1. Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely malfunctioning in this disease?
A) lysosomes
B) Golgi apparatus
C) mitochondria
D) smooth endoplasmic reticulum
Answer: C
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2. Which of the following terms most precisely describes the cellular process of breaking down large molecules into smaller ones?
A) catabolism (catabolic pathways) B) metabolism
C) anabolism (anabolic pathways) D) dehydration
Answer: A
3. Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the bound cyanide is likely to be localized within the .
A) mitochondria B) peroxisomes C) lysosomes
D) smooth endoplasmic reticulum
Answer: A
4. A characteristic 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules is associated with _ . A) bacterial flagella
B) eukaryotic flagella and motile cilia
C) eukaryotic flagella, motile cilia, and nonmotile cilia
D) centrioles and basal bodies
Answer: B
5. Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?
A) membrane proteins of the inner nuclear envelope B) free ribosomes and ribosomes attached to the ER C) components of the cytoskeleton
D) cellulose fibers in the cell wall
Answer: C
6. Which of the following statements describes the first law of thermodynamics? A) Energy cannot be created or destroyed.
B) The entropy of the universe is decreasing. C) The entropy of the universe is constant.
D) Energy cannot be transferred or transformed. Answer: A
7. Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the
A) mitochondria.
B) ribosomes.
C) peroxisomes.
D) lysosomes.
Answer: A
9. Which of the following statements is an important consequence of the first law of thermodynamics for a living organism?
A) The energy content of an organism is constant.
B) An organism ultimately must obtain all of the necessary energy for life from its environment. C) The entropy of an organism decreases with time as the organism grows in complexity.
D) Organisms grow by converting energy into organic matter. Answer: B
10. Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
A) Living organisms do not obey the second law of thermodynamics, which states that the entropy of an organism increases with each energy transformation.
B) The decrease in entropy is associated with growth of an organism. As a consequence of growth, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their increased complexity.
C) As a consequence of growth, the decrease in entropy of the organism is associated with a corresponding decrease in the entropy of the universe.
D) Living organisms are able to transform chemical energy into entropy. Answer: B
11. Which of the following statements is a logical consequence of the second law of thermodynamics?
A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe.
B) If the entropy of a system decreases, there must be a corresponding decrease in the entropy of the universe.
C) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe.
D) Each chemical reaction in an organism must increase the total entropy of the universe. Answer: D
12. Which of the following organelles produces and modifies polysaccharides that will be secreted?
A) lysosome
B) mitochondrion
C) Golgi apparatus
D) peroxisome
Answer:C
Practice Exams Chapters 1-7
Chapter 1
1. Which of the following is an attribute of living things?
a. They must be capable of acquiring adaptations through evolution.
2. Which of the following is not an attribute of living things?
a. All living things require oxygen.
3. What is the appropriate term for an interbreeding group of individuals
of a single type occupying a defined area?
a. Population
4. Emergent properties of living systems are properties that __________.
a. are due to the arrangement and interactions of parts as complexity
increases
5. Which of the following statements best describes when properties
emerge?
a. The whole is greater than the sum of the parts.
6. Which of the following systems does not display emergent properties?
a. None of the listed responses is correct.
7. Which of the following can best be considered a biological system?
a. All of the listed responses are correct.
8. In an ecosystem, nutrients __________ and energy __________.
a. are recycled; flows through
9. The energy used by most organisms for metabolism and growth
ultimately comes from __________.
a. the sun
10. Which of the following is the fundamental unit of structure and function
in living organisms?
a. Cell
11. What is the molecule that is responsible for both the unity and the
diversity of life?
a. DNA
12. How is the information encoded in DNA actually used by organisms?
a. The information in DNA is transcribed to RNA and then usually translated
into protein.
13. Which of the following domains is prokaryotic?
a. Archaea
14. Which type of organisms within the domain Eukarya is composed of
organisms that are generally unicellular (single-celled)?
a. Protists
15. Eukaryotic organisms that decompose dead organisms and absorb the
nutrients are generally found in which kingdom?
a. Fungi
16. Evolution tends to act at which of the following levels?
a. Population
17. Which of the following observations and inferences led Charles Darwin
to his theory of natural selection as a mechanism for evolution?
a. Darwin synthesized his theory of natural selection from all of the listed
observations and inferences.
18. With evolution as the core theme of biology, we can explain traits
shared by organisms as evidence of __________ and traits that differ
among organisms as evidence of __________.
a. descent from a common ancestor; adaptation through natural selection
19. Experimentation is only one part of the process of scientific inquiry, but
it is a very important step because it __________.
a. allows rejection of hypotheses
20. Radon is a radioactive gas that seeps into homes from the soil. It is
thought to be a cause of lung cancer. A research team investigates this
hypothesis. The members of the team gather large amounts of data on basement radon concentrations and lung cancer rates and conclude that the more radon there is in a home, the more likely are people living in the home to develop lung cancer. After the study is published, other researchers criticize it by asserting that the studied neighborhoods with higher radon concentrations also have a higher percentage of older people and a higher percentage of cigarette smokers than the low-radon neighborhoods. Both advanced age and cigarette smoking increase the risk of lung cancer. This criticism, if correct, shows that the radon study suffered from __________.
a. uncontrolled variables
21. Which of the following statements most clearly demonstrates inductive
reasoning?
a. If the animals observed require organic molecules as nutrients, then it can be concluded that all animals require organic molecules as nutrients.
