen bonds are broken.
Which of the following will contain more heat but has a lower temperature?
A) a gas-powered lawnmower engine after it has been used for an hour
B) an Olympic-sized heated indoor swimming pool
C) the water used in a dishwasher
D) the boiling water in a pot for noodles
E) a hot air balloon
B) an Olympic-sized heated indoor swimming pool
The temperature of evaporation is much higher for water than for alcohol. Without knowing more about the chemistry of alcohol, which of the following is the most logical chemical explanation for this phenomenon?
A) Ionic bonds form between alcohol molecules. These are the weakest type of bond and are easier to break than the
hydrogen bonds between water molecules.
B) Alcohol has a higher surface tension than water. This means that alcohol molecules can easily break away from other
alcohol molecules and evaporate at a lower temperature.
C) Alcohol molecules are more cohesive than water molecules. This means that as alcohol molecules evaporate, they pull
other alcohol molecules into the air along with them.
D) Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break
away from solution and enter the air.
E) Water is a better solvent than alcohol. Therefore, alcohol can break covalent bonds easily and will not be restricted
from evaporating from its solute.
D) Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break
away from solution and enter the air.
Which of the following statements about water is false?
A) Ice is less dense than liquid water.
B) The hydrogen bonds in ice are less stable than the hydrogen bonds in liquid water.
C) Water naturally exists in all three physical states on Earth.
D) Floating ice on a pond insulates the liquid water below, slowing its rate of freezing.
E) If ice sank, the oceans would eventually freeze solid.
B) The hydrogen bonds in ice are less stable than the hydrogen bonds in liquid water.
You’ve made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following statements is true?
A) You’ve just prepared an aqueous solution.
B) The water is the solute portion of the drink.
C) The instant coffee and sugar are solvents.
D) The instant coffee and sugar dissolve because they have no charged regions to repel the partial positive and partial
negative regions of the water molecules.
E) The coffee and sugar would not dissolve in cold water.
A) You’ve just prepared an aqueous solution.
Clot formation in our blood can lead to a heart attack or stroke. What was altered in the proteins that made the clot?
A) The proteins became more polar.
B) The blood was saturated with proteins.
C) The proteins were no longer soluble in the blood.
D) A different solvent other than water was used.
E) The proteins became more soluble in the blood.
C) The proteins were no longer soluble in the blood.
A pharmaceutical company hires a chemist to analyze the purity of the water being used in its drug preparations. If the water is pure, the chemist would expect to find
A) only molecules of H2O.
B) H2O molecules and H+ ions.
C) H2O molecules and OH- ions.
D) H2O molecules, H+ ions, and OH- ions.
E) only H+ ions and OH- ions.
D) H2O molecules, H+ ions, and OH- ions.
A solution with a pH of 7 is
A) strongly acidic.
B) weakly acidic.
C) neutral.
D) weakly basic.
E) strongly basic.
C) neutral.
Compared to a solution of pH 3, a solution of pH 1 is
A) 100 times more acidic.
B) 10 times more acidic.
C) neutral.
D) 10 times more basic.
E) 100 times more basic.
A) 100 times more acidic.
Which of the following statements about pH is true?
A) The pH scale is a measure of oxygen ion concentration.
B) A single unit change on the pH scale is equivalent to a 1% change in hydrogen ion concentration.
C) An increase in hydrogen ion concentration means a decrease in pH scale units.
D) Basic pH levels are less than 7.
E) The pH of solutions inside most cells is close to 9.0.
C) An increase in hydrogen ion concentration means a decrease in pH scale units.
Household ammonia has a pH of 12; household bleach has a pH of 13. Which of the following statements about them is true?
A) Both of these substances are strong acids.
B) The ammonia has 10 times as many OH- ions as the bleach.
C) The ammonia has 10 times as many H+ ions as the bleach.
D) A solution that could buffer the bleach and ammonia would remove excess OH- ions.
E) The ammonia has 10 times as many OH- ions as the bleach, and a solution that could buffer the bleach and ammonia
would remove excess OH- ions.
C) The ammonia has 10 times as many H+ ions as the bleach.
A buffer
A) is an acid that is used to offset overly basic conditions in the body.
B) is a base that is used to offset overly acidic conditions in the body.
C) donates OH- ions when conditions become too acidic and accepts OH- ions when conditions become too basic.
D) donates H+ ions when conditions become too basic and accepts H+ ions when conditions become too acidic.
E) donates OH- ions when conditions become too basic and accepts OH- ions when conditions become too acidic.
D) donates H+ ions when conditions become too basic and accepts H+ ions when conditions become too acidic.
A diabetic, who does not utilize insulin properly, will metabolize fats instead of glucose. A condition called diabetic ketoacidosis is a common result of excessive fat metabolism, causing blood pH values of 7.1 or less (normal range = 7.35 — 7.45). What has happened to the blood pH and why?
A) The pH is above normal (basic) because the ketones are too basic.
B) The pH is below normal (acidic) because the buffering capacity was exceeded.
C) The pH is above normal (basic) because the glucose is polar.
D) The pH is not affected because the blood buffers can absorb the excess H+.
E) The pH is below normal because buffers can donate OH+.
B) The pH is below normal (acidic) because the buffering capacity was exceeded.
Which of the following statements about acid precipitation is false?
A) Acid precipitation can occur with rain, snow, or fog.
B) Acid precipitation is defined as having a pH below 5.6.
C) Acid precipitation damages natural wilderness areas.
D) Acid precipitation is primarily the result of burning fossil fuels.
E) Acid precipitation has little or no effect on soil chemistry.
E) Acid precipitation has little or no effect on soil chemistry.
The emission of ________ and ________ are primarily responsible for acid precipitation.
A) carbon dioxide . . . methane
B) CFCs . . . bromides
C) nitrogen oxides . . . sulfur oxides
D) halones . . . CFCs
E) carbon dioxide . . . ozone
C) nitrogen oxides . . . sulfur oxides
Which of the following would be considered an effective way to decrease the production of acid precipitation?
A) Drive more full-size SUVs.
B) Build more coal-generated electricity power plants.
C) Discourage the use of alternative energy resources such as solar, wind, and geothermal energy.
D) Whenever possible, walk or ride a bicycle instead of driving a car.
E) Consume only organically grown foods.
D) Whenever possible, walk or ride a bicycle instead of driving a car.
What is likely to happen to wild salmon prices if the burning of fossil fuels continues at the current rate?
A) Prices will drop to pre-fossil fuel burning levels.
B) Prices will increase due to decreased salmon harvests.
C) Prices will stay the same because fossil fuel has nothing to do with salmon.
D) Prices will fluctuate wildly due to illogical fear in the marketplace.
E) Prices will initially decline and then stabilize.
B) Prices will increase due to decreased salmon harvests.
Which of the following statements regarding chemical reactions is false?
A) Chemical reactions involve the making and breaking of chemical bonds.
B) Some chemical reactions create electrons; others destroy them.
C) The atoms of the reactants are exactly the same as the atoms of the products.
D) The reactants contain the same number of atoms as the products.
E) Although the atoms of a reaction’s reactants and products are identical to each other, their molecular formulae differ.
B) Some chemical reactions create electrons; others destroy them.
Which of the following hypotheses would be supported if liquid water were found on Mars and contained evidence of bacteria-like organisms?
A) Life must evolve in the presence of oxygen.
B) The chemical evolution of life is possible.
C) Life on Earth must have originated on Mars.
D) Life is guided by intelligent design.
E) Life spontaneously arises from the decaying flesh of organisms.
B) The chemical evolution of life is possible.
In the equation 2 H2 + O2 → 2 H2O, the H2 molecules are ________ and the H2O molecules are ________.
A) reactants . . . products
B) products . . . reactants
C) created . . . destroyed
D) used . . . stored
E) destroyed . . . created
A) reactants . . . products
Photosynthesis requires many steps to make glucose. As a result of the synthesis process,
A) all the carbons from the six carbon dioxide atoms are found in glucose.
B) more atoms are present at the beginning than at the end.
C) more carbon dioxide is released from the plant than is absorbed.
D) water is synthesized by the plant from H2 and O2.
E) more water is released from the leaves than is absorbed through the roots.
A) all the carbons from the six carbon dioxide atoms are found in glucose.
What change is occurring in this figure?
A) Sodium is gaining an electron.
B) Chlorine is losing an electron.
C) Sodium is becoming negatively charged.
D) Sodium is filling its third electron shell.
E) Chlorine is filling its third electron shell.
E) Chlorine is filling its third electron shell.
The hydrogen bonds shown in this figure are each
A) between two hydrogen atoms.
B) between two oxygen atoms.
C) between an oxygen and a hydrogen atom of the same water molecule.
D) between an oxygen and a hydrogen atom of different water molecules.
E) between two atoms with the same charge.
D) between an oxygen and a hydrogen atom of different water molecules.
You’ve been experiencing acid indigestion lately, and you’d like a quick fix for the problem. You do a little research on the Internet and discover that your problem is caused by excess stomach acid. In the pharmacy aisles, however, you’re having a little trouble deciding what to purchase to address the problem. At the pharmacy counter, the clerk recommends that you purchase Pepcid-AC® or Alka-Seltzer® tablets.
If you could check the pH of the recommended tablets, you would expect it to be
A) higher than 7.
B) lower than 7.
C) exactly 7.
D) pH neutral.
E) either C or D.
A) higher than 7.
You’ve been experiencing acid indigestion lately, and you’d like a quick fix for the problem. You do a little research on the Internet and discover that your problem is caused by excess stomach acid. In the pharmacy aisles, however, you’re having a little trouble deciding what to purchase to address the problem. At the pharmacy counter, the clerk recommends that you purchase Pepcid-AC® or Alka-Seltzer® tablets.
