Question 1

A person able to hear only high-frequency sounds would probably have which of the following structural problems in the ear?

Accepted Answer

A) The tympanum is damaged because of chronic ear infections. 
B) The basilar membrane is stiffened along its entire length. 
C) The ear ossicles are abnormally thickened. 
D) All of the above problems could result in inability to detect low-frequency sound. 
A) The tympanum is damaged because of chronic ear infections. 
B) The basilar membrane is stiffened along its entire length. 
C) The ear ossicles are abnormally thickened. 
D) All of the above problems could result in inability to detect low-frequency sound. B

Question 2

When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ),a series of events occurs that leads to muscle contraction.Which of the following events will occur last (i.e. ,after all of the others)?

Accepted Answer

A) ACh release 
B) action potential propagation down the T-tubules 
C) conformational change in troponin 
D) depolarization of the muscle cell 
E) release of Ca²⁺ from the sarcoplasmic reticulum 
A) ACh release 
B) action potential propagation down the T-tubules 
C) conformational change in troponin 
D) depolarization of the muscle cell 
E) release of Ca²⁺ from the sarcoplasmic reticulum C

Question 3

Two students studying physiology taste a known "bitter" substance,and both report sensing bitterness.They then sample another substance.Student A reports sensing both a bitter taste and a salty taste,but student B reports only a salty taste.What is the most logical explanation?

Accepted Answer

A) Student A had an allergic reaction to the food,causing him to perceive the food as being bitter. 
B) Student A has normal "bitter" taste buds;student B has defective "bitter" taste buds that result in lower sensitivity to bitterness. 
C) Student A has a protein receptor capable of detecting a bitter molecule found in that substance,whereas student B lacks that particular protein receptor. 
D) Student A has normal saliva,whereas student B's saliva is more alkaline than normal. 
A) Student A had an allergic reaction to the food,causing him to perceive the food as being bitter. 
B) Student A has normal "bitter" taste buds;student B has defective "bitter" taste buds that result in lower sensitivity to bitterness. 
C) Student A has a protein receptor capable of detecting a bitter molecule found in that substance,whereas student B lacks that particular protein receptor. 
D) Student A has normal saliva,whereas student B's saliva is more alkaline than normal. C

Question 4

Training for long-distance running causes a significant increase in _____.

Accepted Answer

A) the cross-sectional area of slow-twitch muscle fibers (cells) 
B) the number of myofibrils per muscle fiber (cell),increasing cell size 
C) the number of slow-twitch muscle fibers (cells) 
D) both the cross-sectional area of slow-twitch muscle fibers (cells)and the number of myofibrils per muscle fiber (cell),increasing cell size 
E) the cross-sectional area of slow-twitch muscle fibers (cells);the number of myofibrils per muscle fiber (cell),increasing cell size;and the number of slow-twitch muscle fibers (cells) 
A) the cross-sectional area of slow-twitch muscle fibers (cells) 
B) the number of myofibrils per muscle fiber (cell),increasing cell size 
C) the number of slow-twitch muscle fibers (cells) 
D) both the cross-sectional area of slow-twitch muscle fibers (cells)and the number of myofibrils per muscle fiber (cell),increasing cell size 
E) the cross-sectional area of slow-twitch muscle fibers (cells);the number of myofibrils per muscle fiber (cell),increasing cell size;and the number of slow-twitch muscle fibers (cells)

Question 5

What is the function of the cochlea?

Accepted Answer

A) to amplify the sound vibrations 
B) to collect sound pressure waves 
C) to detect the frequency of sounds 
D) to amplify the sound vibrations and collect sound pressure waves 
E) to amplify the sound vibrations,collect sound pressure waves,and detect the frequency of sounds 
A) to amplify the sound vibrations 
B) to collect sound pressure waves 
C) to detect the frequency of sounds 
D) to amplify the sound vibrations and collect sound pressure waves 
E) to amplify the sound vibrations,collect sound pressure waves,and detect the frequency of sounds

Question 6

Researchers surgically fuse two of the three ossicles in the inner ear of a mouse,effectively leaving two functional,linked ossicles in place of three.When the mouse's hearing is tested,what outcome would be expected?