22. A team of scientists has devised a new chemical fertilizer that its members believe will increase crop yields. The team planted three garden plots with corn. The soil was similar in each, and equal amounts of water were applied to each plot. One plot was treated with a common commercial fertilizer, another was treated with the new fertilizer, and the third plot was not given any fertilizer. The experimenters measured yields as bushels of corn from each plot. The plot that did not receive fertilizer was the __________.
a. control plot
23. A hypothesis must be testable to be scientifically valid. Being testable for being true or false means that __________.
a. some conceivable observation or experiment could reveal whether a given hypothesis is incorrect
24. At which point in a study is a scientific investigator most likely to use
deductive reasoning?
a. In establishing a test of a hypothesis
25. Which of the following is outside the realm of scientific inquiry?
a. Addressing ethical dilemmas
26. A company was testing a new drug it thought would help decrease the risk of transmission of viruses from mother to fetus. In an experiment to test the compound, an investigator gave 400 pregnant female rats a small dose of the experimental drug and inoculated each with a type of virus known to cause disease in rats. At the same time, 400 other pregnant rats were given only the virus. Of the rat pups born to the females that received both the virus and the drug, 197 showed no symptoms of the disease; 205 rat pups born to the virus-only females showed symptoms. From these data, we can best conclude __________.
a. that the drug seems to have little effect on viral transmission at the dosage given
27. The best method for determining whether bean plants require sodium is to __________.
a. grow bean plants with and without sodium
28. Repetition of an experiment _________.
a. is necessary before concluding that a given set of results is correct
29. Should an experiment test only one variable at a time? Why or why
not?
a. Yes, an experiment should test only one variable at a time. This ensures
that the experimental outcome is clearly due to one identifiable factor.
30. A scientific theory is __________.
a. a well-supported concept that has broad explanatory power
Chapter 2
1. What is generally true about essential elements and living organisms?
a. Although all forms of life require iron, other elements are required only by
certain species.
2. If you were told that concentrations of trace elements above what is
required by organisms generally have no effect on those organisms,
what would you say?
a. False. Elevated concentrations of some trace elements such as cobalt and
chromium can be toxic.
3. How would you respond to this reasoning? Oxygen is not a greenhouse
gas; therefore, gases containing oxygen—such as ozone, nitrous oxide,
and carbon dioxide—are not greenhouse gases either.
a. False. Compounds can have emergent properties that are very different
from those of the elements that form them.
4. There are __________ naturally occurring elements.
a. 92
5. Which of the following is a trace element?
a. Copper
6. What are the four most abundant elements found in living systems?
a. Hydrogen, oxygen, nitrogen, and carbon
7. Which of the following has negligible mass?
a. Electron
8. Which of the following subatomic particles has appreciable mass but no charge?
a. Neutron
9. The number of protons in an uncharged atom __________.
a. equals the number of electrons
10. An element has eight protons, nine neutrons, and eight electrons. Its atomic number and atomic mass, respectively, are __________.
a. 8 and 17
11. An uncharged atom of nitrogen (atomic number = 7) has __________.
a. seven protons and seven electrons
12. In which of the following will isotopes of an element always differ?
a. Atomic mass
13. A particular carbon isotope has an atomic number of 6 and an atomic mass of 14. The respective numbers of neutrons, protons, and
electrons that this carbon isotope has are __________.
a. 8, 6, and 6
14. Phosphorus-32 (radioactive) has __________ than phosphorus-35
(normal).
a. three fewer neutrons
15. The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of
calcium?
a. An atom with 20 protons, 21 neutrons, and 20 electrons
16. Why are radioactive isotopes useful in scientific research?
a. Because they can be used as tracers to follow particular atoms and molecules through metabolic pathways
17. A neutral atom of chlorine has an atomic number of 17. It has
__________ electrons in its third shell.
a. 8
18. The chemical characteristics or reactivity of an element depend mostly on the __________.
a. number of electrons in its outermost shell
19. Some groups of chemical elements react similarly to one another. For example, the chemistries of sodium and of lithium are similar, as are the chemistries of chlorine and of iodine. These similarities in chemistry result when different elements have similar __________.
a. numbers of outer-shell electrons
20. How many electrons would be present in the valence shell of a sulfur atom (atomic number 16, mass number 32)?
a. Six electrons
21. For most atoms, when does the configuration of electrons make the atom unreactive?
a. When the atom has eight electrons in its outermost shell
22. An atom that normally has __________ in its outer shell would not tend to form chemical bonds with other atoms
a. eight electrons
23. When one or more pairs of valence electrons are shared by two neutral atoms, what type of bond is formed?
a. A covalent bond
24. A covalent bond is likely to be polar if __________.
a. one of the atoms sharing electrons is much more electronegative than the other
25. When the proton number and electron number are unequal, the atom
or molecule __________.
a. is an ion
26. Copper has an atomic number of 29 and a mass number of 64. What would result if an uncharged copper atom lost two electrons?
a. The atomic number would remain 29, the mass number would remain 64, and the atom would be a cation with a +2 charge.
27. The compound CaSO4 ionizes into a calcium ion and a sulfate ion (SO4). Calcium has two electrons in its outer shell. Upon ionization, what would you expect the charge on the sulfate ion to be?
a. –2
28. Ionic bonds form as a result of __________
a. attraction between ions that have opposite charges
29. A hydrogen bond __________
a. is a weak chemical bond
30. When do hydrogen bonds occur?
a. When partial opposite charges on molecules come close enough to attract each other
31. What is the role of van der Waals interactions in biological molecules?
a. Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules.