If you were able to chemically analyze your stomach fluids 30 minutes after taking two tablets, you would find
A) more hydrogen ions.
B) fewer hydrogen ions.
C) the same number of hydrogen ions.
D) that the pH in your stomach has decreased.
E) a greater number of covalent bonds.
B) fewer hydrogen ions.
Lactose intolerance is the inability to
A) produce milk proteins.
B) produce lactose.
C) digest cellulose.
D) digest lactose.
E) digest milk fats.
D) digest lactose.
Lactose intolerance
A) is common in people of all ages, from infancy to adulthood.
B) is most common in people of European descent.
C) can currently be treated by gene therapy to treat the underlying cause.
D) does not affect the consumption of beverages made from soy or rice.
E) is a fatal disease with no known treatment.
D) does not affect the consumption of beverages made from soy or rice.
Organic compounds
A) always contain nitrogen.
B) are synthesized only by animal cells.
C) always contain carbon.
D) can be synthesized only in a laboratory.
E) always contain oxygen.
C) always contain carbon.
4) Which of the following statements regarding carbon is false?
A) Carbon has a tendency to form covalent bonds.
B) Carbon has the ability to bond with up to four other atoms.
C) Carbon has the capacity to form single and double bonds.
D) Carbon has the ability to bond together to form extensive, branched, or unbranched “carbon skeletons.”
E) Carbon has the capacity to form polar bonds with hydrogen.
E) Carbon has the capacity to form polar bonds with hydrogen.
You now know that the old cliché “oil and water don’t mix” is true. Why?
A) Oil exhibits polarity and water does not.
B) Water exhibits polarity and oil does not.
C) Oil is hydrophilic.
D) Water is hydrophobic.
E) Oil is an organic compound and water is not.
B) Water exhibits polarity and oil does not.
Which of the following statements about hydrocarbons is false?
A) Hydrocarbons are inorganic compounds.
B) Hydrocarbons are composed of a linked chain of carbon atoms, called a carbon skeleton.
C) Hydrocarbons contain only carbon and hydrogen atoms.
D) Hydrocarbons consist of atoms linked by single and double bonds.
E) Hydrocarbons can form straight, branched or ringed structures.
A) Hydrocarbons are inorganic compounds.
Propanol and isopropanol are isomers. This means that they have
A) the same molecular formula, but different chemical properties.
B) different molecular formulas, but the same chemical properties.
C) the same molecular formula and the same chemical properties.
D) the same number of carbon atoms, but different numbers of oxygen and hydrogen atoms.
E) the same molecular formula, but represent different states of the compound.
A) the same molecular formula, but different chemical properties.
A hydroxyl group is
A) also called a carbonyl group.
B) characteristic of proteins.
C) hydrophobic.
D) characteristic of alcohols.
E) basic.
D) characteristic of alcohols.
Which of the following is a carboxyl group?
A) CO
B) OH
C) NH2
D) COOH
E) SH
C) NH2
Which of the following is an amino group?
A) OH
B) NH2
C) COOH
D) CO
E) CH3
B) NH2
Which of the following statements about the functional groups of organic compounds is false?
A) Functional groups help make organic compounds hydrophilic.
B) Many biological molecules have two or more functional groups.
C) Functional groups participate in chemical reactions.
D) All functional groups include a carbon atom of the organic compound’s skeleton.
E) Functional groups help make organic compounds soluble in water.
D) All functional groups include a carbon atom of the organic compound’s skeleton.
Which of the following contains a carboxyl and an amino group?
A) amino acids
B) fats
C) sugars
D) ATP
E) vinegar
A) amino acids
Which of the following functional groups is capable of regulating gene expression?
A) OH
B) NH2
C) COOH
D) CO
E) CH3
E) CH3
Which of the following statements about the monomers and polymers found in living organisms is false?
A) Cells typically make all of their macromolecules from a set of 40-50 common monomers and a few other ingredients
that are rare.
B) The monomers used to make polymers are essentially universal.
C) Monomers serve as building blocks for polymers.
D) DNA is built from just four kinds of monomers.
E) Monomers are joined together by the process of hydrolysis.
E) Monomers are joined together by the process of hydrolysis.
Which of the following statements about dehydration synthesis is false?
A) One monomer loses a hydrogen atom, and the other loses a hydroxyl group.
B) Electrons are shared between atoms of the joined monomers.
C) H2O is formed as the monomers are joined.
D) Covalent bonds are formed between the monomers.
E) Animal digestive systems utilize this process to break down food.
E) Animal digestive systems utilize this process to break down food.
The results of dehydration synthesis can be reversed by
A) condensation.
B) hydrolysis.
C) polymerization.
D) the addition of an amino group.
E) the addition of a phosphate group.
B) hydrolysis.
Which list below consists of only polymers?
A) sugars, amino acids, nucleic acids, lipids
B) proteins, lipids, nucleic acids, amino acids
C) proteins, lipids, nucleic acids, polysaccharides
D) proteins, lipids, nucleotides, sugars
E) polysaccharides, lipids, amino acids, nucleic acids
C) proteins, lipids, nucleic acids, polysaccharides
What is the general function of enzymes within a cell?
A) to promote the synthesis of monomers
B) to induce chemical reactions
C) to stop chemical reactions
D) to speed up chemical reactions
E) to reverse the direction of chemical reactions
D) to speed up chemical reactions
The molecular formula of most monosaccharides represents a multiple of
A) CH3O.
B) CH2O.
C) CHO.
D) CHO2.
E) CHO3.
B) CH2O.
A molecule with the formula C55H110O55 is probably a(n)
A) oil.
B) steroid.
C) wax.
D) protein.
E) polysaccharide.
E) polysaccharide.
Many names for sugars end in the suffix
A) -acid.
B) -ose.
C) -hyde.
D) -ase.
E) -ing.
B) -ose.
Sucrose is formed
A) from two glucose molecules.
B) from two monosaccharides through dehydration synthesis.
C) when ionic bonds link two monosaccharides.
D) when water molecules are added to two monosaccharides.
E) when glucose and lactose are combined.
B) from two monosaccharides through dehydration synthesis.
A disaccharide forms when
A) two monosaccharides join by dehydration synthesis.
B) two starches join by dehydration synthesis.
C) two monosaccharides join by hydrolysis.
D) two starches join by hydrolysis.
E) a starch and a monosaccharide join by dehydration synthesis.
A) two monosaccharides join by dehydration synthesis.
High-fructose corn syrup is composed primarily of a polysaccharide called
A) sucrose.
B) starch.
C) hydrocarbon.
D) cellulose.
E) lactose.
B) starch.
Which of the following lists contains only polysaccharides?
A) sucrose, starch, and cellulose
B) starch, amino acids, and glycogen
C) cellulose, starch, and glycogen
D) nucleotides, glycogen, and cellulose
E) fructose, cellulose, and glucose
C) cellulose, starch, and glycogen
Cellulose differs from starch in that
A) the monomers of cellulose are held together by covalent bonds, whereas the monomers of starch are held together by
hydrogen bonds.
B) glycogen is formed by plants and cellulose by animals.
C) most animals cannot break down cellulose, whereas starch is easily digested.
D) starch is made of glucose monomers, whereas cellulose is made of fructose monomers.
E) cellulose is highly branched, whereas starch is unbranched.
C) most animals cannot break down cellulose, whereas starch is easily digested.
Foods that are high in fiber are most likely derived from
A) plants.
B) dairy products.
C) red meats.
D) fish.
E) poultry.
A) plants.
Cows can derive nutrients from cellulose because
A) they produce the enzymes that break down cellulose.
B) they chew their food so thoroughly that cellulose fibers are broken down.
C) their intestinal tract contains cellulose-hydrolyzing microorganisms.
D) they convert cellulose into starch, which is easily broken down in the intestinal tract.
E) their intestinal tract contains termites, which can break down cellulose.
C) their intestinal tract contains cellulose-hydrolyzing microorganisms.
The storage form of carbohydrates is ________ in animals and ________ in plants.
A) starch . . . glycogen
B) glycogen . . . starch
C) cellulose . . . glycogen
D) glycogen . . . cellulose
E) chitin . . . glycogen
B) glycogen . . . starch
Which of the following organisms contain the polysaccharide chitin?
A) animals and plants
B) plants and bacteria
C) fungi and insects
D) insects and plants
E) crustaceans and bacteria
C) fungi and insects
An oil may be converted into a substance that is solid at room temperature by
A) adding hydrogens, decreasing the number of double bonds in the molecules.
B) removing water, causing a dehydration synthesis reaction to occur.
C) removing hydrogens, increasing the number of double bonds.
D) cooling it, so that double bonds form and the fats solidify.
E) adding water and shaking it vigorously.
A) adding hydrogens, decreasing the number of double bonds in the molecules.
A diet high in animal products and hydrogenated vegetable margarine may increase the risk for atherosclerosis. This is because
A) most animal fats are unsaturated and most hydrogenated vegetable margarines contain high levels of steroids.
B) most hydrogenated vegetable margarines are hydrogenated oils and most animal products contain high levels of
phospholipids.
C) most animal fats are used for energy storage and most hydrogenated vegetable margarines contain high levels of
unsaturated fats.
D) most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats.
E) most animal products contain high levels of unsaturated oils and most hydrogenated vegetable margarines contain
anabolic steroids.
D) most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats.
Because water and oil don’t mix, water is not very effective at washing away oily dirt. The ability of soap to mix with both water and oily dirt allows dirt to be washed away. Which statement provides the most logical chemical explanation for this phenomenon?
A) Soap molecules have both positively and negatively charged regions. The positively charged regions are attracted to
water; the negatively charged regions are attracted to oil.
B) Soap molecules have both positively and negatively charged regions. The negatively charged regions are attracted to
water; the positively charged regions are attracted to oil.
