Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
5′ cap - ANSWER: A modified form of guanine nucleotide added onto the 5′ end of a
pre-mRNA molecule.
A site - ANSWER: One of a ribosome's three binding sites for tRNA during
translation. The A site holds the tRNA carrying the next amino acid to be added to the
polypeptide chain. (A stands for aminoacyl tRNA.)
ABC hypothesis - ANSWER: A model of flower formation identifying three classes of
organ identity genes that direct formation of the four types of floral organs.
abiotic (ā′-bī-ot′-ik) - ANSWER: Nonliving; referring to the physical and chemical
properties of an environment.
abortion - ANSWER: The termination of a pregnancy in progress.
abscisic acid (ABA) (ab-sis′-ik) - ANSWER: A plant hormone that slows growth, often
antagonizing the actions of growth hormones. Two of its many effects are to promote
seed dormancy and facilitate drought tolerance.
absorption - ANSWER: The third stage of food processing in animals: the uptake of
small nutrient molecules by an organism's body.
absorption spectrum - ANSWER: The range of a pigment's ability to absorb various
wavelengths of light; also a graph of such a range.
abyssal zone (uh-bis′-ul) - ANSWER: The part of the ocean's benthic zone between
2,000 and 6,000 m deep.
acanthodian (ak′-an-thō′-dē-un) - ANSWER: Any of a group of ancient jawed aquatic
vertebrates from the Silurian and Devonian periods.
accessory fruit - ANSWER: A fruit, or assemblage of fruits, in which the fleshy parts
are derived largely or entirely from tissues other than the ovary.
acclimatization (uh-klī′-muh-tī -zā′-shun) - ANSWER: Physiological adjustment to a
change in an environmental factor.
,Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
acetyl CoA - ANSWER: Acetyl coenzyme A; the entry compound for the citric acid
cycle in cellular respiration, formed from a two-carbon fragment of pyruvate attached to
a coenzyme.
acetylcholine (as′-uh-til-kō′-lēn) - ANSWER: One of the most common
neurotransmitters; functions by binding to receptors and altering the permeability of the
postsynaptic membrane to specific ions, either depolarizing or hyperpolarizing the
membrane.
acid - ANSWER: A substance that increases the hydrogen ion concentration of a
solution.
acoelomate (uh-sē′-lō-māt) - ANSWER: A solid-bodied animal lacking a cavity
between the gut and outer body wall.
acquired immunodeficiency syndrome (AIDS) - ANSWER: The symptoms and signs
present during the late stages of HIV infection, defined by a specified reduction in the
number of T cells and the appearance of characteristic secondary infections.
acrosomal reaction (ak′-ruh-sōm′-ul) - ANSWER: The discharge of hydrolytic
enzymes from the acrosome, a vesicle in the tip of a sperm, when the sperm
approaches or contacts an egg.
acrosome (ak′-ruh-sōm) - ANSWER: A vesicle in the tip of a sperm containing
hydrolytic enzymes and other proteins that help the sperm reach the egg.
actin (ak′-tin) - ANSWER: A globular protein that links into chains, two of which twist
helically about each other, forming microfilaments (actin filaments) in muscle and other
kinds of cells.
action potential - ANSWER: An electrical signal that propagates (travels) along the
membrane of a neuron or other excitable cell as a nongraded (all-or-none)
depolarization.
action spectrum - ANSWER: A graph that profiles the relative effectiveness of
different wavelengths of radiation in driving a particular process.
,Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
activation energy - ANSWER: The amount of energy that reactants must absorb
before a chemical reaction will start; also called free energy of activation.
activator - ANSWER: A protein that binds to DNA and stimulates gene transcription.
In prokaryotes, activators bind in or near the promoter; in eukaryotes, activators
generally bind to control elements in enhancers.
active immunity - ANSWER: Long-lasting immunity conferred by the action of B cells
and T cells and the resulting B and T memory cells specific for a pathogen. Active
immunity can develop as a result of natural infection or immunization.
active site - ANSWER: The specific region of an enzyme that binds the substrate and
that forms the pocket in which catalysis occurs.
active transport - ANSWER: The movement of a substance across a cell membrane
against its concentration or electrochemical gradient, mediated by specific transport
proteins and requiring an expenditure of energy.
adaptation - ANSWER: Inherited characteristic of an organism that enhances its
survival and reproduction in a specific environment.
adaptive evolution - ANSWER: Evolution that results in a better match between
organisms and their environment.
adaptive immunity - ANSWER: A vertebrate-specific defense that is mediated by B
lymphocytes (B cells) and T lymphocytes (T cells) and that exhibits specificity, memory,
and self-nonself recognition; also called acquired immunity.
adaptive radiation - ANSWER: Period of evolutionary change in which groups of
organisms form many new species whose adaptations allow them to fill different
ecological roles in their communities.
addition rule - ANSWER: A rule of probability stating that the probability of any one of
two or more mutually exclusive events occurring can be determined by adding their
individual probabilities.
adenylyl cyclase (uh-den′-uh-lil) - ANSWER: An enzyme that converts ATP to cyclic
AMP in response to an extracellular signal.
, Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
adhesion - ANSWER: The clinging of one substance to another, such as water to
plant cell walls by means of hydrogen bonds.
adipose tissue - ANSWER: A connective tissue that insulates the body and serves as
a fuel reserve; contains fat-storing cells called adipose cells.
adrenal gland (uh-drē′-nul) - ANSWER: One of two endocrine glands located adjacent
to the kidneys in mammals. Endocrine cells in the outer portion (cortex) respond to
adrenocorticotropic hormone (ACTH) by secreting steroid hormones that help maintain
homeostasis during long-term stress. Neurosecretory cells in the central portion
(medulla) secrete epinephrine and norepinephrine in response to nerve signals
triggered by short-term stress.
aerobic respiration - ANSWER: A catabolic pathway for organic molecules, using
oxygen (O2)(O2) as the final electron acceptor in an electron transport chain and
ultimately producing ATP. This is the most efficient catabolic pathway and is carried out
in most eukaryotic cells and many prokaryotic organisms.
age structure - ANSWER: The relative number of individuals of each age in a
population.
aggregate fruit - ANSWER: A fruit derived from a single flower that has more than
one carpel.
AIDS (acquired immunodeficiency syndrome) - ANSWER: The symptoms and signs
present during the late stages of HIV infection, defined by a specified reduction in the
number of T cells and the appearance of characteristic secondary infections.
alcohol fermentation - ANSWER: Glycolysis followed by the reduction of pyruvate to
ethyl alcohol, regenerating NAD+NAD+ and releasing carbon dioxide.
alga (plural, algae) - ANSWER: A general term for any species of photosynthetic
protist, including both unicellular and multicellular forms. Algal species are included in
three eukaryote supergroups (Excavata, SAR, and Archaeplastida).
alimentary canal (al′-uh-men′-tuh-rē) - ANSWER: A complete digestive tract,
consisting of a tube running between a mouth and an anus.
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
5′ cap - ANSWER: A modified form of guanine nucleotide added onto the 5′ end of a
pre-mRNA molecule.
A site - ANSWER: One of a ribosome's three binding sites for tRNA during
translation. The A site holds the tRNA carrying the next amino acid to be added to the
polypeptide chain. (A stands for aminoacyl tRNA.)
ABC hypothesis - ANSWER: A model of flower formation identifying three classes of
organ identity genes that direct formation of the four types of floral organs.
abiotic (ā′-bī-ot′-ik) - ANSWER: Nonliving; referring to the physical and chemical
properties of an environment.
abortion - ANSWER: The termination of a pregnancy in progress.
abscisic acid (ABA) (ab-sis′-ik) - ANSWER: A plant hormone that slows growth, often
antagonizing the actions of growth hormones. Two of its many effects are to promote
seed dormancy and facilitate drought tolerance.
absorption - ANSWER: The third stage of food processing in animals: the uptake of
small nutrient molecules by an organism's body.
absorption spectrum - ANSWER: The range of a pigment's ability to absorb various
wavelengths of light; also a graph of such a range.
abyssal zone (uh-bis′-ul) - ANSWER: The part of the ocean's benthic zone between
2,000 and 6,000 m deep.
acanthodian (ak′-an-thō′-dē-un) - ANSWER: Any of a group of ancient jawed aquatic
vertebrates from the Silurian and Devonian periods.
accessory fruit - ANSWER: A fruit, or assemblage of fruits, in which the fleshy parts
are derived largely or entirely from tissues other than the ovary.
acclimatization (uh-klī′-muh-tī -zā′-shun) - ANSWER: Physiological adjustment to a
change in an environmental factor.
,Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
acetyl CoA - ANSWER: Acetyl coenzyme A; the entry compound for the citric acid
cycle in cellular respiration, formed from a two-carbon fragment of pyruvate attached to
a coenzyme.
acetylcholine (as′-uh-til-kō′-lēn) - ANSWER: One of the most common
neurotransmitters; functions by binding to receptors and altering the permeability of the
postsynaptic membrane to specific ions, either depolarizing or hyperpolarizing the
membrane.
acid - ANSWER: A substance that increases the hydrogen ion concentration of a
solution.
acoelomate (uh-sē′-lō-māt) - ANSWER: A solid-bodied animal lacking a cavity
between the gut and outer body wall.