32. Which molecule has the shape of a completed tetrahedron?
a. Methane (CH4)
33. Pharmaceutical researchers are often interested in blocking particular receptor proteins on cell surfaces. What chemical property of a
molecule would be most important for this type of application?
a. The molecule's shape
34. Which statement is true about chemical reactions?
a. They involve the making and breaking of chemical bonds.
35. Which statement describes a reversible reaction that has reached
chemical equilibrium?
a. The rate of the reverse reaction equals the rate of the forward reaction.
Chapter 3
1. Cells are surrounded by water, with which they are mostly filled. Which of the following occurs as a result?
a. All of the listed responses are correct.
2. Water is a polar molecule. What does this statement mean?
a. That atoms in the molecule have partial charges as a result of unequal sharing of electrons in a covalent bond
3. The partial charges on a water molecule occur because of __________
a. the unequal sharing of electrons between the hydrogen and the oxygen
atoms of a water molecule
4. In a group of water molecules, hydrogen bonds form between which of
the following?
a. The oxygen atom in one water molecule and a hydrogen atom in another
water molecule
5. Which of the following accurately relates the emergent properties of
water to the effects of global warming in the Arctic?
a. Ice floats because it is less dense than liquid water; floating ice insulates
water below and provides a habitat for some species. The significant
increase in Arctic air temperature over the past 50 years is causing a
reduction in sea ice, compromising these beneficial effects of sea ice.
6. If water were not a polar molecule, how would the effects of climatic
warming differ from those currently observed or predicted to occur in
the future?
a. The effects would be drastically worse because the loss of the polar
nature of water would greatly reduce its specific heat and its ability to
moderate temperature.
7. The tendency of water molecules to stay close to each other as a result
of hydrogen bonding __________.
a. is called cohesion, acts to moderate temperature, provides the surface
tension that allows small animals to move across a water surface, and
helps to keep water moving through the vessels in a tree trunk
8. What do cohesion, surface tension, and adhesion have in common with
reference to water?
a. All are properties related to hydrogen bonding.
9. The ability of water molecules to form hydrogen bonds with other
water molecules and water's ability to dissolve substances that have
charges or partial charges are __________.
a. both caused by water's partial charges
10. The phenomenon responsible for maintaining the upward movement of
water through vessels in a tree is __________.
a. cohesion
11. Adhesion is best described as which of the following?
a. The clinging of one substance to another substance
12. You can fill a glass of water to just slightly above the rim without the
water spilling over the glass. What property of water best explains this
phenomenon?
a. Surface tension
13. Which action would involve the greatest transfer of heat?
a. Condensing 5 g of steam to liquid water
14. Imagine that organisms consisted of 70–95% alcohol instead of 70–
95% water. Alcohol's specific heat is about half that of water. How
would living things be different?
a. Systems for temperature regulation would have to be much more efficient.
15. The amount of heat required to change the temperature of 1 g of any
substance by 1°C is defined as __________
a. the specific heat of that substance
16. The amount of heat required to convert 1 g of any substance from the
liquid to the gaseous state is defined as __________.
a. the heat of vaporization of that substance
17. The reason that coastal climates are more moderate than inland
climates primarily water's high __________.
a. specific heat
18. Sweating has a cooling effect because of water's high __________.
a. heat of vaporization
19. Water has __________ than other liquids such as ethanol, reflecting its
capacity to absorb large amounts of heat.
a. a higher boiling point
20. Which of the following occurs because molecules of water are farther
apart in ice than in liquid water?
a. Ice floats
21. Water is a very versatile solvent because water molecules are
__________.
a. polar
22. How does the polarity of water contribute to its ability to dissolve so
many substances?
a. Because it is polar, water's negatively charged oxygen atoms and
positively charged hydrogen atoms are attracted to positively and
negatively charged ions and molecules.
23. What are nonpolar molecules that cluster away from water molecules
called?
a. Hydrophobic
24. A molecule that has all nonpolar covalent bonds would be __________.
a. hydrophobic
25. Why are cell membranes composed primarily of hydrophobic
molecules?
a. In order to perform their function of separating the aqueous solutions
outside cells from the aqueous solutions inside cells, cell membranes
cannot be soluble in water.
26. Sucrose has a molecular mass of 342 daltons. To make a 2-molar (2 M)
solution of sucrose, __________.
a. stir 342 g of sucrose in water to dissolve the sugar, and then add enough
water to bring the total volume of the solution up to 0.5 L
27. A mole of ethyl alcohol weighs 46 g. How many grams of ethyl alcohol
are needed to produce 1 L of a 2-millimolar (2 mM) solution?
a. 0.092 g
28. An acid is __________.
a. a compound that donates hydrogen ions to a solution
29. Adding acid tends to __________ of a solution
a. increase the hydrogen ion concentration and lower the pH
30. Which of the following dissociations is that of an acid?
a. HF → H
+
+ F
–
31. A glass of grapefruit juice, at pH 3, contains __________ H
as a glass of
tomato juice, at pH 4.
a. ten times as much
+
32. A solution at pH 6 contains __________ than the same amount of
solution at pH 8.
a. 100 times more H
+
33. Adding a base tends to __________ of a solution.
a. Lower the hydrogen ion concentration and increase the pH
34. A substance that minimizes changes in the concentration of H
and
OH
+
–
in a solution is a __________.
a. buffer
35. Why is the increasing amount of carbon dioxide being taken up by the
oceans a cause for concern?
a. More carbon dioxide causes an increase in carbonic acid (H2CO3), which
leads to a decrease in the concentration of carbonate ion (CO3
2–
).