C) Soap molecules carry no charge. As a result, soap can form an effective bridge between charged water molecules and
neutral oil molecules.
D) Soap molecules have charged regions and neutral regions. The charged regions are attracted to water molecules; the
neutral regions are attracted to oils.
E) Soap molecules have charged regions and neutral regions. The neutral regions are attracted to water molecules; the
charged regions are attracted to oils.
D) Soap molecules have charged regions and neutral regions. The charged regions are attracted to water molecules; the
neutral regions are attracted to oils.
Fatty acids are
A) composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio.
B) composed of carbon, hydrogen, glycerol, and a phosphate group.
C) hydrophobic.
D) composed of four linked rings.
E) components of DNA.
C) hydrophobic.
Which of the following statements regarding triglyceride molecules is false?
A) Triglycerides consist of three fatty acids attached to a glycerol.
B) Triglycerides are hydrophobic.
C) Triglycerides play a role in energy storage.
D) Triglycerides are a type of fat.
E) Triglycerides are part of a signal pathway.
E) Triglycerides are part of a signal pathway.
Fatty acids with double bonds between some of their carbons are said to be
A) unsaturated.
B) saturated.
C) completely hydrogenated.
D) triglycerides.
E) monoglycerides.
A) unsaturated.
The development of atherosclerotic disease can result from a diet high in
A) fiber.
B) protein.
C) saturated fats.
D) sugars.
E) complex carbohydrates.
C) saturated fats.
If you were to add olive oil to your food as part of a diet to lower your risk of atherosclerotic disease, you would use olive oil that
A) is liquid at room temperature.
B) is hydrogenated.
C) is modified to be solid at room temperature.
D) has lard added to it.
E) contains high levels of trans fats.
A) is liquid at room temperature.
Which of the following statements about animal cell lipids is false?
A) Fats are a form of lipid that function to store energy.
B) Phospholipids are important components of cell membranes.
C) Steroids are lipids that function as signaling molecules.
D) Many lipids function as enzymes.
E) Cholesterol is a type of lipid that is a component of cell membranes and steroid hormones.
D) Many lipids function as enzymes.
A phospholipid is composed of
A) one glycerol molecule linked to three fatty acids.
B) one fatty acid molecule linked to three glycerol molecules.
C) one glycerol molecule linked to three phosphate groups.
D) one fatty acid molecule linked to one glycerol molecule and two phosphate groups.
E) one glycerol molecule linked to one phosphate group and two fatty acids.
E) one glycerol molecule linked to one phosphate group and two fatty acids.
Which of the following substances is a lipid?
A) DNA
B) glucose
C) cellulose
D) steroids
E) enzymes
C) cellulose
A major type of lipid found in cell membranes is
A) cellulose.
B) triglycerides.
C) phospholipids.
D) glycerol.
E) waxes.
C) phospholipids.
Which of the following statements about anabolic steroids is false?
A) They cause a general buildup of muscle mass.
B) They often cause the body to reduce its normal output of sex hormones.
C) They chemically resemble testosterone.
D) They promote bone growth.
E) They can stimulate mood swings and violent behavior.
D) They promote bone growth.
Which of the following statements about enzymes is false?
A) They increase the rate of chemical reactions.
B) They function as chemical catalysts.
C) They regulate virtually all chemical reactions in a cell.
D) They are produced by cells.
E) They are monomers used to build proteins.
E) They are monomers used to build proteins.
Which one of the following would be correctly classified as a protein?
A) cholesterol
B) starch
C) enzymes
D) cellulose
E) liposaccharide
C) enzymes
Structural proteins
A) include receptor molecules.
B) respond to environmental changes.
C) include hemoglobin.
D) anchor cell parts.
E) bond to hormones.
D) anchor cell parts.
A scientist suspects that the food in an ecosystem may have been contaminated with radioactive nitrogen over a period of months. Which of the following substances could be examined for radioactivity to test the hypothesis?
A) the cell walls of plants growing in the ecosystem
B) the hair produced by humans living in the ecosystem
C) the sugars produced during photosynthesis by plants growing in the ecosystem
D) the cholesterol in the cell membranes of organisms living in the ecosystem
E) the adipose tissue from animals living in the ecosystem
B) the hair produced by humans living in the ecosystem
Amino acids can be distinguished from one another by
A) the number of R groups found on the amino acid molecules.
B) the chemical properties of their R groups.
C) the type of bond between the R group and the rest of the amino acid molecule.
D) the chemical properties of their amino and carboxyl groups.
E) the number of alpha carbons present in the amino acid molecules
B) the chemical properties of their R groups.
Proteins differ from one another because
A) the peptide bonds linking amino acids differ from protein to protein.
B) the sequence of amino acids in the polypeptide chain differs from protein to protein.
C) each protein contains its own unique sequence of sugar molecules.
D) the number of nucleotides found in each protein varies from molecule to molecule.
E) the number of nitrogen atoms in each amino acid varies.
B) the sequence of amino acids in the polypeptide chain differs from protein to protein.
Glucose molecules are to starch as ________ are to proteins.
A) oils
B) amino acids
C) fatty acids
D) monosaccharides
E) lards
B) amino acids
Peptide bonds
A) are used to form amino acids.
B) form between fatty acids.
C) are formed by a hydrolysis reaction.
D) link amino acids.
E) bind monosaccharides.
D) link amino acids.
Which of the following characteristics of protein will remain intact if the protein is denatured?
A) the shape of the protein
B) the function of the protein
C) the solubility of the protein in water
D) the number of amino acids in the protein
E) the binding properties of the protein
D) the number of amino acids in the protein
Proteins cannot be denatured by
A) heat.
B) changes in pH.
C) chemicals that destroy hydrogen bonds.
D) changes in salt concentration.
E) freezing.
E) freezing.
The primary structure of a protein is
A) an α helix or a pleated sheet.
B) the amino acid sequence of the polypeptide chain.
C) composed of two or more polypeptide chains.
D) maintained by hydrogen bonds.
E) composed of irregular folds.
B) the amino acid sequence of the polypeptide chain.
Which of the following is an example of secondary structure in a protein?
A) a particular amino acid sequence
B) an alpha helix
C) a globular shape
D) the joining of two polypeptide chains
E) a fibrous shape
B) an alpha helix
The tertiary structure of a polypeptide refers to
A) its size.
B) the presence of pleated sheets.
C) the amino acids of which it is made.
D) the overall three-dimensional structure.
E) the number of R groups it contains.
D) the overall three-dimensional structure.
A protein containing more than one polypeptide chain exhibits the ________ level of protein structure.
A) primary
B) secondary
C) tertiary
D) quaternary
E) infinite
D) quaternary
Mad cow disease serves as an example of how interdependent ________ and ________ are to protein.
A) solubility . . . texture
B) form . . . construction
C) structure . . . function
D) adaptability . . . development
E) validity . . . reliability
C) structure . . . function
Which of the following statements regarding nucleotides is false?
A) Nucleotides have a nitrogenous base backbone.
B) Nucleotides contain sugar molecules.
C) Nucleotides contain phosphate groups.
D) Nucleotides can be linked together to form nucleic acids.
E) Nucleotides contain nitrogenous bases.
A) Nucleotides have a nitrogenous base backbone.
Which of the following options correctly pairs a polymer and its monomer?
A) cellulose, amino acids
B) triglyceride, steroid
C) DNA, nucleotides
D) collagen, nucleic acids
E) RNA, ribose
C) DNA, nucleotides
DNA differs from RNA because DNA
A) contains thymine in place of uracil.
B) consists of a single rather than a double polynucleotide strand.
C) contains the sugar ribose rather than the sugar deoxyribose.
D) contains phosphate groups not found in RNA.
E) is always double-stranded, while RNA is never double-stranded.
A) contains thymine in place of uracil.
Genetic information is encoded in the
A) quaternary structure of a protein.
B) sequence of nucleotides in DNA.
C) degree of saturation of fatty acids.
D) length of glycogen.
E) linear sequence of amino acids in a polypeptide.
B) sequence of nucleotides in DNA.
You work for a company that manufactures food products. A new “wonder food” is being distributed by a rival company. The researchers in your company determine that the “wonder food” contains only carbon, oxygen, and hydrogen. At this point, your researchers can say with certainty that the food
A) includes proteins.
B) includes nucleic acids.
C) could only be made of triglycerides.
D) could only be made of carbohydrates.
E) does not include proteins or nucleic acids.
E) does not include proteins or nucleic acids.
In what part of the world did the mutation for lactose tolerance first appear?
A) Eastern Asia
B) South America
C) Northern Europe
D) North America
E) Western Australia
C) Northern Europe
Why did the lactose tolerance mutation in the East African herders spread so rapidly within the population?
A) Milk provided calcium for strong bones.
B) It was a selective advantage for survival during droughts.
C) Lactose was a better source of energy than glucose.
D) Milk was a good source of protein during the winter.
E) Milk from cows could be used to feed infants instead of breast milk.
B) It was a selective advantage for survival during droughts.
These two molecules are structural isomers. What is the difference between them?
A) the number of carbon atoms
B) the number of oxygen atoms
C) the number of hydrogen atoms
D) the location of a double-bonded oxygen atom
E) Only one of them has a double bond between carbon atoms.
D) the location of a double-bonded oxygen atom
How are these two amino acids attached together?
A) amino group to amino group
B) amino group to carboxylic acid group
C) carboxylic acid group to carboxylic acid group
D) carbon atom to carbon atom
E) through a hydrolysis reaction
B) amino group to carboxylic acid group
You’re the manager of a factory that produces enzyme-washed blue jeans (the enzymes lighten the color of the denim, giving a “faded” appearance). When the most recent batch of fabric came out of the enzyme wash, however, the color wasn’t light enough to meet your standards. Your quality control laboratory wants to do some tests to determine why the wash enzymes didn’t perform as expected.
