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WorksheetsAP Biology Unit 1: Chemistry of Life REVIEW!
Total questions: 93
Worksheet time: 8hrs 45mins
Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level?
organelle, tissue, biosphere, ecosystem, population, organism
cell, community, population, organ system, molecule, organelle
organism, community, biosphere, molecule, tissue, organ
molecule, cell, organ system, population, ecosystem, biosphere
Which of the following is a false statement regarding DNA?
Each chromosome has one very long DNA molecule with hundreds of thousands of genes.
Every cell is enclosed by a membrane.
Every cell uses DNA as its genetic information.
All forms of life are composed of cells that have a membrane-enclosed nucleus.
In terms of the hierarchical organization of life, a bacterium is at the level of organization, whereas a human is at the level of organization.
single-celled organism; multicellular organism
single organelle; organism
organelle; organ system
single tissue; multicellular organism
Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into
the energy of motion.
carbon dioxide and water.
the potential energy of chemical bonds.
The lowest level of biological organization that can perform all the activities required for life is the
organelle–for example, a chloroplast.
cell–for example, a skin cell.
tissue–for example, nervous tissue.
organ system–for example, the reproductive system.
Which of the following is a false statement regarding deoxyribonucleic acid (DNA)?
Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix.
Genes are composed of deoxyribonucleic acid.
DNA is composed of chemical building blocks called nucleotides.
DNA is an enzyme that puts together amino acids to make a protein.
Which of the following statements concerning prokaryotic and eukaryotic cells is not correct?
Prokaryotic cells lack a membrane-bound nucleus.
Prokaryotic cells contain small membrane-enclosed organelles.
Eukaryotic cells contain a membrane-bound nucleus.
DNA, or deoxyribonucleic acid, is present in both prokaryotic cells and eukaryotic cells.
A type of protein critical to all cells is organic catalysts called
feedback inhibitors
enzymes
nutrients
feedback activators
Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of
negative feedback
positive feedback
feedback inhibition
When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of
positive feedback
negative feedback
Prokaryotic and eukaryotic cells generally have which of the following features in common?
a membrane-bounded nucleus
a cell wall made of cellulose
ribosomes
flagella or cilia that contain microtubules
Which of these provides evidence of the common ancestry of all life?
the ubiquitous use of catalysts by living systems
the universality of the genetic code
the structure of the nucleus
the structure of cilia
Charles Darwin proposed a mechanism for descent with modification which stated that organisms of a particular species are adapted to their environment when they possess
non-inheritable traits that enhance their survival in the local environment
non-inheritable traits that enhance their reproductive success in the local environment.
non-inheritable traits that enhance their survival and reproductive success in the local environment.
inheritable traits that enhance their survival and reproductive success in the local environment
Through time, the lineage that led to modern whales shows a change from four -limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by
natural philosophy.
creationism.
the hierarchy of the biological organization of life.
natural selection.
[select all that apply] Evolution is biologyʹs core theme that ties together all the other themes. This is because evolution explains
the unity and diversity of life.
how organisms become adapted to their environment through the differential reproductive success of varying individuals.
why distantly related organisms sometimes resemble each other
explains why some organisms have traits in common.
What is a hypothesis?
the same thing as an unproven theory
a tentative explanation that can be tested and is falsifiable
a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation
a fact based on qualitative data that is testable
Which of these is based on a deduction?
My car wonʹt start.
My carʹs battery is dead.
My car is out of gas.
If I turn the key in the ignition while stepping on the gas pedal, then my car will start.
A controlled experiment is one in which
the experiment is repeated many times to ensure that the results are accurate.
the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.
there are at least two groups, one of which does not receive the experimental treatment.
there are at least two groups, one differing from the other by two or more variables.
Why is it important that an experiment include a control group?
The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results.
The control group provides a reserve of experimental subjects.
A control group is required for the development of an ʺif, thenʺ statement.
Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor.
TRUE OR FALSE: A common form of regulation in which accumulation of an end product of a process slows that process is called positive feedback.
FALSE
TRUE
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?
carbon, sodium, chlorine, nitrogen
carbon, sulfur, phosphorus, hydrogen
oxygen, hydrogen, calcium, sodium
carbon, hydrogen, nitrogen, oxygen
Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates?
nitrogen
calcium
iodine
sodium
Which of the following statements is false?
Atoms of the various elements differ in their number of subatomic particles.
All atoms of a particular element have the same number of protons in their nuclei.
Protons and electrons are electrically charged particles. Protons have one unit of negative charge, and electrons have one unit of positive charge.
Different atomic forms of an element contain the same number of protons but a different number of neutrons. What are these different atomic forms called?
ions
isotopes
neutronic atoms
isomers
How do isotopes of the same element differ from each other?
number of protons
number of electrons
number of neutrons
A covalent chemical bond is one in which
electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged.
protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms.
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms.
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following statements is correct about the atoms in ammonia (NH3)?
Each hydrogen atom has a partial positive charge.
The nitrogen atom has a strong positive charge.
Each hydrogen atom has a slight negative charge.