36. The absorption of human-generated CO2 by the oceans __________.
a. increases the hydrogen ion concentration in the oceans but decreases the
carbonate ion concentration and threatens the livability of the oceans for
organisms that produce calcium carbonate shells
Chapter 4
1. What are the six most important chemical elements of life?
a. Carbon, nitrogen, oxygen, hydrogen, phosphate, sulfur
2. Using modern equipment, a former graduate student of Stanley Miller
recently reanalyzed the sample results of volcano simulation
experiments that Miller conducted along with his classic experiment
described in the text. This reanalysis did which of the following?
a. Identified additional organic compounds that had not been found by Miller
3. Stanley Miller's experiments were significant because he demonstrated
that __________.
a. a variety of simple organic compounds could be spontaneously
synthesized from components in Earth's primitive atmosphere
4. Which of the following is an organic molecule?
a. CH4
5. What is the three-dimensional shape created by hybrid orbitals that are
formed when a carbon atom is covalently bonded with four other
atoms?
a. A tetrahedron with carbon in the center
6. A pharmaceutical company was forced to recall a pain reliever
medication that had been linked to the fatalities of several hundred
people. Analysis of the recalled drug revealed the presence of two
isomers due to an asymmetrical carbon atom in the drug molecule.
What can be hypothesized from this observation?
a. The isomers are enantiomers, with one having toxic effects on humans.
7. A straight-chain carbon compound constructed from __________ must
contain at least one carbon-carbon double bond.
a. 6 hydrogen atoms and 3 carbon atoms
8. What is the reason carbon atoms are the most versatile building blocks
of the molecules used by living organisms?
a. Each carbon atom acts as an intersection point from which a molecule can
branch off in up to four directions.
9. The carbon atom possesses __________ valence electron(s)
a. 4
10. Which of the following are properties of hydrocarbons?
a. Hydrophobic, nonpolar, good source of stored energy
11. A molecule has one carbon-carbon double bond and four monovalent
atoms or groups. How many different cis-trans isomers exist for this
molecule?
a. Two
12. The two compounds
are related to each other by being __________.
a. hydrocarbons, isomers, organic compounds, and double-bonded
compounds
13. Pharmaceutical companies are selling billions of dollars' worth of
single-enantiomer drugs. Why might it be important to use only one
form of an enantiomer?
a. One enantiomer may provide an effective treatment whereas the other
may be ineffective or even toxic.
14. Which of the following functional groups is present in all amino acids?
a. —NH2
15. Which of these is found in all amino acids?
a. both —COOH and —NH2
16. Ethanol, propanol, and methanol are three simple alcohols. They can
be grouped together because they __________
a. share the same functional group: a hydroxyl
17. Which of the following molecules has a carboxyl functional group?
a. R—COOH
18. Which of the following functional groups increases the solubility of
organic compounds in water?
a. All of the listed responses are correct.
19. Which of the following examples best describes a unique functional
property of the carboxyl group?
a. The covalent bond between oxygen and hydrogen is so polar that
hydrogen ions tend to dissociate from oxygen reversibly.
20. Which of the following functional groups is associated with a release of
energy when removed from the carbon skeleton with water?
a. Phosphate group
21. Which functional group would you predict is part of abscisic acid?
a. Carboxyl group
22. Which of the following groups is capable of hydrogen bonding with an
oxygen atom on another functional group?
a. All of the listed responses are correct.
23. Which of these is a thiol?
a. None of the listed responses is correct.
24. What is ATP's importance in the cell?
a. ATP stores the potential to react with water, thereby removing a phosphate
group and releasing energy for cellular processes.
Chapter 5
1. What is the process by which monomers are linked together to form
polymers?
a. Dehydration reaction
2. In a hydrolysis reaction, __________, and in this process, water is
__________.
a. a polymer is broken up into its constituent monomers; consumed
3. The type of bond that forms to join monomers (such as sugars and
amino acids) into polymers (such as starch and proteins) is a(n)
__________ bond.
a. covalent
4. Generally, animals cannot digest (hydrolyze) the glycosidic linkages
between the glucose molecules in cellulose. How then do cows get
enough nutrients from eating grass?
a. Microorganisms in their digestive tracts hydrolyze the cellulose to
individual glucose units
5. In what polysaccharide form do plants store glucose to be available
later as an energy source?
a. Starch
6. Which of the following molecules is a monosaccharide?
a. C6H12O6
7. At a conference, the speaker's grand finale was sautéing mealworms
(insect larvae) in butter and serving them to the audience. They were
crunchy (like popcorn hulls) because their exoskeletons contain the
polysaccharide __________.
a. chitin
8. Carbohydrates are used in our bodies mainly for __________.
a. energy storage and release
9. The polysaccharide that you are most likely to have eaten recently is
__________
a. starch
10. One characteristic shared by sucrose, lactose, and maltose is that
__________
a. they are all disaccharides
11. A polysaccharide that is used for storing energy in human muscle and
liver cells is _________
a. glycogen
12. Carbohydrates can function in which of the following ways?
a. Structural support and energy storage
13. Amylase is an enzyme that breaks down starch. Why can the same
enzyme not break down cellulose?
a. The monosaccharide monomers in cellulose are bonded together
differently than those in starch.