Which hypothesis is most likely to be productive for their initial investigation?
A) The nucleotide chain of the enzymes may be incorrectly formed.
B) The dye in the fabric may have hydrolyzed the fatty acids in the enzymes.
C) The polysaccharides in the enzymes may have separated in the wash water.
D) The three-dimensional structure of the proteins may have been altered.
E) There may not have been enough phospholipids for the volume of fabric.
D) The three-dimensional structure of the proteins may have been altered.
You’re the manager of a factory that produces enzyme-washed blue jeans (the enzymes lighten the color of the denim, giving a “faded” appearance). When the most recent batch of fabric came out of the enzyme wash, however, the color wasn’t light enough to meet your standards. Your quality control laboratory wants to do some tests to determine why the wash enzymes didn’t perform as expected.
Based on your understanding of enzyme structure, which of the following would you recommend that they also investigate?
A) the temperature of the liquid in the washing vat
B) the pH of the liquid in the washing vat
C) the manufacturer of the fabric
D) how long the fabric has been in storage
E) the primary structure of the enzyme
A) the temperature of the liquid in the washing vat
Which of the following statements about cells is true?
A) All cells have cell walls.
B) All cells have internal structures that move.
C) All cells are attached to other cells.
D) All cells are motile.
E) All cells have static organelles.
B) All cells have internal structures that move.
Light microscopes
A) can generally magnify objects about 10,000 times without blurring.
B) typically provide more resolution than an electron microscope.
C) work by reflecting electrons off the surface of an object being studied.
D) use light and glass lenses to magnify an image.
E) are generally not used to view bacteria.
D) use light and glass lenses to magnify an image.
One centimeter = ________ millimeters.
A) 0.01
B) 0.10
C) 10
D) 100
E) 1,000
C) 10
Resolution is the
A) ability of an optical instrument to show two close objects as separate.
B) size of an image.
C) ability of an optical instrument to magnify an image.
D) ability of an optical instrument to estimate the size of an image.
E) distance between the lenses of a microscope.
A) ability of an optical instrument to show two close objects as separate.
Which of the following statements about electron microscopes is true?
A) Electron microscopes focus electron beams to create a magnified image of an object.
B) Scanning electron microscopes are used to study the details of internal cell structure.
C) Electron microscopes use glass lenses to focus and magnify the image.
D) Transmission electron microscopes are mainly used to study cell surfaces.
E) Specimens must be sectioned to be viewed under a scanning electron microscope.
A) Electron microscopes focus electron beams to create a magnified image of an object.
A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which of the following instruments would be best, and why?
A) a light microscope, because it allows observations of whole, live cells
B) a transmission electron microscope, because it has high resolution
C) a transmission electron microscope, because it is capable of very high magnification
D) a scanning electron microscope, because it can reveal structures on cell surfaces
E) a scanning electron microscope, because it can be used to observe whole cells without slicing them
A) a light microscope, because it allows observations of whole, live cells
The idea that all living things are composed of cells and that all cells come from other cells defines
A) central dogma.
B) the laws of inheritance.
C) organelle theory.
D) cell theory.
E) inheritance of acquired characteristics.
D) cell theory.
A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which one of the following instruments would be best?
A) a transmission electron microscope
B) a scanning electron microscope
C) a fluorescence confocal microscope
D) a differential interference-contrast microscope
E) an inverted light microscope
B) a scanning electron microscope
A scanning electron microscope is used to study ________, whereas a transmission electron microscope is used to study ________.
A) live cells . . . dead cells
B) cell surfaces . . . internal cell structures
C) dead cells . . . live cells
D) internal cell structures . . . cell surfaces
E) plant tissue . . . animal tissue
B) cell surfaces . . . internal cell structures
The diameter of most animal and plant cells ranges from
A) 0.01 to 0.1 micrometers.
B) 0.1 to 1.0 micrometers.
C) 1.0 to 10 micrometers.
D) 10 to 100 micrometers.
E) 100 to 1000 micrometers.
D) 10 to 100 micrometers.
As cell size increases, the
A) volume and surface area decrease.
B) volume increases faster than the surface area.
C) surface area increases faster than the volume.
D) surface area and volume increase at the same rate.
E) surface area decreases while the volume remains constant.
B) volume increases faster than the surface area.
Which of the following cells has the greatest surface-to-volume ratio?
A) bacterium
B) human red blood cell
C) human muscle cell
D) frog egg
E) ostrich egg
A) bacterium
Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?
A) Break the cough drop into little pieces and put them all in your mouth. Since each little piece must be dissolved
separately, the drop will last longer.
B) Keep the cough drop whole. This maintains the largest surface-to-volume ratio, and slows the dissolution of the cough drop.
C) Break the cough drop into little pieces and put them all in your mouth. This decreases the surface-to-volume ratio,
and slows the dissolution of the cough drop.
D) It doesn’t matter if the cough drop is in one piece or many pieces; the total amount of cough drop is all that matters.
E) Break the cough drop into little pieces, put them all in your mouth, and drink plenty of water.
B) Keep the cough drop whole. This maintains the largest surface-to-volume ratio, and slows the dissolution of the cough drop.
A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation
A) should present no problem to the cell, since it can continue to perform all other necessary functions.
B) should present no problem to the cell, because the surface area of the cell will increase as the volume of the cell
increases.
C) will eventually be problematic, since the cell’s ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs.
D) should be beneficial, since the cell will be able to divert the ATP normally used for cell division to other processes.
E) will eventually lead to the cell’s deterioration, since functional organelles will not proportionally increase with the size
of the cell.
C) will eventually be problematic, since the cell’s ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs.
Archaea are composed of ________ cells.
A) plant
B) prokaryotic
C) bacterial
D) eukaryotic
E) animal
B) prokaryotic
Which of the following structures is exclusively associated with prokaryotic cells?
A) a membrane-bound nucleus
B) nucleoid
C) a cell wall
D) membrane-enclosed organelles
E) ribosomes
B) nucleoid
The nucleoid region of a prokaryotic cell
A) contains the cell’s DNA.
B) separates the RNA from the cytoplasm.
C) is surrounded by a nucleoid membrane.
D) contains the cell’s nucleoli.
E) is the site of organelle production.
A) contains the cell’s DNA.
________ cells lack a membrane-enclosed nucleus.
A) Plant
B) Animal
C) Prokaryotic
D) Eukaryotic
E) Fungal
C) Prokaryotic
A bacterial cell’s DNA is found in its
A) ribosomes.
B) nucleus.
C) peroxisome.
D) nucleoid region.
E) capsule.
D) nucleoid region.
Which of the following structures are used by prokaryotes for attaching to surfaces?
A) pili
B) flagella
C) capsules
D) anchoring junctions
E) both pili and capsules
E) both pili and capsules
The membranous compartmentalization of a cell
A) divides the cell into two equal-sized halves.
B) allows different metabolic processes to occur simultaneously.
C) requires the presence of a cell wall.
D) requires the presence of a large central vacuole.
E) is common in prokaryotes and eukaryotes.
B) allows different metabolic processes to occur simultaneously.
Which of the following statements about internal membranes in eukaryotic cells is false?
A) In eukaryotic cells, internal membranes greatly increase a cell’s total membrane area.
B) In eukaryotic cells, internal membranes provide an additional area for many metabolic processes occur.
C) In eukaryotic cells, internal membranes form membranous compartments called organelles.
D) In eukaryotic cells, internal membranes contain proteins essential for metabolic processes.
E) In eukaryotic cells, internal membranes standardize the internal environment of all cellular organelles.
E) In eukaryotic cells, internal membranes standardize the internal environment of all cellular organelles.
You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells
A) are plant cells.
B) are animal cells.
C) are bacterial cells.
D) could be either plant or bacterial cells.
E) could be plant, animal, or bacterial cells.
A) are plant cells.
Unlike animal cells, plant cells have ________ and ________. Unlike plant cells, animal cells have ________.
A) chloroplasts . . . cell walls . . . centrioles
B) centrioles . . . chloroplasts . . . cell walls
C) chloroplasts . . . cell walls . . . cell membranes
D) chloroplasts . . . cell walls . . . a nucleus
E) centrioles . . . cell walls . . . large central vacuoles
A) chloroplasts . . . cell walls . . . centrioles
Which of the following statements about cellular metabolism is false?
A) Cellular metabolism includes different processes that require different conditions.
B) Cellular metabolism can occur within organelles.
C) Cellular metabolism can involve the synthesis of steroid hormones.
D) Cellular metabolism occurs in animal but not plant cells.
E) Cellular metabolism often occurs on the surfaces of internal membranes.
D) Cellular metabolism occurs in animal but not plant cells.
26) Plasma membranes are permeable to
A) large molecules such as starch.
B) large molecules such as proteins.
C) small ions such as Na+.
D) nonpolar molecules such as CO2.
E) hydrophilic molecules such as glucose.
D) nonpolar molecules such as CO2.
What would you expect to find when looking through a SEM at a cell treated with an enzyme that cleaves proteins at their hydrophilic amino acids?
A) a cell surface that is devoid of any major structures
B) a cell surface covered with polysaccharides
C) a cell surface coated with hydrophilic proteins
D) a cell surface coated with lipids and polysaccharides
E) a cell surface without its outer phospholipid bilayer
A) a cell surface that is devoid of any major structures
The nucleus of a cell
A) is surrounded by a single layer of membrane.
B) is contained within the nucleolus.
C) is the region of the cell where ribosomes are degraded.
D) contains DNA.
E) is the primary location of protein synthesis.
D) contains DNA.
Long fibers of DNA and protein are called
A) chromatin.
B) a nucleolus.
C) a ribosome.
D) a lysosome.
E) a central vacuole.
A) chromatin.
During cell reproduction, chromatin fibers coil up into structures called
A) ribosomes.