When two atoms are equally electronegative, they will interact to form
equal numbers of isotopes.
ions.
polar covalent bonds
nonpolar covalent bonds.
Which of the following molecules contains the strongest polar covalent bond?
H2
CO2
H2O
CH4
The ionic bond of sodium chloride is formed when
chlorine gains an electron from sodium.
sodium and chlorine share an electron pair.
sodium and chlorine both lose electrons from their outer valence shells.
sodium gains an electron from chlorine.
What is the difference between covalent bonds and ionic bonds?
Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of electrons between atoms.
Covalent bonds involve the sharing of neutrons between atoms, and ionic bonds involve the sharing of electrons between atoms.
Covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical attraction between atoms.
Which of the following results from a transfer of electron(s) between atoms?
nonpolar covalent bond
polar covalent bond
ionic bond
Which of the following explains most specifically the attraction of water molecules to one another?
nonpolar covalent bond
polar covalent bond
ionic bond
hydrogen bond
Sometimes atoms form molecules by sharing two pairs of valence electrons. When this occurs, the atoms are said to be joined by
a double covalent bond.
an electronegative bond.
a hydrogen bond.
Which of the following best describes chemical equilibrium?
Forward and reverse reactions continue with no effect on the concentrations of the reactants and products.
Concentrations of products are higher than the concentrations of the reactants.
Forward and reverse reactions have stopped so that the concentration of the reactants equals the concentration of the products.
Reactions stop only when all reactants have been converted to products.
A group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone?
a compound with the same number of carbon atoms as the hormone
a compound with the same molecular mass (measured in daltons) as the hormone
a compound with the same three-dimensional shape as part of the hormone
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
hydrogen bonds.
nonpolar covalent bonds.
polar covalent bonds.
ionic bonds.
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
a covalent bond
a hydrogen bond
an ionic bond
a hydrophilic bond
Water is able to form hydrogen bonds because
oxygen has a valence of 2.
the water molecule is shaped like a tetrahedron.
the bonds that hold together the atoms in a water molecule are polar covalent bonds
What gives rise to the cohesiveness of water molecules?
hydrophobic interactions
nonpolar covalent bonds
ionic bonds
hydrogen bonds
Which of the following effects is produced by the high surface tension of water?
Lakes donʹt freeze solid in winter, despite low temperatures.
A water strider can walk across the surface of a small pond.
Organisms resist temperature changes, although they give off heat due to chemical reactions.
Waterʹs high specific heat is mainly a consequence of the
small size of the water molecules.
high specific heat of oxygen and hydrogen atoms.
absorption and release of heat when hydrogen bonds break and form.
Which type of bond must be broken for water to vaporize?
ionic bonds
nonpolar covalent bonds
polar covalent bonds
hydrogen bonds
Hydrophobic substances such as vegetable oil are
nonpolar substances that repel water molecules.
nonpolar substances that have an attraction for water molecules.
polar substances that repel water molecules.
polar substances that have an affinity for water.
When an ionic compound such as sodium chloride (NaCl) is placed in water the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of particles (molecules or ions)?
1 L of 0.5 M NaCl
1 L of 0.5 M glucose
1 L of 1.0 M NaCl
Which of the following solutions has the greatest concentration of hydrogen ions [H+]?
gastric juice at pH 2
vinegar at pH 3
tomato juice at pH 4
Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]?
lemon juice at pH 2
tomato juice at pH 4
seawater at pH 8
Pure, freshly-distilled water has a pH of 7. This means that
there are no H+ ions in the water.
the concentration of H+ ions in the water equals the concentration of OH- ions in the water.
the concentration of H+ ions in the water is 7 times the concentration of OH- ions in the water.
Why are hydrocarbons insoluble in water?
The majority of their bonds are polar covalent carbon-to-hydrogen linkages.
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
They are hydrophilic.
They exhibit considerable molecular complexity and diversity.
A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?
It should dissolve in water.
It should dissolve in a nonpolar solvent.
It wonʹt form hydrogen bonds with water.
Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
an alcohol such as ethanol
a monosaccharide such as glucose
a steroid such as testosterone
an amino acid such as glycine
Amino acids are acids because they always possess which functional group
amino
carboxyl
aldehyde
Which of the following is not a polymer?
glucose
starch
cellulose
chitin
What is the chemical mechanism by which cells make polymers from monomers?
phosphodiester linkages
hydrolysis
dehydration reactions
How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
12
11
10
0
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.
Dehydration reactions can occur only after hydrolysis.
Hydrolysis creates monomers, and dehydration reactions break down polymers
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
C18H36O18
C18H30O15
On food packages, to what does the term ʺinsoluble fiberʺ refer?
cellulose
polypeptides
chitin
Which of the following statements is false for the class of biological molecules known as lipids?
They are soluble in water.
They are an important constituent of cell membranes.
They contain more energy than proteins and carbohydrates.
They are not true polymers.
They contain waxes and steroids.
Which of the following is true regarding saturated fatty acids?
They are the predominant fatty acid in corn oil.