14. The subunits (monomers) in cellulose are linked together by __________
a. glycosidic linkages
15. Which of the following components of a tossed salad will pass through
the human digestive tract and be digested the least?
a. Cellulose (in the lettuce)
16. Lipids differ from other large biological molecules in that they
__________.
a. re not truly polymers
17. Which of the following terms can be correctly used to describe
compounds that do not mix with water?
a. hydrophobic
18. Nutritionally, saturated triacylglycerols are considered to be less
healthful than unsaturated triacylglycerols. What is the difference
between them?
a. For carbon skeletons of equal length, saturated triacylglycerols have more
hydrogen atoms than unsaturated triacylglycerols do.
19. The lipids that form the main structural component of cell membranes
are _________
a. phospholipids
20. If a small droplet of triacylglycerol molecules is suspended in water,
the fat molecules form a "ball of spaghetti" with no particular
orientation. But if a droplet of phospholipid molecules is put in water,
all the molecules point outward, toward the water. Phospholipids are
forced into this orientation because phospholipids have __________
a. a charged or polar end and an uncharged or nonpolar end
21. Which of the following is a true statement comparing phospholipids
and triacylglycerols (fats and oils)?
a. Phospholipid molecules have a distinctly polar "head" and a distinctly
nonpolar "tail," whereas triacylglycerols are predominantly nonpolar.
22. The sex hormones estradiol and testosterone belong to which class of
molecules
a. Lipids
23. High cholesterol levels are considered a major risk factor for heart
disease. If it is so bad for humans, why does the body make cholesterol
in the first place?
a. Cholesterol is the precursor for many important molecules such as sex
hormones.
24. Manufacturers make vegetable oils solid or semisolid at room
temperature by _________
a. adding hydrogen atoms to the fatty acid hydrocarbon chains, thereby
converting carbon-carbon double bonds to single bonds
25. Some lipids are formed when fatty acids are linked to glycerol. These
subunits are linked together by __________.
a. ester linkages
26. The fatty acid tails of a phospholipid are __________ because they
__________.
a. hydrophobic; have no charges to which water molecules can adhere
27. The overall three-dimensional shape of a single polypeptide is called its
_________
a. tertiary structure
28. When a protein is denatured, why does it lose its functionality
a. Denaturation breaks the intramolecular bonds, such as hydrogen bonds
and van der Waals interactions, that hold the protein in its threedimensional
shape.
Without
the
proper
shape,
the
protein
cannot
function.
29. Which of the following lists ranks these molecules in the correct order
by size from smallest to largest
a. Water, glucose, sucrose, protein
30. Which of the following represents a specific description of a
polypeptide
a. None of the listed responses is correct.
31. Enzyme molecules require a specific shape to perform their catalytic
function. Which of the following might alter the shape of an enzymatic
protein?
a. All of the listed responses are correct.
32. The α helix and β pleated sheet represent which level of protein
structure?
a. Secondary structure
33. The peptide bond is __________
a. a covalent bond joining amino acids together to form a polypeptide
34. Protein molecules are polymers (chains) of __________.
a. amino acid molecules
35. The "primary structure" of a protein refers to _________
a. the sequence of amino acids along a polypeptide chain
36. What do Alzheimer's, Parkinson's, and mad cow disease have in
common?
a. All are associated with the buildup of misfolded proteins in cells.
37. A glucose molecule is to starch as __________
a. a nucleotide is to a nucleic acid
38. A shortage of phosphorus in the soil would make it especially difficult
for a plant to manufacture __________
a. DNA
39. Based on complementary base pairing, you would expect the
percentage of __________ to be equal to the percentage of __________.
a. adenine; thymine
40. Which of the following are pyrimidines found in the nucleic acid DNA?
a. Thymine and cytosine
41. Which of the following describes a difference between DNA and RNA?
a. The first three listed responses correctly describe differences between
DNA and RNA.
42. Which of the following lists represents the chemical components of a nucleotide?
a. A nitrogenous base, a phosphate group, and a pentose sugar
43. Which of the following is true regarding complementary base pairing in DNA and RNA molecules?
a. Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules
Chapter 6
1. Which of the following is the simplest collection of matter that can live?
a. Cell
2. A researcher wants to film the movement of chromosomes during cell
division. Which type of microscope should she choose, and why is it the
best choice?
a. Light microscope because the specimen is alive
3. Which of the following statements is true about cell fractionation?
a. Cell fractionation separates cells into their component parts.
4. Consider two cells with the same volume but with very different
surface areas due to differences in their shapes. The cell with the
larger surface area is likely to __________.
a. be involved in the rapid uptake of compounds from the cell's environment
5. Which of the following is/are likely to limit the maximum size of a cell?
a. All of the choices are correct.
6. Which of the following structures is found in eukaryotic
but not prokaryotic cells?
a. Mitochondria
7. A substance moving from outside the cell into the cytoplasm must pass
through __________.
a. the plasma membrane
8. In terms of cellular function, what is the most important difference
between prokaryotic and eukaryotic cells?
a. Eukaryotic cells are compartmentalized, which allows for specialization
9. Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell, they
__________.
a. have no membrane-bounded organelles in their cytoplasm
10. Which of the following features do prokaryotes and eukaryotes have in
common?
a. Ribosomes, plasma membrane, and cytoplasm
11. A particular cell has a nucleus and chloroplasts in addition to the
fundamental structures required by all cells. Based on this information,
this cell could be __________.
a. a photosynthetic protist cell or a plant cell
12. What is the functional connection between the nucleolus, nuclear
pores, and the nuclear membrane?
a. Subunits of ribosomes are assembled in the nucleolus and pass through
the nuclear membrane via the nuclear pores.