B) lysosomes.
C) peroxisomes.
D) chromosomes.
E) nucleoli.
D) chromosomes.
The function of the nucleolus is
A) to manufacture polypeptides.
B) to manufacture ribosomal RNA.
C) intracellular digestion.
D) to store chromatin.
E) to produce H2O2.
B) to manufacture ribosomal RNA.
Protein synthesis requires the use of mRNA, which
A) is made in the nucleolus.
B) directs the degradation of DNA.
C) must be made by the ribosomes.
D) is translated by the ribosomes into the amino acid sequences of proteins.
E) carries the message to the nucleus to synthesize new DNA during cell division.
D) is translated by the ribosomes into the amino acid sequences of proteins.
The plasma cell produces thousands of antibodies per second. What type of intracellular structure would you expect to be very prominent within the cell?
A) nucleus
B) endoplasmic reticulum
C) mitochondria
D) peroxisome
E) microtubules
B) endoplasmic reticulum
Which location in the cell is unlikely to contain ribosomes or ribosomal subunits?
A) nuclear envelope
B) nucleolus
C) plasma membrane
D) endoplasmic reticulum
E) cytoplasm
C) plasma membrane
Which of the following statements regarding the endomembrane system is false?
A) The endomembrane system is involved in the synthesis, storage, and export of important molecules.
B) The endomembrane system includes the rough and smooth endoplasmic reticulum.
C) The endomembrane system includes the nuclear envelope.
D) The endomembrane system is a system of interrelated membranes that are all physically connected.
E) The endomembrane system divides the cell into compartments.
D) The endomembrane system is a system of interrelated membranes that are all physically connected.
The endomembrane system includes all of the following organelles except the
A) plasma membrane.
B) endoplasmic reticulum.
C) peroxisome.
D) Golgi apparatus.
E) lysosome.
C) peroxisome.
Smooth endoplasmic reticulum
A) stores calcium ions in muscle cells.
B) is the major site of carbohydrate synthesis in eukaryotic cells.
C) produces proteins for cell membranes.
D) produces antibodies.
E) helps assemble ribosomes for protein synthesis.
A) stores calcium ions in muscle cells.
The two main functions of the rough endoplasmic reticulum are the production of
A) mitochondria and proteins secreted by the cell.
B) hydrogen peroxide and steroid hormones secreted by the cell.
C) ribosomes and steroid hormones.
D) membrane and proteins secreted by the cell.
E) chromatin and mitochondria.
D) membrane and proteins secreted by the cell.
Secretory proteins are
A) produced by ribosomes on the smooth endoplasmic reticulum.
B) chemically modified in the nucleus.
C) produced by the cell for internal use.
D) released from the cell through the plasma membrane.
E) incorporated into the mitochondrial membrane.
D) released from the cell through the plasma membrane.
The cells that produce hair contain a lot of ________, while the cells that produce the oils that coat the hair contain a lot of ________.
A) smooth endoplasmic reticulum . . . lysosomes
B) rough endoplasmic reticulum . . . smooth endoplasmic reticulum
C) smooth endoplasmic reticulum . . . rough endoplasmic reticulum
D) microbodies . . . lysosomes
E) nuclei . . . chromatin
B) rough endoplasmic reticulum . . . smooth endoplasmic reticulum
The Golgi apparatus
A) is composed of stacks of membranous vesicles that are continuous with one another.
B) stores, modifies, and packages proteins.
C) strings together amino acids to produce proteins.
D) forms fats from glycerols and fatty acids.
E) is the site of carbohydrate breakdown.
B) stores, modifies, and packages proteins.
Which of the following statements regarding the Golgi apparatus is false?
A) The Golgi apparatus works closely with the endoplasmic reticulum.
B) The Golgi apparatus serves as a molecular warehouse and finishing factory.
C) The Golgi apparatus decreases in size when a cell increases its protein production.
D) The Golgi apparatus modifies chemicals received from the endoplasmic reticulum.
E) The Golgi apparatus sorts molecules according to their destination.
C) The Golgi apparatus decreases in size when a cell increases its protein production.
Which of the following statements about lysosomes is false?
A) Lysosomes help to digest worn-out or damaged organelles.
B) Lysosomes synthesize proteins from the recycled amino acids.
C) Lysosomes fuse with food vacuoles to expose nutrients to lysosomal enzymes.
D) Lysosomes destroy harmful bacteria engulfed by white blood cells.
E) Lysosomes recycle materials within the cell.
B) Lysosomes synthesize proteins from the recycled amino acids.
When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will
A) recycle damaged organelles.
B) produce additional ER.
C) undergo cell division.
D) produce replacement lysosomes.
E) undergo self-digestion and die.
E) undergo self-digestion and die.
Tay-Sachs disease results from the malfunction of
A) mitochondria.
B) lysosomes.
C) endoplasmic reticulum.
D) chloroplasts.
E) nucleoli.
B) lysosomes.
Tay-Sachs disease
A) causes an accumulation of lipids in brain cells.
B) involves damage to liver cells.
C) is due to the absence of an enzyme that digests polysaccharides.
D) prevents the breakdown of glycogen.
E) results in an accumulation of triglycerides in the alveoli of the lungs.
A) causes an accumulation of lipids in brain cells.
Which of the following statements about the functions of a plant cell central vacuole is false?
A) The central vacuole of a plant cell may help increase the size of cells by absorbing water.
B) The central vacuole of a plant cell may store pigments that will help attract pollinating insects.
C) The central vacuole of a plant cell may store waste products.
D) The central vacuole of a plant cell may digest chemicals for recycling.
E) The central vacuole of a plant cell may store poisons.
D) The central vacuole of a plant cell may digest chemicals for recycling.
Contractile vacuoles
A) are generally found in protists that inhabit salt water.
B) help in the excretion of excess salt.
C) prevent cells from bursting as a result of the influx of excess water.
D) allow organisms to avoid dehydration by absorbing water from the environment.
E) stimulate the absorption of salt water.
C) prevent cells from bursting as a result of the influx of excess water.
A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they
A) have lost water and shrunk.
B) have gained water and burst.
C) have died of malnutrition.
D) have died because wastes have built up in the cytoplasm.
E) are surviving but are unable to reproduce.
B) have gained water and burst.
Which organelle is involved in the catabolism of fatty acids and the detoxification of alcohol?
A) peroxosome
B) Golgi apparatus
C) smooth ER
D) nucleus
E) ribosomes
A) peroxosome
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following options correctly lists the order of the structures through which insulin passes from its production to its exit from the cell?
A) rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane
B) rough ER, lysosomes, transport vesicles, cell membrane
C) rough ER, Golgi apparatus, smooth ER, cell membrane
D) rough ER, transport vesicles, cell membrane
E) rough ER, transport vesicles, Golgi apparatus, vacuole, cell membrane
A) rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane
The function of mitochondria is
A) cellular respiration.
B) intracellular transport of proteins.
C) lipid synthesis.
D) photosynthesis.
E) intracellular digestion.
A) cellular respiration.
Cyanide inhibits mitochondrial function; as a result, the rate of
A) ATP synthesis increases.
B) ATP synthesis decreases.
C) photosynthesis increases.
D) lipid synthesis increases.
E) protein synthesis increases.
B) ATP synthesis decreases.
The ________ of a mitochondrion is/are an adaptation that increases the surface area and enhances a mitochondrion’s ability to produce ATP.
A) stroma
B) grana
C) intermembrane space
D) cristae
E) matrix
D) cristae
The function of chloroplasts is
A) cellular respiration.
B) intracellular transport of proteins.
C) lipid synthesis.
D) photosynthesis.
E) intracellular digestion.
D) photosynthesis.
The stroma is the
A) thick fluid enclosed by the inner chloroplast membrane.
B) watery fluid enclosed by the inner membrane of a mitochondrion.
C) space between the inner and outer membranes of a chloroplast.
D) space between the inner and outer membranes of a mitochondrion.
E) fluid within the grana.
A) thick fluid enclosed by the inner chloroplast membrane.
Mitochondria differ from chloroplasts in that mitochondria
A) convert solar energy to chemical energy, whereas chloroplasts convert one form of chemical energy to another.
B) contain three different membrane-bound compartments, whereas chloroplasts contain two.
C) contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana.
D) are not found in plants, whereas chloroplasts are not found in animals.
E) produce glucose, whereas chloroplasts break glucose down.
C) contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana.
The endosymbiosis hypothesis proposes that
A) two cells were juxtaposed and one benefited from the other.
B) one cell was dependent on the other for survival.
C) a small cell lived inside a larger cell to the benefit of both cells.
D) a large cell engulfed and digested a smaller cell, exposing its enzymes for use by the larger cell.
E) two cells merged into one cell, improving the enzyme function of the new cell.
C) a small cell lived inside a larger cell to the benefit of both cells.
The endosymbiosis hypothesis is supported by all of the following pieces of evidence, except the fact that
A) mitochondria have circular DNA like prokaryotes.
B) mitochondria synthesize glucose like prokaryotes.
C) chloroplasts have ribosomes like prokaryotes.
D) mitochondria have a double membrane.
E) chloroplasts split like prokaryotes.
B) mitochondria synthesize glucose like prokaryotes.
Microfilaments differ from microtubules in that microfilaments
A) are larger than microtubules.
B) are found only in plants, whereas microtubules are found in plants and animal cells.
C) are mainly composed of actin, whereas microtubules are composed of tubulin.
D) help to anchor organelles, whereas microtubules primarily function to help cells change shape and move.
E) form the inner core of cilia and flagella, whereas microtubules regulate metabolism.
C) are mainly composed of actin, whereas microtubules are composed of tubulin.
Which of the following statements about the cytoskeleton is false?
A) The cytoskeleton helps to support cells.
B) Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
C) The cytoskeleton is composed of three types of fibers: microfilaments, microtubules, and intermediate filaments.
D) The cytoskeleton plays an important role in amoeboid motion.
E) The cytoskeleton includes fibrous and globular proteins.
B) Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
Intermediate filaments
A) guide the movements of chromosomes.
B) are found within cilia and flagella.
C) surround the nucleus.
D) guide the movements of organelles.
E) support the inner mitochondrial membrane.
C) surround the nucleus.
A drug that interferes with microtubule formation is likely to completely disrupt
A) the production of ribosomes.
B) the amoeboid motion of a cell.
C) the function of lysosomes.
D) contraction of muscle cells.
E) the movements of sperm cells.
E) the movements of sperm cells.
Cilia differ from flagella in that
A) cilia are composed of microfilaments and flagella are composed of intermediate filaments.
B) cilia contain nine microtubule doublets surrounding a central pair of microtubules, while flagella contain only nine
microtubule doublets.
C) the protein filaments of cilia are “naked,” while those of flagella are wrapped in an extension of the cell membrane.
D) cilia are typically more numerous and shorter than flagella.
E) cilia are anchored only in the proteins of the cell membrane, while flagella are anchored in a special structure called the
basal body.
D) cilia are typically more numerous and shorter than flagella.
A basal body is
A) composed of nine microtubule triplets surrounding a central pair of microtubules.
B) similar in structure to centrioles.
C) composed of nine microtubule doublets surrounding a central pair of microtubules.
D) identical in structure to cilia.
E) identical in structure to flagella.
B) similar in structure to centrioles.
Dynein arms
A) are present in cilia but not in flagella.
B) are knobs of carbohydrate that are essential to the movement of cilia and flagella.
C) are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets.
D) are the anchoring proteins in basal bodies.
E) join microfilaments to the cell membrane.
C) are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets.
A woman is having trouble becoming pregnant. Examination of her partner’s sperm indicates that dynein arms are missing from the flagella in his sperm cells. A physician explains that this could interfere with fertility by
A) preventing the sperm from attaching to the egg cell.
B) preventing the sperm from swimming to the egg cell.
C) preventing the sperm from producing enough energy to power swimming.
D) interfering with the attachment of the flagella to the sperm.
E) interfering with the ability of the sperm to tolerate the acid conditions in the vaginal canal.
B) preventing the sperm from swimming to the egg cell.
Decreased fertility in men from developed countries may be related to
A) increased exposure to hormone-like chemicals in the environment.
B) decreased flagella motion due to inactivity.
C) increased sperm motility from multiple flagella.
D) decreased metabolic levels from overexposure to UV rays.
E) decreased ATP synthesis from low glucose levels.
A) increased exposure to hormone-like chemicals in the environment.
Most animal cells are
A) surrounded by a cell wall.
B) attached to each other via plasmodesmata.
C) embedded in an endomembrane system.
D) embedded in an extracellular matrix.
E) embedded in a lipid matrix.
D) embedded in an extracellular matrix.
Most cells from multicellular organisms must be attached to their surroundings via integrins. Failure to maintain this contact will usually result in
A) the proliferation of the cell.
B) increased metabolic activity of the cell.
C) the death of the cell.
D) increased communication with other cells.
E) improved autocrine functions.
C) the death of the cell.
Which of the following would be most affected by a mutation that prevented cells from forming tight junctions?
A) attachment of cells to the surrounding matrix
B) direct flow of water and small molecules from one cell to another
C) integrity of the inner lining of the digestive tract
D) attachment of the cytoskeleton to the inside of the plasma membrane
E) attachment of the cell wall of one plant cell to the cell wall of another
C) integrity of the inner lining of the digestive tract
Skin cells are attached to the extracellular matrix by
A) basal bodies.
B) anchoring junctions.
C) tight junctions.
D) communicating junctions.
E) plasmodesmata.
B) anchoring junctions.
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are
A) occluding junctions.
B) anchoring junctions.
C) tight junctions.
D) communicating junctions.
E) plasmodesmata.
D) communicating junctions.
Which of the following statements about plant cell walls is false?
A) Plant cell walls consist of cellulose fibers embedded in a matrix of polysaccharides and proteins.
B) The cell wall of one plant cell is separated from the cell wall of another by a layer of sticky polysaccharides.
C) Plant cell walls are multilayered structures.
D) Plant cell walls protect plant cells by forming an impermeable layer around the cell.
E) Wood is primarily composed of plant cell walls.
D) Plant cell walls protect plant cells by forming an impermeable layer around the cell.
Which of the following statements regarding plasmodesmata is false?
A) Plasmodesmata penetrate plant cell walls.
B) Plasmodesmata are one type of cell junction in plants.
C) Plasmodesmata carry chemical messages between plant cells.
D) Plasmodesmata carry nutrients between plant cells.
E) Plasmodesmata are commonly found in single-celled organisms.
E) Plasmodesmata are commonly found in single-celled organisms.
Which of the following cell structures is associated with the breakdown of harmful substances or substances that are no longer needed by the cell?
A) chloroplasts
B) mitochondria
C) peroxisomes
D) ribosomes
E) centrioles
C) peroxisomes
Which of the following statements regarding cells is false?
A) All cells are enclosed in a membrane that maintains internal conditions different from the surroundings.
B) All cells have a cell wall.
C) All cells can interconvert forms of energy.
D) All cells can interconvert chemical materials.
E) All cells have DNA as their genetic material.
B) All cells have a cell wall.
A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child’s white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding?
A) A defect in the Golgi apparatus prevented the cells from processing and excreting the bacteria.
B) A defect in the rough endoplasmic reticulum prevented the synthesis of the antibodies (defensive proteins) that would have inactivated the bacteria.
C) A defect in the cell walls of the white blood cells permitted bacteria to enter the cells.
D) A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
E) A defect in the surface receptors of the white blood cells permitted bacteria to enter the cells.
D) A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
According to this figure, which of the following is large enough to see in the light microscope?
A) atoms
B) proteins
C) ribosome
D) viruses
E) mitochondria
E) mitochondria
Which part of the mitochondrion shown is its matrix?
A) structure A
B) structure B
C) structure C
D) structure D
E) structure E
E) structure E
The skin is the body’s largest organ. It’s made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The protein melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function.
Based on their function, you would expect melanocytes in the skin to have a higher than usual number of
A) lysosomes.
B) chloroplasts.
C) ribosomes.
D) Golgi bodies.
E) microtubules.
A) lysosomes.
The skin is the body’s largest organ. It’s made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The protein melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function.
The oil from the sebaceous glands is produced by which of the following cell organelles?
A) ribosomes
B) rough endoplasmic reticulum
C) cell membrane
D) smooth endoplasmic reticulum
E) central vacuole
D) smooth endoplasmic reticulum
Many of the enzymes that control a deep-sea firefly squid’s ability to produce light energy from chemical energy are located
A) in membranes.
B) in the nucleus.
C) within chloroplasts.
D) outside of cells.
E) within mitochondria.
A) in membranes.
The fluid mosaic model describes the plasma membrane as consisting of
A) a phospholipid bilayer with embedded carbohydrates.
B) two layers of phospholipids with protein sandwiched between them.
C) a protein bilayer with embedded phospholipids.
D) carbohydrates, proteins, and phospholipids that can drift in the membrane.
E) individual proteins and phospholipids that can drift in a phospholipid bilayer.
E) individual proteins and phospholipids that can drift in a phospholipid bilayer.
Membrane phospholipids
A) have hydrophobic heads that face the center of the membrane and are shielded from water.
B) have hydrophilic tails that face outward and are exposed to water.
C) often have “kinks” in their tails caused by the presence of a double bond between carbons.
D) remain fluid because they are tightly packed against one another.
E) form impermeable layers for cells .
C) often have “kinks” in their tails caused by the presence of a double bond between carbons.
The cholesterol associated with animal cell membranes
A) is attached to membrane proteins and extends into the watery environment surrounding the cell.
B) helps to stabilize the cell membrane at body temperature.
C) makes the cell membrane fluid at room temperature.
D) is an abnormality resulting from a diet high in cholesterol.
E) helps solidify the membranes when the room temperature is below freezing.
B) helps to stabilize the cell membrane at body temperature.
A major function of glycoproteins and glycolipids in the cell membrane is to
A) glue cells together to form tissues.
B) allow the cells of an embryo to sort themselves into tissues and organs.
C) attach the cell membrane to the cytoskeleton.
D) help the cell resist swelling.
E) help the cell retain its shape.
B) allow the cells of an embryo to sort themselves into tissues and organs.
When physicians perform an organ transplant, they choose a donor whose tissues match those of the recipient as closely as possible. Which of the following cell components are being matched?
A) plasma membrane phospholipids
B) plasma membrane proteins
C) cell-surface carbohydrates
D) plasma membrane cholesterols
E) cytoskeletal elements
C) cell-surface carbohydrates
Most of the functions of a cell membrane are performed by
A) glycolipids.
B) proteins.
C) phospholipids.
D) cholesterol.
E) nucleotides.
B) proteins.
Which of the following statements regarding membrane protein function is false?
A) Membrane proteins serve as enzymes.
B) Membrane proteins act as receptors to molecules like hormones.
C) Membrane proteins provide cellular identification tags.
D) Membrane proteins form junctions between cells.
E) Membrane proteins transfer genetic information to the cytoplasm.
E) Membrane proteins transfer genetic information to the cytoplasm.
Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell is called
A) signal transduction.
B) inhibition.
C) competition.
D) self-recognition.
E) selective permeability.
A) signal transduction.
Plasma membranes are selectively permeable. This means that
A) anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy.
B) the plasma membrane allows some substances to enter or leave a cell more easily than others.
C) glucose cannot enter the cell.
D) cholesterol cannot enter the cell.
