Animal cells that are present only for a brief developmental phase will, following completion of that phase, undergo
A) diapause.
B) apoptosis
C) meiosis.
D) oxidative phosphorylation.

Answer: B

The nucleus and most of the organelles in a neuron are located in the
A) dendritic region.
B) axon hillock.
C) axon.
D) cell body.

Answer: D

The point of connection between two communicating neurons is called
A) the axon hillock.
B) the dendrite.
C) the synapse.
D) the cell body.

Answer: C

ATP hydrolysis directly powers the movement of
A) K+ out of cells.
B) Na+ out of cells.
C) Na+ into cells.
D) Ca++ into cells.

Answer: B

Why are action potentials usually conducted in one direction?
A) The nodes of Ranvier conduct potentials in one direction.
B) The brief refractory period prevents reopening of voltage-gated Na+ channels.
C) The axon hillock has a higher membrane potential than the terminals of the axon.
D) Ions can flow along the axon in only one direction.

Answer: B

The membrane's permeability to sodium ions is at its maximum at label
A) A.
B) B.
C) C.
D) D.

Answer: B

Myelinated neurons are especially abundant in the
A) gray matter of the brain and the white matter of the spinal cord.
B) white matter of the brain and the gray matter of the spinal cord.
C) gray matter of the brain and the gray matter of the spinal cord.
D) white matter in the brain and the white matter in the spinal cord.

Answer: D

Exercise and emergency reactions include
A) increased activity in all parts of the peripheral nervous system.
B) increased activity in the sympathetic, and decreased activity in the parasympathetic branches.
C) decreased activity in the sympathetic, and increased activity in the parasympathetic branches.
D) increased activity in the enteric nervous system.

Answer: B

Bottlenose dolphins breathe air but can sleep in the ocean because
A) they alternate which half of their brains is asleep and which half is awake.
B) they sleep for only 30 minutes at a time, which is the maximum interval they can cease breathing.
C) they fill their swim bladder with air to keep their blowholes above the surface of the water while they sleep.
D) they move to shallow water to sleep, so they do not need to swim to keep their blowholes above the surface of the water.

Answer: A

Which of the following structures are correctly paired?
A) forebrain and medulla oblongata
B) forebrain and cerebellum
C) midbrain and cerebrum
D) hindbrain and cerebellum

Answer: D

When Phineas Gage had a metal rod driven into his frontal lobe, or when someone had a frontal lobotomy, they would
A) lose the ability to reason.
B) lose all short-term memory.
C) have greatly altered emotional responses.
D) lose all long-term memory.

Answer: C

The correct sequence of sensory processing is
A) sensory adaptation → stimulus reception → sensory transduction → sensory perception.
B) stimulus reception → sensory transduction → sensory perception → sensory adaptation.
C) sensory perception → stimulus reception → sensory transduction → sensory adaptation.
D) sensory perception → sensory transduction → stimulus reception → sensory adaptation.

Answer: B

Which of the following sensory receptors is correctly paired with its category?
A) hair cell - mechanoreceptor
B) muscle spindle - electromagnetic receptor
C) taste receptor - mechanoreceptor
D) rod - chemoreceptor

Answer: A

Partial or complete loss of hearing (deafness) can be caused by damage to the ________.
I) axons of the neurons associated with each hair cell that carry information to the brain
II) hair cells (the sensory receptors) in the cochlea
III) tympanic membrane, or eardrum

A) only II
B) only III
C) I, II, and III
D) only I and II

Answer: C

Umami perception would be stimulated by ________.
A) aged cheese
B) saltwater
C) lemonade
D) chocolate milk

Answer: A

The "motor unit" in vertebrate skeletal muscle refers to ________.
A) one sarcomere and all of its actin and myosin filaments
B) one myofibril and all of its sarcomeres
C) one actin binding site and its myosin partner
D) one motor neuron and all of the muscle fibers on which it has synapses

Answer: D

During fertilization, the acrosomal contents
A) block polyspermy.
B) help propel more sperm toward the egg.
C) digest the protective jelly coat on the surface of the egg.
D) nourish the mitochondria of the sperm.

Answer: C

In a newly fertilized egg, the vitelline layer
A) opens the egg's nuclear membrane to allow haploid sperm DNA to enter.
B) lifts away from the egg and hardens to form a fertilization envelope.
C) secretes hormones that enhance steroidogenesis by the ovary.
D) reduces the loss of water from the egg and prevents desiccation.