They have double bonds between carbon atoms of the fatty acids.
They are the principal molecules in lard and butter.
They are usually liquid at room temperature.
Which of the following statements is true regarding the molecule illustrated in the figure?
It is a saturated fatty acid.
A diet rich in this molecule may contribute to atherosclerosis.
Molecules of this type are usually liquid at room temperature.
The molecule shown in the figure is a
polysaccharide.
polypeptide.
saturated fatty acid
unsaturated fatty acid.
Why are human sex hormones considered to be lipids?
They are essential components of cell membranes.
They are steroids, which are not soluble in water.
They are made of fatty acids.
All of the following contain amino acids except
hemoglobin
cholesterol
antibodies
enzymes.
insulin
The bonding of two amino acid molecules to form a larger molecule requires
the release of a water molecule.
the release of a carbon dioxide molecule.
the addition of a nitrogen atom.
There are 20 different amino acids. What makes one amino acid different from another?
different carboxyl groups attached to an alpha (α) carbon
different amino groups attached to an alpha (α) carbon
different side chains (R groups) attached to an alpha (α) carbon
Which of the following statements is/are true regarding the chemical reaction illustrated in the Figure?
It is a hydrolysis reaction.
It results in a peptide bond.
It joins two fatty acids together.
The bonding of two amino acid molecules to form a larger molecule requires which of the following?
removal of a water molecule
addition of a water molecule
formation of an ionic bond
Polysaccharides, lipids, and proteins are similar in that they
are synthesized from monomers by the process of hydrolysis.
are synthesized from monomers by dehydration reactions.
are synthesized as a result of peptide bond formation between monomers.
Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids.
How many peptide bonds are present in this protein?
101
100
99
98
At which bond would water need to be added to achieve hydrolysis of the peptide, back to its component amino acid?
A
B
C
D
Which bonds are created during the formation of the primary structure of a protein?
peptide bonds
hydrogen bonds
disulfide bonds
phosphodiester bonds
What maintains the secondary structure of a protein?
peptide bonds
hydrogen bonds
disulfide bonds
ionic bonds
The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure?
primary
secondary
tertirary
The tertiary structure of a protein is the
bonding together of several polypeptide chains by weak bonds.
order in which amino acids are joined in a polypeptide chain.
unique three-dimensional shape of the fully folded polypeptide.
overall protein structure resulting from the aggregation of two or more polypeptide subunits
A strong covalent bond between amino acids that functions in maintaining a polypeptideʹs specific three-dimensional shape is a (an)
ionic bond.
hydrophobic interaction.
disulfide bond
hydrogen bond.
At which level of protein structure are interactions between the side chains (R groups) most important?
primary
secondary
tertiary
quaternary
The function of each protein is a consequence of its specific shape. What is the term used for a change in a proteinʹs three-dimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds?
hydrolysis
stabilization
denaturation
Which of the following statements about the 5ʹ end of a polynucleotide strand of DNA is correct?
The 5ʹ end has a hydroxyl group attached to the number 5 carbon of ribose.
The 5ʹ end has a phosphate group attached to the number 5 carbon of ribose.
Of the following functions, the major purpose of RNA is to
transmit genetic information to offspring.
function in the synthesis of protein.
make a copy of itself, thus ensuring genetic continuity.
act as a pattern or blueprint to form DNA.
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base and a phosphate group
a nitrogenous base and a pentose sugar
a nitrogenous base, a phosphate group, and a pentose sugar
Which of the following are nitrogenous bases of the pyrimidine type?
guanine and adenine
cytosine and uracil
thymine and guanine
Which of the following are nitrogenous bases of the purine type?
cytosine and guanine
guanine and adenine
adenine and thymine
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?
10
20
40
80
Which of the following statements best summarizes the structural differences between DNA and RNA?
RNA is a protein, whereas DNA is a nucleic acid
DNA is a protein, whereas RNA is a nucleic acid.
DNA nucleotides contain a different sugar than RNA nucleotides.
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
deoxyribose.
ribose.
adenine.
guanine.
If one strand of a DNA molecule has the sequence of bases 5ʹATTGCA3ʹ, the other complementary strand would have the sequence
5ʹTAACGT3ʹ.
3ʹTAACGT5ʹ.
5ʹUAACGU3ʹ.
5ʹUGCAAU3ʹ
What is the structural feature that allows DNA to replicate?
sugar-phosphate backbone
complementary pairing of the nitrogenous bases
disulfide bonding (bridging) of the two helixes
A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism
is more closely related to humans than to frogs.
is more closely related to frogs than to humans.
may have evolved from gibbons but not rats.
is more closely related to humans than to rats.
The element nitrogen is present in all of the following except
proteins.
nucleic acids.
amino acids.
DNA.
monosaccharides.
Which of the following is a diverse group of hydrophobic molecules?
carbohydrates
lipids
proteins
nucleic acids
Enzymes are
carbohydrates.
lipids.
proteins.
nucleic acids.
Which term includes all others in the list?
monosaccharide
disaccharide
starch
carbohydrate
polysaccharide