E) plasma membranes must be very thick.
B) the plasma membrane allows some substances to enter or leave a cell more easily than others.
Which of the following statements regarding membrane function is false?
A) The plasma membrane forms a selective barrier around the cell.
B) The plasma membrane plays a role in signal transduction.
C) The plasma membrane has receptors for chemical messages.
D) The plasma membrane is the control center of the cell.
E) The plasma membrane is involved in self-recognition.
D) The plasma membrane is the control center of the cell.
Small, nonpolar, hydrophobic molecules such as fatty acids
A) easily pass through a membrane’s lipid bilayer.
B) very slowly diffuse through a membrane’s lipid bilayer.
C) require transport proteins to pass through a membrane’s lipid bilayer.
D) are actively transported across cell membranes.
E) usually enter the cell via endocytosis.
A) easily pass through a membrane’s lipid bilayer.
Which characteristic promoted the utilization of lipids as the first cell membrane?
A) spontaneous degradation of the intracellular environment
B) self-assembly into a simple membrane
C) ability to form an impermeable membrane
D) formation of a semi-solid membrane
E) utilization of the hydrophilic nature of lipids
B) self-assembly into a simple membrane
All cells are enclosed by a plasma membrane that is similar in ________ and ________.
A) thickness . . . composition
B) permeability . . . content
C) proteins . . . lipids
D) lucidity . . . texture
E) structure . . . function
E) structure . . . function
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
A) H2O
B) O2
C) CO2
D) Na+
E) a small, nonpolar molecule such as butane (C4H10)
D) Na+
Oxygen crosses a plasma membrane by
A) osmosis.
B) phagocytosis.
C) active transport.
D) pinocytosis.
E) passive transport.
E) passive transport.
Which of the following statements regarding diffusion is false?
A) Diffusion is a result of the kinetic energy of atoms and molecules.
B) Diffusion is driven by concentration gradients.
C) Diffusion requires no input of energy into the system.
D) Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more
concentrated.
E) Diffusion occurs even after equilibrium is reached and no net change is apparent.
D) Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more
concentrated.
Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of
A) exocytosis.
B) phagocytosis.
C) passive transport.
D) active transport.
E) endocytosis.
C) passive transport.
Osmosis can be defined as
A) the diffusion of water.
B) the diffusion of nonpolar molecules.
C) active transport.
D) the diffusion of a solute.
E) endocytosis.
A) the diffusion of water.
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will
A) exhibit a net movement to the side with lower water concentration.
B) exhibit a net movement to the side with higher water concentration.
C) exhibit a net movement to the side with lower solute concentration.
D) exhibit an equal movement in both directions across the membrane.
E) not cross the membrane.
A) exhibit a net movement to the side with lower water concentration.
In the lab, you use a special balloon that is permeable to water, but not sucrose, to make an “artificial cell.” The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?
A) Water will leave the balloon.
B) Water will enter the balloon.
C) Sucrose will leave the balloon.
D) Sucrose will enter the balloon.
E) Sucrose and water will pass across the balloon simultaneously.
A) Water will leave the balloon.
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
A) is isotonic to the protozoan.
B) is hypotonic to the protozoan.
C) is contaminated with pollutants.
D) contains a higher concentration of solutes than the protozoan.
E) is hypertonic to the protozoan.
B) is hypotonic to the protozoan.
A cell that neither gains nor loses water when it is immersed in a solution is
A) isotonic to its environment.
B) hypertonic to its environment.
C) hypotonic to its environment.
D) metabolically inactive.
E) dead.
A) isotonic to its environment.
In a hypotonic solution, an animal cell will
A) lyse.
B) experience turgor.
C) neither gain nor lose water.
D) shrivel.
E) lose water.
A) lyse.
If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?
A) the expulsion of water by the plant cell’s central vacuole
B) the relative impermeability of the plant cell membrane to water
C) the relative impermeability of the plant cell wall to water
D) the fact that plant cells are isotonic to tap water
E) the relative inelasticity and strength of the plant cell wall
E) the relative inelasticity and strength of the plant cell wall
In the lab, you use a special balloon that is permeable to water but not sucrose to make an “artificial cell.” The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the balloon is ________ relative to the solution in the beaker.
A) isotonic
B) hypotonic
C) hypertonic
D) hydrophobic
E) hydrophilic
B) hypotonic
White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs). When looking at a sample of blood for WBCs, would could you do to reduce interference from RBCs?
A) Mix the blood in a salty solution to cause the RBCs to lyse.
B) Mix the blood in an isotonic solution and allow the WBCs to float to the top.
C) Mix the blood with a dye that stains the proteins in the cytoplasm.
D) Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.
E) Mix the blood in a hypertonic solution, which will cause the RBCs to lyse.
D) Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.
A plant cell in a hypotonic solution
A) is turgid.
B) lyses.
C) shrivels.
D) wilts.
E) is flaccid.
A) is turgid.
You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result,
A) you quench your thirst.
B) your cells lyse, due to the excessive intake of salt.
C) your cells become turgid.
D) you dehydrate yourself.
E) your cells lyse from excessive water intake.
D) you dehydrate yourself.
Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.
A) energy and transport proteins . . . down
B) energy . . . down
C) transport proteins . . . down
D) energy and transport proteins . . . against
E) transport proteins . . . against
C) transport proteins . . . down
The molecules responsible for membrane transport are
A) steroids.
B) ATP.
C) phospholipids.
D) carbohydrates.
E) proteins.
E) proteins.
Which of the following statements is true among all types of passive diffusion?
A) Proteins are needed to transport molecules across the membrane.
B) The concentration gradient is the driving force.
C) Only small polar molecules are able to cross the plasma membrane.
D) Only small nonpolar molecules are able to cross the plasma membrane.
E) Ions never cross the plasma membrane by passive transport.
B) The concentration gradient is the driving force.
Which of the following processes can move a solute against its concentration gradient?
A) osmosis
B) passive transport
C) diffusion
D) facilitated diffusion
E) active transport
E) active transport
Which of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings?
A) active transport
B) facilitated diffusion
C) diffusion
D) osmosis
E) passive transport.
A) active transport
Which of the following is a typical feature of an ATP-driven active transport mechanism?
A) The transport protein must cross to the correct side of the membrane before the solute can bind to it.
B) The solute must be phosphorylated before it can bind to the transport protein.
C) The transport protein is irreversibly phosphorylated as transport takes place.
D) The transport protein catalyzes the conversion of ADP to ATP.
E) The solute moves against the concentration gradient.
E) The solute moves against the concentration gradient.
Which of the following statements regarding active transport is false?
A) Active transport uses ATP as an energy source.
B) Active transport can move solutes up a concentration gradient.
C) Active transport requires the cell to expend energy.
D) Active transport is driven by the concentration gradient.
E) Active transport is necessary to allow nerves to function properly.
D) Active transport is driven by the concentration gradient.
Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion?
A) endocytosis
B) exocytosis
C) diffusion
D) pinocytosis
E) passive transport
B) exocytosis
The process of a white blood cell engulfing a bacterium is
A) osmosis.
B) diffusion.
C) receptor-mediated endocytosis.
D) pinocytosis.
E) phagocytosis.
E) phagocytosis.
Phagocytosis is to eating as pinocytosis is to
A) osmosis.
B) drinking.
C) chewing.
D) hydrolysis.
E) lysis.
B) drinking.
Cells acquire LDLs by
A) osmosis.
B) diffusion.
C) receptor-mediated endocytosis.
D) pinocytosis.
E) phagocytosis.
C) receptor-mediated endocytosis.
Kinetic energy differs from chemical energy in that
A) kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement.
B) kinetic energy depends on the movement of atoms, whereas chemical energy depends on the movement of molecules.
C) kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into
heat.
D) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
E) chemical energy is a particular form of kinetic energy.
D) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing
A) chemical energy into kinetic energy.
B) chemical energy into potential energy.
C) kinetic energy into potential energy.
D) kinetic energy into chemical energy.
E) kinetic energy into thermal energy.
A) chemical energy into kinetic energy.
In the reaction A → B + C + heat,
A) there is a net input of energy.
B) the potential energy of the products is greater than that of the reactant.
C) the potential energy of the products is the same as that of the reactant.
D) the potential energy of the products is less than that of the reactant.
E) entropy has decreased.
D) the potential energy of the products is less than that of the reactant.
Which of the following statements regarding thermodynamics is false?
A) Thermodynamics is the study of energy transformations that occur in a collection of matter.
B) The collection of matter under study is called the system.
C) A single cell or the planet Earth could be a thermodynamic system.
D) An open system exchanges both energy and matter with its surroundings.
E) An automobile engine is an example of a closed system.
E) An automobile engine is an example of a closed system.
According to ________, energy cannot be created or destroyed.
A) Aristotle’s first principle
B) the first law of thermodynamics
C) the second law of thermodynamics
D) the third law of thermodynamics
E) Einstein’s law of relativity
B) the first law of thermodynamics
A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates
A) the first law of thermodynamics.
B) the second law of thermodynamics.
C) that some energy is destroyed in every energy conversion.
D) that energy transformations are typically 100% efficient.
E) that thermal energy can be transformed into chemical energy.
B) the second law of thermodynamics.
Which of the following energy transfers is impossible in living systems?
A) light energy to chemical energy
B) chemical energy to kinetic energy
C) potential energy to kinetic energy
D) light energy to potential energy
E) heat to light energy.
E) heat to light energy.
Living systems
A) violate the first law of thermodynamics.
B) violate the second law of thermodynamics.
C) decrease their entropy while increasing the entropy of the universe.
D) are examples of a closed system.
E) are only compelled to follow the first law of thermodynamics.
C) decrease their entropy while increasing the entropy of the universe.
Which of the following processes is endergonic?