13. Which of the following is false in respect to eukaryotic chromosomes
a. Chromosomes appear in an obvious form only as a cell is about to divide.
14. A dish of animal cells was grown in the presence of radioactive
phosphorous. The phosphorous largely ended up in nucleotides inside
the actively growing animal cells. In which cellular structure or
structures would you predict the majority of the radioactive
phosphorous to accumulate?
a. The nucleus
15. Which of the following groups is primarily involved in synthesizing
molecules needed by the cell?
a. Ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum
16. Which of the following categories best describes the function of the
rough endoplasmic reticulum?
a. Manufacturing
17. You would expect a cell with an extensive Golgi apparatus to _________
a. secrete large amounts of protein
18. A researcher made an interesting observation about a protein made by
the rough endoplasmic reticulum and eventually found in a cell's
plasma membrane. The protein in the plasma membrane was actually
slightly different from the protein made in the ER. The protein was
probably altered in the __________.
a. Golgi apparatus
19. Consider a protein that is made in the rough endoplasmic reticulum.
You observe that when the synthesis of the protein is completed, the
protein is located in the ER membrane. Where else in the cell might
this protein be found?
a. Embedded in the plasma membrane, functioning in the transport of
molecules into the cell
20. Which of the following sequences represents the order in which a
protein made in the rough endoplasmic reticulum might move through
the endomembrane system?
a. Golgi apparatus → lysosome
21. A protein that ultimately functions in the plasma membrane of a cell is
most likely to have been synthesized __________.
a. in the rough endoplasmic reticulum
22. Which of the following five membranes is most likely to have a lipid
composition that is distinct from those of the other four
a. Mitochondrial outer membrane
23. Chloroplasts and mitochondria are thought to be of prokaryotic origin.
One piece of evidence that supports this hypothesis is that these
organelles contain prokaryotic-like ribosomes. These ribosomes are
probably most similar to ribosomes found __________.
a. in bacterial cells
24. Which of the following statements about chloroplasts and mitochondria
is true?
a. Chloroplasts and mitochondria synthesize some of their own proteins.
25. Which type of cell is most likely to have the largest number of
mitochondria?
a. Muscle cells in the legs of a marathon runner
26. Which of the following is false?
a. `Mitochondria contain ribosomes in the intermembrane space.
27. Which of the following organelles might be found inside other
organelles?
a. Ribosomes
28. Microtubules and microfilaments commonly work with which of the
following to perform many of their functions?
a. Golgi apparatus
29. Which of the following structures is found in animal cells but not in
plant cells?
a. Centrioles
30. Which statement about the cytoskeleton is true?
a. Components of the cytoskeleton often mediate the movement of
organelles within the cytoplasm.
31. Cilia and flagella move due to the interaction of the cytoskeleton with
which of the following?
a. Motor proteins
32. Basal bodies are most closely associated with which of the following
cell components?
a. Cilia
33. Dye injected into a plant cell might be able to enter an adjacent cell
through __________.
a. plasmodesmata
34. Your intestine is lined with individual cells. No fluids leak between
these cells from the gut into your body. Why?
a. The intestinal cells are bound together by tight junctions.
35. Which of the following statements correctly describes a common
characteristic of a plant cell wall and an animal cell extracellular
matrix?
a. Both are permeable to water and small solutes.
Chapter 7
1. Which of the following statements about the role of phospholipids in
the structure and function of biological membranes is correct?
a. Phospholipids form a selectively permeable structure.
2. The plasma membrane is referred to as a "fluid mosaic" structure.
Which of the following statements about that model is true?
a. The fluid aspect of the membrane is due to the mobility of phospholipids,
and embedded proteins account for the mosaic aspect.
3. Consider the currently accepted fluid mosaic model of the plasma
membrane. Where in the plasma membrane would cholesterol most
likely be found
a. In the interior of the membrane
4. Which of the following is not a function of membrane proteins?
a. Energy, carbon, and nitrogen storage
5. Which of the following functions of membrane proteins is important in
tissue formation during embryonic development in animals?
a. Membrane proteins with short sugar chains form identification tags that
are recognized by other cells.
6. Which of the following statements concerning carbohydrates
associated with the plasma membrane is correct?
a. Membrane carbohydrates function primarily in cell-cell recognition.
7. Consider the currently accepted fluid mosaic model of the plasma
membrane. Where in the membrane would carbohydrates most likely
be found?
a. On the outside (external) surface of the membrane
8. Which statement about the sidedness of the plasma membrane is
correct?
a. All of the listed responses are correct.
9. Which of the following molecules is most likely to passively diffuse
across the plasma membrane?
a. Carbon dioxide
10. Which of the following would be least likely to diffuse through a plasma
membrane without the help of a transport protein?
a. A large, polar molecule
11. Which of the following statements about passive transport is correct?
a. Passive transport permits the solute to move in either direction, but the net
movement of solute molecules occurs down the concentration gradient of
the molecule.
12. Cells A and B are the same size, shape, and temperature, but cell A is
metabolically less active than cell B, and cell B is actively converting
oxygen to water in cellular respiration. Oxygen will diffuse more rapidly
into cell __________ because __________.
a. B; the diffusion gradient in cell B is steeper
13. Which of the following statements about diffusion is true?
a. It is a passive process.