Answer: B

Among these choices, the largest cell involved in frog reproduction is
A) the spermatozoon.
B) the egg.
C) a blastomere in the vegetal pole.
D) a blastomere in the animal pole.

Answer: B

At the moment of sperm penetration, human eggs
A) have used flagellar propulsion to move from the ovary to the oviduct.
B) are still surrounded by follicular cells.
C) are still located within the ovary.
D) have a paper-thin cell of calcium carbonate that prevents desiccation.

Answer: B

Which of the following correctly displays the sequence of developmental milestones?
A) blastula → gastrula → cleavage
B) cleavage → gastrula → blastula
C) cleavage → blastula → gastrula
D) gastrula → blastula → cleavage

Answer: C

Cells move to new positions as an embryo establishes its three germ tissue layers during
A) determination.
B) cleavage.
C) gastrulation.
D) induction.

Answer: C

The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is
A) endoderm → ectoderm → mesoderm.
B) mesoderm → endoderm → ectoderm.
C) ectoderm → mesoderm → endoderm.
D) ectoderm → endoderm → mesoderm.

Answer: C

In all vertebrate animals, development requires
A) a large supply of yolk.
B) an aqueous environment.
C) extraembryonic membranes.
D) an amnion.

Answer: B

From earliest to latest, the overall sequence of early development proceeds in which of the following sequences?
A) gastrulation → organogenesis → cleavage
B) ovulation → gastrulation → fertilization
C) cleavage → gastrulation → organogenesis
D) gastrulation → blastulation → neurulation

Answer: C

Changes in the shape of a cell usually involve a reorganization of the
A) nucleus.
B) cytoskeleton.
C) extracellular matrix.
D) transport proteins.

Answer: B

The embryonic precursor to the human spinal cord is the
A) notochord.
B) neural tube.
C) mesoderm.
D) archenteron.

Answer: B

During human fetal development, webbing between fingers and toes is eliminated by the process of ________.
A) oxidative phosphorylation
B) regeneration
C) apoptosis
D) re-differentiation

Answer: C

What structural adaptation in chickens allows them to lay their eggs in arid environments rather than in water?
A) development of the brain from ectoderm
B) yolk
C) amnion
D) gastrulation

Answer: C

Which of the following best describes a model organism?
A) It has been chosen for study by early biologists.
B) It is small, inexpensive to raise, and lives a long time.
C) It is well studied, it is easy to grow, and results are widely applicable.
D) It is often pictured in textbooks and easy for students to imagine.

Answer: C

Which of the following model systems is an adult organism that has fewer than 1,000 cells?
A) chickens, Gallus domesticus
B) African clawed frogs, Xenopus laevis
C) nematodes, Caenorhabditis elegans
D) fruit flies, Drosophila melanogaster

Answer: C

The arrangement of organs and tissues in their characteristic places in 3-D space defines
A) pattern formation.
B) induction.
C) differentiation.
D) determination.

Answer: A

Most of the neurons in the human brain are
A) sensory neurons.
B) motor neurons.
C) interneurons.
D) auditory neurons.

Answer: C

The operation of the sodium-potassium "pump" moves
A) sodium and potassium ions into the cell.
B) sodium and potassium ions out of the cell.
C) sodium ions into the cell and potassium ions out of the cell.
D) sodium ions out of the cell and potassium ions into the cell.

Answer: D

Which of the following statements about action potentials is correct?
A) Action potentials for a given neuron vary in magnitude.
B) Movement of ions during the action potential occurs mostly through the sodium pump.
C) Action potentials for a given neuron vary in duration.
D) Action potentials are propagated down the length of the axon.

Answer: D

In a simple synapse, neurotransmitter chemicals are released by
A) the dendritic membrane.
B) the presynaptic membrane.
C) axon hillocks.
D) cell bodies.

Answer: B

Why are action potentials usually conducted in one direction?
A) The nodes of Ranvier conduct potentials in one direction.
B) The brief refractory period prevents reopening of voltage-gated Na+ channels.
C) The axon hillock has a higher membrane potential than the terminals of the axon.
D) Ions can flow along the axon in only one direction.

Answer: B

Action potentials move along axons
A) more slowly in axons of large than in small diameter.
B) by the direct action of acetylcholine on the axonal membrane.
C) by activating the sodium-potassium "pump" at each point along the axonal membrane.
D) more rapidly in myelinated than in non-myelinated axons.