A) the burning of wood
B) the release of heat from the breakdown of glucose
C) the synthesis of glucose from carbon dioxide and water
D) the breakdown of glucose
E) cellular respiration
C) the synthesis of glucose from carbon dioxide and water
What is the basic difference between exergonic and endergonic reactions?
A) Exergonic reactions involve ionic bonds; endergonic reactions involve covalent bonds.
B) Exergonic reactions involve the breaking of bonds; endergonic reactions involve the formation of bonds.
C) Exergonic reactions involve the formation of bonds; endergonic reactions involve the breaking of bonds.
D) Exergonic reactions release energy; endergonic reactions absorb it.
E) In exergonic reactions, the reactants have less chemical energy than the products; in endergonic reactions, the opposite is true.
D) Exergonic reactions release energy; endergonic reactions absorb it.
Which of the following statements concerning energy is false?
A) Fireflies are able to take potential energy in the form of food and convert that energy into kinetic energy in the form of heat and light.
B) A gasoline engine converts chemical energy into kinetic energy.
C) Living systems convert heat energy into chemical energy to reduce entropy.
D) Energy transformations in cells are accompanied by the release of heat energy.
E) During photosynthesis, plants convert kinetic energy into chemical energy.
C) Living systems convert heat energy into chemical energy to reduce entropy.
Which of the following examples is classified as a metabolic pathway?
A) protein synthesis
B) osmosis
C) cell lysis
D) spontaneous combustions
E) passive diffusion
A) protein synthesis
When a cell uses chemical energy to perform work, it couples a(n) ________ reaction with a(n) ________ reaction.
A) exergonic . . . endergonic
B) endergonic . . . exergonic
C) exergonic . . . spontaneous
D) spontaneous . . . exergonic
E) endergonic . . . spontaneous
A) exergonic . . . endergonic
Which of the following statements about the ATP molecule is true?
A) It contains two phosphate groups.
B) Extremely stable bonds link the second and third phosphate groups.
C) It contains the six-carbon sugar hexose.
D) It contains a nitrogenous base molecule called adenine.
E) It can be coupled with an exergonic reaction.
D) It contains a nitrogenous base molecule called adenine.
The transfer of a phosphate group to a molecule or compound is called
A) carboxylation.
B) ionization.
C) phosphorylation.
D) hydrogen bonding.
E) hydrogenation.
C) phosphorylation.
Anything that prevents ATP formation will most likely
A) result in cell death.
B) force the cell to rely on lipids for energy.
C) result in the conversion of kinetic energy to potential energy.
D) force the cell to rely on ADP for energy.
E) have no effect on the cell.
A) result in cell death.
ATP can be used as the cell’s energy exchange mechanism because
A) endergonic reactions can be fueled by coupling them with the formation of ATP from ADP.
B) ATP is the most energy-rich small molecule in the cell.
C) endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.
D) the regeneration of ATP from ADP can be fueled by coupling it with endergonic reactions.
E) ATP is a disposable form of chemical energy, used once and then discarded by the cell.
C) endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.
An energy barrier
A) is the amount of energy that must be produced by the reactants to start a chemical reaction.
B) is higher than the energy of activation of a reaction.
C) is lower than the energy of activation of a reaction.
D) prevents the spontaneous decomposition of molecules in the cell.
E) can only be overcome with the use of enzymes.
D) prevents the spontaneous decomposition of molecules in the cell.
The energy required to initiate an exergonic reaction is called
A) exergonic energy.
B) endergonic energy.
C) input energy.
D) hydrolytic energy.
E) the energy of activation.
E) the energy of activation.
Most of a cell’s enzymes are
A) lipids.
B) proteins.
C) amino acids.
D) nucleic acids.
E) carbohydrates.
B) proteins.
When an enzyme catalyzes a reaction,
A) it lowers the activation energy of the reaction.
B) it raises the activation energy of the reaction.
C) it becomes a product.
D) it acts as a reactant.
E) it is used once and discarded.
A) it lowers the activation energy of the reaction.
Substrates bind to an enzyme’s ________ site.
A) reactant
B) allosteric
C) regulatory
D) phosphate
E) active
E) active
The active site of an enzyme is
A) the region of a substrate that is changed by an enzyme.
B) the highly changeable portion of an enzyme that adapts to fit the substrates of various reactions.
C) the region of an enzyme that attaches to a substrate.
D) the region of a product that detaches from the enzyme.
E) the region of the enzyme composed of only a few specific nucleic acids.
C) the region of an enzyme that attaches to a substrate.
Which of the following statements regarding enzyme function is false?
A) An enzyme’s function depends on its three-dimensional shape.
B) Enzymes are very specific for certain substrates.
C) Enzymes are used up in chemical reactions.
D) Enzymes emerge unchanged from the reactions they catalyze.
E) An enzyme binds to its substrate at the enzyme’s active site.
C) Enzymes are used up in chemical reactions.
Which of the following statements regarding enzymes is true?
A) Enzymes are inorganic.
B) An enzyme’s function is unaffected by changes in pH.
C) Enzymes are the reactants in a chemical reaction.
D) Enzymes catalyze specific reactions.
E) All enzymes depend on protein cofactors to function.
D) Enzymes catalyze specific reactions.
A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child’s temperature. Which of the following statements offers the most logical explanation for this action?
A) Elevated body temperature will increase reaction rates in the child’s cells and overload the limited number of enzymes
found in the cell.
B) Elevated body temperatures may denature enzymes. This would interfere with the cell’s abilities to catalyze various
reactions.
C) Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the
body. This will interfere with the ability of enzymes to catalyze vital chemical reactions.
D) Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to
reactants. This would slow vital body reactions.
E) Elevated body temperatures easily break the covalent bonds linking biologically important molecules. This will cause a
general breakdown of cell structures.
B) Elevated body temperatures may denature enzymes. This would interfere with the cell’s abilities to catalyze various
reactions.
Heating inactivates enzymes by
A) breaking the covalent bonds that hold the molecule together.
B) removing phosphate groups from the enzyme.
C) causing enzyme molecules to stick together.
D) changing the enzyme’s three-dimensional shape.
E) inducing the addition of amino acids.
D) changing the enzyme’s three-dimensional shape.
Which of the following substances could be a cofactor?
A) a protein
B) a polypeptide
C) a zinc atom
D) a ribosome
E) collagen
C) a zinc atom
Which of the following is a coenzyme?
A) zinc
B) vitamin B6
C) iron
D) iodine
E) hydrogen ions
B) vitamin B6
Which of the following will have no effect on the rate of an enzyme-catalyzed reaction?
A) temperature
B) pH
C) competitive inhibitors
D) noncompetitive inhibitors
E) net change in energy
E) net change in energy
Inhibition of an enzyme is irreversible when
A) a competitive inhibitor is involved.
B) a noncompetitive inhibitor is involved.
C) the shape of the enzyme is changed.
D) covalent bonds form between inhibitor and enzyme.
E) weak interactions form between inhibitor and enzyme.
D) covalent bonds form between inhibitor and enzyme.
How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor?
A) Competitive inhibitors interfere with the enzyme; noncompetitive inhibitors interfere with the reactants.
B) Competitive inhibitors bind to the enzyme reversibly; noncompetitive inhibitors bind to it irreversibly.
C) Competitive inhibitors change the enzyme’s tertiary structure; noncompetitive inhibitors cause polypeptide subunits to
dissociate.
D) Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.
E) Competitive inhibitors are inorganic substances such as metal ions; noncompetitive inhibitors are vitamins or vitamin
derivatives.
D) Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.
Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of
A) competitive inhibition.
B) noncompetitive inhibition.
C) feedback inhibition.
D) positive feedback.
E) irreversible inhibition.
C) feedback inhibition.
Which figure depicts an animal cell placed in a solution hypotonic to the cell?
A) cell A
B) cell B
C) cell C
D) cell D
E) cell E
A) cell A
Which part of the ATP molecule breaks free of the rest when an ATP molecule is used for energy?
A) part A
B) part B
C) part C
D) part D
E) part E
E) part E
Americans spend up to $100 billion annually for bottled water (41 billion gallons). The only beverages with higher sales are carbonated soft drinks. Recent news stories have highlighted the fact that most bottled water comes from municipal water supplies (the same source as your tap water), although it may undergo an extra purification step called reverse osmosis.
Imagine two tanks that are separated by a membrane that’s permeable to water, but not to the dissolved minerals present in the water. Tank A contains tap water and Tank B contains the purified water. Under normal conditions, the purified water would cross the membrane to dilute the more concentrated tap water solution. In the reverse osmosis process, pressure is applied to the tap water tank to force the water molecules across the membrane into the pure water tank.
After the reverse osmosis system has been operating for 30 minutes, the solution in Tank A would
A) be hypotonic to Tank B.
B) be isotonic to Tank B.
C) be hypertonic to Tank B.
D) contain more minerals than Tank B.
E) move by passive transport to Tank B.
C) be hypertonic to Tank B.
Americans spend up to $100 billion annually for bottled water (41 billion gallons). The only beverages with higher sales are carbonated soft drinks. Recent news stories have highlighted the fact that most bottled water comes from municipal water supplies (the same source as your tap water), although it may undergo an extra purification step called reverse osmosis.
Imagine two tanks that are separated by a membrane that’s permeable to water, but not to the dissolved minerals present in the water. Tank A contains tap water and Tank B contains the purified water. Under normal conditions, the purified water would cross the membrane to dilute the more concentrated tap water solution. In the reverse osmosis process, pressure is applied to the tap water tank to force the water molecules across the membrane into the pure water tank.
If you shut the system off and pressure was no longer applied to Tank A, you would expect
A) the water movement to follow the concentration gradient.
B) the water to reverse flow from B to A.
C) the water to flow in equal amounts in both directions.
D) the water to flow against the concentration gradient.
E) both a and b above to occur.
E) both a and b above to occur.