14. The internal solute concentration of a plant cell is about 0.8 M. To
demonstrate plasmolysis, it would be necessary to suspend the cell in
what solution?
a. 1.0 M
15. A single plant cell is placed in an isotonic solution. Salt is then added to
the solution. Which of the following would occur as a result of the salt
addition?
a. Water would leave the cell by osmosis, causing the volume of the
cytoplasm to decrease.
16. Seawater is hypertonic to cytoplasm in vertebrate cells and in plant
cells. If a red blood cell and a plant cell were placed in seawater, what
would happen to the two types of cells?
a. Both cells would lose water; the red blood cell would shrivel, and the plant
plasma membrane would pull away from the cell wall.
17. Which of these statements describes some aspect of facilitated
diffusion?
a. Facilitated diffusion of solutes may occur through channel or transport
proteins in the membrane.
18. Which of the following is false in regard to facilitated diffusion?
a. Facilitated diffusion requires the hydrolysis of ATP.
19. A selectively permeable membrane separates two solutions. Water is
able to pass through this membrane; however, sucrose (a
disaccharide) and glucose (a monosaccharide) cannot pass. The
membrane separates a 0.2-molar sucrose solution from a 0.2-molar
glucose solution. With time, how will the solutions change?
a. Nothing will happen because the two solutions are isotonic.
20. The concentration of solutes in a red blood cell is about 2%, but red
blood cells contain almost no sucrose or urea. Sucrose cannot pass
through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?
a. A hypertonic sucrose solution
21. Green olives may be preserved in brine, which is a 30% salt solution. How does this method of preservation prevent microorganisms from
growing in the olives? a. A 30% salt solution is hypertonic to the bacteria, so they lose too much water and undergo plasmolysis.
22. Active transport requires an input of energy and can also generate voltages across membranes. Based on this information, which of the following statements is true?
a. The sodium-potassium pump hydrolyzes ATP and results in a net positive change outside the cell membrane.
23. Glucose can be moved into cells via an active transport mechanism when the concentration of glucose inside the cell is higher than the concentration of glucose outside the cell. This active transport mechanism moves glucose and sodium into the cell at the same time. The glucose moves up its gradient and the sodium moves down its gradient. Which of the following statements about this mechanism is accurate?
a. To pump glucose up its concentration gradient, sodium moves down its concentration gradient, and the distribution of sodium ions across the membrane forms an electrochemical gradient that drives this mechanism.
24. Which of the following is a correct difference between active transport and facilitated diffusion?
a. Active transport requires an input of energy, and facilitated diffusion does not.
25. A cell has a membrane potential of –100 mV (more negative inside than outside) and has 1,000 times more calcium ions outside the cell than inside. Which of the following best describes a mechanism by which Ca enters the cell?
a. Facilitated diffusion of Ca 2+ into the cell down its electrochemical gradient
26. Which of the following correctly describes a general property of all electrogenic pumps?
a. Electrogenic pumps create a voltage difference across the membrane.
27. Which of the following statements about cotransport of solutes across a membrane is correct?
a. Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes.
28. Consider the transport of protons and sucrose into a plant cell by the sucrose-proton cotransport protein. Plant cells continuously produce a proton gradient by using the energy of ATP hydrolysis to pump protons out of the cell. Why, in the absence of sucrose, do protons not move back into the cell through the sucrose-proton cotransport protein?
a. The movement of protons through the cotransport protein cannot occur unless sucrose moves at the same time.
29. Which of the following enables a cell to pick up and concentrate a specific kind of molecule?
a. Receptor-mediated endocytosis
30. Which of the following processes and organelles account for the replacement of lipids and proteins lost from the plasma membrane?
a. Exocytosis and smooth ER and rough ER
31. A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via which process?
a. Endocytosis 2+
32. Which of the following pairs correctly matches a membrane transport process to its primary function?
a. Pinocytosis: the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane
Biology 121 Past Questions (2020-2023)
1. Concerning the hydrolysis of biological macromolecules, which of the following is true?
A. Water is used as reactant.
B. Water is generated as product.
C. Hydrolysis reactions are the reverse of condensation reactions.
D. All of the above concerning hydrolysis are true.
E. Only A and C are true of the hydrolysis of a biological macromolecule.
2. All cells fall into one of two broad categories. What are they?
A. Eubacteria and Fungi
B. Eubacteria and Archaea
C. Prokaryotes and Eukaryotes
D. Archaea and Eukaryotes
3. One unique characteristic of Eukaryotic cells is the presence of
A. DNA.
B. ribosomes.
C. RNA.
D. a membrane bound nucleus.
E. a cell wall.
4. To be considered alive an organism MUST be able to
A. photosynthesize. B. reproduce.
C. grow and metabolize. D. A and C.
E. B and C.
5. A Bronsted Lowry acid is a molecule that
A.donates anelectron. B acceptsanelectron. C.donatesaproton. D.acceptsaproton.