Answer: D

The neuronal membrane is at its resting potential at label
A) A.
B) B.
C) D.
D) E.

Answer: D

The minimum graded depolarization needed to operate the voltage-gated sodium and potassium channels is indicated by the label
A) A.
B) B.
C) D.
D) E.

Answer: A

The cell is not hyperpolarized; however, repolarization is in progress, as the sodium channels are closing or closed, and many potassium channels have opened at label
A) B.
B) C.
C) D.
D) E.

Answer: B

For a neuron with an initial membrane potential at -70 mV, an increase in the movement of potassium ions out of that neuron's cytoplasm would result in
A) the depolarization of the neuron.
B) the hyperpolarization of the neuron.
C) the replacement of potassium ions with sodium ions.
D) the replacement of potassium ions with calcium ions.

Answer: B

Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?
A) Voltage-gated calcium channels in the membrane open.
B) Synaptic vesicles fuse with the membrane.
C) The postsynaptic cell produces an action potential.
D) Ligand-gated channels open, allowing neurotransmitters to enter the synaptic cleft.

Answer: A

Neurotransmitters are released from axon terminals via
A) osmosis.
B) active transport.
C) diffusion.
D) exocytosis.

Answer: D

Choose the correct match of glial cell type and function.
A) astrocytesmetabolize neurotransmitters and modulate synaptic effectiveness
B) oligodendrocytesproduce the myelin sheaths of myelinated neurons in the peripheral nervous system
C) microgliaproduce the myelin sheaths of myelinated neurons in the central nervous system
D) radial gliathe source of immunoprotection against pathogens.

Answer: A

Myelinated neurons are especially abundant in the
A) gray matter of the brain and the white matter of the spinal cord.
B) white matter of the brain and the gray matter of the spinal cord.
C) gray matter of the brain and the gray matter of the spinal cord.
D) white matter in the brain and the white matter in the spinal cord.

Answer: D

The myelin sheath plays an important role in neuron structure and function. However, when the myelin sheath is missing or not fully intact, there are consequences. There are many conditions that cause demyelination of neurons, some are autoimmune disorders, such as multiple sclerosis, and others are hereditary. The symptoms of these conditions vary, but often include speech impairment and difficulty coordinating movement. Which of the following correctly connects the symptoms of demyelination with the process of nerve impulse transmission?
A) Demyelination prevents the formation of an action potential in sensory neurons that transmit signals from the environment to the central nervous system.
B) Demyelination slows nerve impulse transmission.
C) Demyelination prevents the uptake of neurotransmitters needed to propagate a message to the next neuron.
D) Demyelination targets the central nervous system.

Answer: B

Increased activity in the sympathetic nervous system leads to
A) decreased heart rate.
B) increased secretion by the pancreas.
C) relaxation of the airways in the lungs.
D) increased contraction of the stomach.

Answer: C

The central nervous system is lacking in animals that have
A) a complete gut.
B) bilateral symmetry.
C) radial symmetry.
D) a closed circulatory system.

Answer: C

In a cephalized invertebrate, the system that transmits "efferent" impulses from the anterior ganglion to distal segments is the
A) central nervous system.
B) peripheral nervous system.
C) autonomic nervous system.
D) parasympathetic nervous system.

Answer: B

Which of the following structures or regions is correctly paired with its function?
A) limbic systemmotor control of speech
B) medulla oblongataemotional memory
C) cerebellumhomeostatic control
D) corpus callosumcommunication between the left and right cerebral cortices

Answer: D

Calculation, contemplation, and cognition are human activities associated with increased activity in the
A) pituitary gland.
B) hypothalamus.
C) cerebrum.
D) cerebellum.

Answer: C

The unconscious control of respiration and circulation are associated with the
A) thalamus.
B) cerebellum.
C) medulla oblongata.
D) corpus callosum.

Answer: C

Central coordination of vertebrate biological rhythms in physiology and behavior reside in the
A) pituitary gland.
B) hypothalamus.
C) cerebrum.
D) cerebellum.

Answer: B

Wakefulness is regulated by the reticular formation, which is present in the
A) basal nuclei.
B) cerebral cortex.
C) brainstem.
D) limbic system.

Answer: C

Which of the following shows a brain structure correctly paired with one of its primary functions?
A) frontal lobedecision making
B) occipital lobecontrol of skeletal muscles
C) temporal lobevisual processing
D) cerebellumlanguage comprehension

Answer: A

Bipolar disorder differs from schizophrenia in that
A) schizophrenia typically involves hallucinations.
B) schizophrenia typically involves manic and depressive states.
C) schizophrenia typically involves decreased dopamine.
D) bipolar disorder involves both genes and environment.