acquired immunodeficiency syndrome (AIDS) - ANSWER: The symptoms and signs
present during the late stages of HIV infection, defined by a specified reduction in the
number of T cells and the appearance of characteristic secondary infections.
acrosomal reaction (ak′-ruh-sōm′-ul) - ANSWER: The discharge of hydrolytic
enzymes from the acrosome, a vesicle in the tip of a sperm, when the sperm
approaches or contacts an egg.
acrosome (ak′-ruh-sōm) - ANSWER: A vesicle in the tip of a sperm containing
hydrolytic enzymes and other proteins that help the sperm reach the egg.
actin (ak′-tin) - ANSWER: A globular protein that links into chains, two of which twist
helically about each other, forming microfilaments (actin filaments) in muscle and other
kinds of cells.
action potential - ANSWER: An electrical signal that propagates (travels) along the
membrane of a neuron or other excitable cell as a nongraded (all-or-none)
depolarization.
action spectrum - ANSWER: A graph that profiles the relative effectiveness of
different wavelengths of radiation in driving a particular process.
,Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
activation energy - ANSWER: The amount of energy that reactants must absorb
before a chemical reaction will start; also called free energy of activation.
activator - ANSWER: A protein that binds to DNA and stimulates gene transcription.
In prokaryotes, activators bind in or near the promoter; in eukaryotes, activators
generally bind to control elements in enhancers.
active immunity - ANSWER: Long-lasting immunity conferred by the action of B cells
and T cells and the resulting B and T memory cells specific for a pathogen. Active
immunity can develop as a result of natural infection or immunization.
active site - ANSWER: The specific region of an enzyme that binds the substrate and
that forms the pocket in which catalysis occurs.
active transport - ANSWER: The movement of a substance across a cell membrane
against its concentration or electrochemical gradient, mediated by specific transport
proteins and requiring an expenditure of energy.
adaptation - ANSWER: Inherited characteristic of an organism that enhances its
survival and reproduction in a specific environment.
adaptive evolution - ANSWER: Evolution that results in a better match between
organisms and their environment.
adaptive immunity - ANSWER: A vertebrate-specific defense that is mediated by B
lymphocytes (B cells) and T lymphocytes (T cells) and that exhibits specificity, memory,
and self-nonself recognition; also called acquired immunity.
adaptive radiation - ANSWER: Period of evolutionary change in which groups of
organisms form many new species whose adaptations allow them to fill different
ecological roles in their communities.
addition rule - ANSWER: A rule of probability stating that the probability of any one of
two or more mutually exclusive events occurring can be determined by adding their
individual probabilities.
adenylyl cyclase (uh-den′-uh-lil) - ANSWER: An enzyme that converts ATP to cyclic
AMP in response to an extracellular signal.
, Test Bank - Campbell Biology, 11th Edition
(Urry) : Campbell Biology 11th Edition Urry
Test Bank Exam with COMPLETE QUESTIONS
AND ANSWERS
adhesion - ANSWER: The clinging of one substance to another, such as water to
plant cell walls by means of hydrogen bonds.
adipose tissue - ANSWER: A connective tissue that insulates the body and serves as
a fuel reserve; contains fat-storing cells called adipose cells.
adrenal gland (uh-drē′-nul) - ANSWER: One of two endocrine glands located adjacent
to the kidneys in mammals. Endocrine cells in the outer portion (cortex) respond to
adrenocorticotropic hormone (ACTH) by secreting steroid hormones that help maintain
homeostasis during long-term stress. Neurosecretory cells in the central portion
(medulla) secrete epinephrine and norepinephrine in response to nerve signals
triggered by short-term stress.
aerobic respiration - ANSWER: A catabolic pathway for organic molecules, using
oxygen (O2)(O2) as the final electron acceptor in an electron transport chain and
ultimately producing ATP. This is the most efficient catabolic pathway and is carried out
in most eukaryotic cells and many prokaryotic organisms.
age structure - ANSWER: The relative number of individuals of each age in a
population.
aggregate fruit - ANSWER: A fruit derived from a single flower that has more than
one carpel.
AIDS (acquired immunodeficiency syndrome) - ANSWER: The symptoms and signs
present during the late stages of HIV infection, defined by a specified reduction in the
number of T cells and the appearance of characteristic secondary infections.
alcohol fermentation - ANSWER: Glycolysis followed by the reduction of pyruvate to
ethyl alcohol, regenerating NAD+NAD+ and releasing carbon dioxide.
alga (plural, algae) - ANSWER: A general term for any species of photosynthetic
protist, including both unicellular and multicellular forms. Algal species are included in
three eukaryote supergroups (Excavata, SAR, and Archaeplastida).
alimentary canal (al′-uh-men′-tuh-rē) - ANSWER: A complete digestive tract,
consisting of a tube running between a mouth and an anus.