6. Where precisely are ribosomes assembled in eukaryotic cells?
A. The Golgi
B. The rough ER C. The nucleus
D. The nucleolus
7. What best describes the nature of the nuclear membrane?
A. A phospholipid monolayer
B. A phospholipid bilayer
C. A phospholipid trilayer
D. A double phospholipid bilayer
8. Are plant cell walls chemically similar to prokaryotic cell walls? How are they the same or different?
A. Yes, Plant and Bacterial cell walls are both composed of peptidoglycans.
B. No, Plant cell walls are made of peptidoglycans and bacterial cell walls are made of cellulose
C. No, Plant cell walls are made of cellulose and bacterial cell walls are made of peptidoglycans.
D. Yes, Plant and Bacterial cell walls are both composed of cellulose.
9. Why are cows able to digest cellulose?
A. Because cows have multiple stomachs.
B. Because cows have the genes to manufacture the enzymes necessary to digest cellulose.
C. Because cows harbor microorganisms in their digestive system that make the enzymes necessary to digest cellulose.
D. None of the above.
E. Both A and C are true.
Questions 10-13 refer to the picture below.
10. What best describes this molecule:
A. An amino acid.
B. A monosaccharide. C. A lipid.
D. An RNA nucleotide.
E. A DNA nucleotide.
11. What best describes the part of the molecule labeled ‘A’?
A. A phosphate group. B. An amino group.
C. A pentose sugar.
D. A carboxyl group. E. A nitrogenous base.
12. What best describes the part of the molecule labeled ‘B’?
A. A phosphate group.
B. An amino group. C. A pentose sugar.
D. A carboxyl group.
E. A nitrogenous base.
13. What best describes the part of the molecule labeled ‘C’?
A. A phosphate group. B. An amino group.
C. A pentose sugar.
D. A carboxyl group.
E. A nitrogenous base.
14. Which of the following are found in all prokaryotic and eukaryotic cells?
A. plasma (cell) membrane
B. ribosomes
C. cell wall
D. All of the above
E. Only A and B are found in both prokaryotes and eukaryotes
15. Which of the following organelles lacks a membrane?
A. ribosome
B. nucleus
C. smooth ER
D. rough ER
16. If exocytosis continued without endocytosis, what would happen to the cell?
A. The surface area of the plasma (cell) membrane would remain constant.
B. The surface area of the plasma (cell) membrane would increase.
C. The surface area of the plasma (cell) membrane would decrease.
17. Which of the following do mitochondria and chloroplasts have in common?
A. Both have an outer membrane, as well as a folded inner membrane. B. Both contain a liquid component (matrix in mitochondria, and stroma in chloroplasts).
C. Both are organelles that have a cell wall.
D. Only A and B are shared in common by mitochondria and chloroplasts.
18. Which of the following is true of lysosomes?
A. Lysosomes are not membrane bound.
B. Lysosomes may be used to break down “worn out” organelles. C. Lysosomes contain enzymes that hydrolyze polymers.
D. Both B and C above are true
19. What is/are the function/s of the extracellular matrix?
A. It provides structural support for ribosomes.
B. It allows individual thylakoids to stick together into a granum.
C. It provides the "glue" that allows cells to adhere to one
another.
D. All of the above. E. A and B.
For questions 20-22 Refer to the picture above:
20. Which structure above (A, B, C) best represents a secondary lysosome?
21. Which structure above (A, B, C) best represents a primary lysosome?
22. Whichstructureabove (A, B,C) best represents an endocytic vesicle?
23. If you repeated Dr. Gorter’s experiment comparing the surface area of red blood cells (RBCs) with the surface area of the phospholipids that compose the plasma membrane of RBCs, which of the following results would support the idea that the cell membrane is a lipid bilayer?
|
|
Total cell surface area of the RBCs (m2 = square meters) |
Total surface area of the phospholipids from the RBCs after lysis |
|
A |
1 m2 |
4 m2 |
|
B |
1 m2 |
3 m2 |
|
C |
1 m2 |
2 m2 |
|
D |
1 m2 |
1 m2 |
|
E |
1 m2
|
0.5 m2
|
24. Which of the following is true of cell membrane fluidity?
A. A cell membrane that is too fluid will not perform its boundary function.
B. A cell membrane that is too solid will not perform its transport function.
C. It may be regulated by varying the amount of saturation of the fatty acids in membrane phospholipids.
D.Alloftheabovearetrueofmembranefluidity.
25. Which of the following is supported by the results of the cell fusion and photo-bleaching experiments we discussed in class?
A. Cell membranes are static and membrane proteins are in fixed positions.
B. Cell membranes are fluid.
C. Integral proteins are made by ribosomes.
D. Integral proteins cannot exit the trans face of the Golgi.
26. Animal cells that had been growing in an incubator at 37°C are suddenly cooled to 20°C. Which of the following is most likely to happen?
A. Initially, the membrane of the cells become more fluid.
B. Initially, the membrane of the cells become less fluid.
C. The fluidity of the membrane will not be affected.
27. (Refer to question 26) In response to being cooled, how will the cells likely respond?
A. By generating membrane phospholipids with shorter fatty acid chains.
B. By generating membrane phospholipids with longer fatty acid chains.
C. Neither A or B will occur.
28. (Refer to question 26) In response to being cooled, how will the cells likely respond?
A. By generating membrane phospholipids with fatty acid chains that have fewer C=C double bonds (unsaturations).
B. By generating membrane phospholipids with fatty acid chains that have more C=C double bonds (unsaturations). C. Neither A or B will occur.
For questions 29-30 Refer to the picture above:
29. Which labeledpart (A,B, C, D) best represents the non-polar part of a phospholipid?
30. The Actin filaments labeled above most likely are a part of what?
A. The cytoskeleton.
B. The endomembrane network. C. The extracellular matrix.
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