Answer: A

One of the complications of Alzheimer's disease is an interference with learning and memory. This disease would most likely involve ________.
A) changes in the concentration of ions in the extracellular fluid surrounding neurons
B) molecular and structural changes at synapses
C) changes in myelination of axons
D) structural changes to ion channels in axons

Answer: B

A behavioral physiologist is studying the homeostatic control of blood pH. In atrial, a lizard runs on a treadmill for a set amount of time and the blood pH is measured. The blood pH drops as carbon dioxide is released into the bloodstream.Which component of the homeostatic feedback system is responsible for deciding if the blood pH is far enough from normal that a response is necessary?
A) assimilator
B) sensor
C) effector
D) integrator

Answer: D

Immediately after putting on a shirt, your skin might feel itchy. However, this perception soon fades due to
A) sensory adaptation.
B) accommodation.
C) the increase of transduction.
D) reduced motor unit recruitment.

Answer: A

Hair cells in the vertebrate ear are responsible for transducing sound pressure waves. Ion channels in the hair cell membrane open when ________.
A) a chemical ligand binds to the ion channel
B) light is absorbed by a molecule in the membrane
C) the membrane is distorted mechanically
D) the cell membrane reaches a threshold voltage

Answer: C

Sensory transduction of light in the vertebrate retina is accomplished by
A) ganglion cells.
B) amacrine cells.
C) bipolar cells.
D) rods and cones.

Answer: D

Which sensory distinction is not encoded by a difference in neuron identity?
A) white and red
B) red and green
C) loud and faint
D) salty and sweet

Answer: C

The contraction of skeletal muscles is based on
A) myosin cross-bridges binding to actin and then flexing.
B) myosin filaments coiling up to become shorter.
C) actin and myosin filaments both coiling up to become shorter.
D) actin cross-bridges binding to myosin and then flexing.

Answer: A

A skeletal muscle deprived of adequate ATP supplies will
A) immediately relax.
B) release all actin-myosin bonds.
C) enter a state where actin and myosin are unable to separate.
D) fire many more action potentials than usual and enter a state of "rigor."

Answer: C

Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber?

1. Tropomyosin shifts and unblocks the cross-bridge binding sites.
2. Calcium is released and binds to the troponin complex.
3. Transverse tubules depolarize the sarcoplasmic reticulum.
4. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP.
5. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane.

A) 1 → 2 → 3 → 4 → 5
B) 2 → 1 → 3 → 5 → 4
C) 2 → 3 → 4 → 1 → 5
D) 5 → 3 → 2 → 1 → 4

Answer: D

What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?
A) Muscle contractions could still occur, but relaxation of the muscle would be impaired.
B) Muscle contractions would be prevented, causing paralysis.
C) Action potentials would be continuously generated, causing convulsive muscle contractions.
D) Action potentials would be continuously generated, causing convulsive muscle contractions; muscle contractions would then be prevented, causing paralysis.

Answer: B

An endoskeleton is the primary body support for the
A) annelids, including earthworms.
B) insects, including beetles.
C) cartilaginous fishes, including sharks.
D) bivalves, including clams.

Answer: C

Chitin is a major component of
A) the skeleton of mammals.
B) the hydrostatic skeletons of earthworms.
C) the exoskeleton of insects.
D) the body hairs of mammals.

Answer: C

What type of signal is long-lasting and works at night?
A) olfactory
B) visual
C) auditory
D) tactile

Answer: A

A stickleback fish will attack a fish model as long as the model has red coloring. What animal behavior idea is manifested by this observation?
A) sign stimulus
B) cognition
C) imprinting
D) classical conditioning

Answer: A

Which of the following experiments best addresses the hypothesis that moths stop flying in response to high-intensity bat sounds?
A) Isolate and characterize the neurons that control flight muscle.
B) Put bats and moths in an enclosure and make detailed observations of predator-prey interactions.
C) Observe responses of moths to bats in nature.
D) Play prerecorded high-intensity bat sounds to flying moths.

Answer: D

The proximate causes of behavior are interactions with the environment, but behavior is ultimately shaped by
A) hormones.
B) evolution.
C) sexuality.
D) pheromones.

Answer: B

Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question.

A. operant conditioning
B. agonistic behavior
C. innate behavior
D. imprinting
E. altruistic behavior

Through trial and error, a rat learns to run a maze without mistakes to receive a food reward.
A) A
B) B
C) C
D) D

Answer: A

Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question.

A. operant conditioning
B. agonistic behavior
C. innate behavior
D. imprinting
E. altruistic behavior

A human baby performs a sucking behavior perfectly when it is put in the presence of the nipple of its mother's breast.
A) A
B) B
C) C
D) D

Answer: C

Listed below are several examples of types of animal behavior. Match the letter of the correct term (A-E) to each example in the following question.

A. operant conditioning
B. agonistic behavior
C. innate behavior
D. imprinting
E. altruistic behavior

Upon observing a golden eagle flying overhead, a sentry prairie dog gives a warning call to other foraging members of the prairie dog community.
A) B
B) C
C) D
D) E

Answer: D

Every morning at the same time, John went into the den to feed his new tropical fish. After a few weeks, he noticed that the fish swam to the top of the tank when he entered the room. This is an example of
A) cognition.
B) imprinting.
C) classical conditioning.
D) operant conditioning.

Answer: C

One way to understand how early environment influences differing behaviors in similar species is through the "cross-fostering" experimental technique. Suppose that the curly-whiskered mud rat differs from the bald mud rat in several ways, including being much more aggressive. How would you set up a cross-fostering experiment to determine if environment plays a role in the curly-whiskered mud rat's aggression?
A) You would cross curly-whiskered mud rats and bald mud rats and hand-rear the offspring to see if any grew up to be aggressive.
B) You would place newborn curly-whiskered mud rats with bald mud rat parents, place newborn bald mud rats with curly-whiskered mud rat parents, and let some mud rats of both species be raised by their own species. Then you would compare the outcomes.
C) You would remove the offspring of curly-whiskered mud rats and bald mud rats from their parents, raise them in the same environment, and then compare the outcomes.
D) You would see if curly-whiskered mud rats bred true for aggression.

Answer: B

Which of the following is true of innate behaviors?
A) Their expression is only weakly influenced by genes.
B) They occur with or without environmental stimuli.
C) They are limited to invertebrate animals.
D) They are expressed in most individuals in a population.

Answer: D

Although many chimpanzees live in environments containing oil palm nuts, members of only a few populations use stones to crack open the nuts. The likely explanation is that
A) the behavioral difference is caused by genetic differences between populations.
B) members of different populations have different nutritional requirements.
C) the cultural tradition of using stones to crack nuts has arisen in only some populations.
D) members of different populations differ in learning ability.

Answer: C

Female spotted sandpipers aggressively court males and, after mating, leave the clutch of young for the male to incubate. This sequence may be repeated several times with different males until no available males remain, forcing the female to incubate her last clutch. Which of the following terms best describes this behavior?
A) monogamy
B) polygyny
C) polyandry
D) promiscuity

Answer: C

Feeding behavior with a high energy intake-to-expenditure ratio is called
A) optimal foraging.
B) autotrophy.
C) heterotrophy.
D) search scavenging.

Answer: A

Which of the following is most likely associated with the evolution of mating systems?
A) population density.
B) territoriality.
C) certainty of paternity.
D) sexual dimorphism.

Answer: D

Which of the following best describes "game theory" as it applies to animal behavior?
A) The fitness of a particular behavior is influenced by other behavioral phenotypes in a population.
B) The total of all of the behavioral displays, both male and female, is related to courtship.
C) An individual in a population changes a behavioral phenotype to gain a competitive advantage.
D) The play behavior performed by juveniles allows them to perfect adult behaviors that are needed for survival, such as hunting, courtship, and so on.

Answer: A

The color of throats of males in a population of side-blotched lizards is determined by
A) the success of the mating behavior of each of the throat color phenotypes.
B) ambient temperature: blue = cold; orange = normal; yellow = hot.
C) stage of development/maturity.
D) their receptiveness to mate.

Answer: A

Animals that help other animals of the same species
A) have excess energy reserves.
B) are bigger and stronger than the other animals.
C) are usually related to the other animals.
D) are always male.

Answer: C

(DIAGRAM) In the figure above, which of the following conclusions is most logical based on the data?
A) Females produce more eggs more quickly when exposed to breeding males.
B) Females produce eggs more quickly when exposed to many males than females paired with a male.
C) After four weeks together, females with males produce mature follicles to the same extent as females without males.
D) All non-isolated females do just as well as isolated females.

Answer: A