Accepted Answer

A) The mouse would be more sensitive to sound,but only in the low-frequency range. 
B) The mouse would be more sensitive to sound,but only in the high-frequency range. 
C) The mouse would be more sensitive to sound in general. 
D) The mouse would be less sensitive to sound in general. 
A) The mouse would be more sensitive to sound,but only in the low-frequency range. 
B) The mouse would be more sensitive to sound,but only in the high-frequency range. 
C) The mouse would be more sensitive to sound in general. 
D) The mouse would be less sensitive to sound in general.

Question 7

Hair cells in the vertebrate ear are responsible for transducing sound pressure waves.Ion channels in the hair cell membrane open when _____.

Accepted Answer

A) a chemical ligand binds to the ion channel 
B) light is absorbed by a molecule in the membrane 
C) the cell membrane reaches a threshold voltage 
D) the membrane is distorted mechanically 
A) a chemical ligand binds to the ion channel 
B) light is absorbed by a molecule in the membrane 
C) the cell membrane reaches a threshold voltage 
D) the membrane is distorted mechanically

Question 8

When a neurobiologist is interested in determining if an animal can see in color what structures are they looking for in the eye?

Accepted Answer

A) opsins 
B) electroreceptors 
C) pupil 
D) lens 
A) opsins 
B) electroreceptors 
C) pupil 
D) lens

Question 9

When a doctor tests your patellar reflex by tapping the tendon on the front of your knee,your lower leg comes forward.Which muscle relaxes in this reflex?

Accepted Answer

A) hamstring (located in the back of your thigh) 
B) quadriceps (located in the front of your thigh) 
A) hamstring (located in the back of your thigh) 
B) quadriceps (located in the front of your thigh)

Question 10

What would be the effect on muscle contraction if troponin were experimentally altered to no longer interact with tropomyosin,so the complex could no longer bind to actin?

Accepted Answer

A) Muscle contraction could no longer occur. 
B) Muscles could not relax after contraction. 
C) Muscle contraction would be weakened but would still occur as long as tropomyosin is functional. 
D) ATP could not be hydrolyzed by enzymes in the muscle. 
A) Muscle contraction could no longer occur. 
B) Muscles could not relax after contraction. 
C) Muscle contraction would be weakened but would still occur as long as tropomyosin is functional. 
D) ATP could not be hydrolyzed by enzymes in the muscle.

Question 11

Mammals have a family of 500 and 1000 genes that encode receptor proteins on the surface of odor-receptor neurons.If all mammals have these genes,why do some mammals have a better sense of smell than others do?

Accepted Answer

A) Some of the genes actively transcribing receptor proteins in some species are completely absent in other species. 
B) Some of the genes may have been mutated and rendered inactive in some species but not in others. 
C) Some species,particularly humans,rely much less on odor detection for survival;thus,the genes have mutated to encode proteins that aid in other senses,such as sight. 
D) Some species of mammals have a larger set of "basic odors" than other species. 
A) Some of the genes actively transcribing receptor proteins in some species are completely absent in other species. 
B) Some of the genes may have been mutated and rendered inactive in some species but not in others. 
C) Some species,particularly humans,rely much less on odor detection for survival;thus,the genes have mutated to encode proteins that aid in other senses,such as sight. 
D) Some species of mammals have a larger set of "basic odors" than other species.

Question 12

Use the following information when answering the corresponding question(s).
"Marine cone snails from the genus Conus are estimated to consist of up to 700 species.These predatory molluscs have devised an efficient venom apparatus that allows them to successfully capture polychaete worms,other molluscs or in some cases fish as their primary food sources.… conotoxins from Australian species of Conus … have the capacity to inhibit specifically the nicotinic acetylcholine receptors in higher animals." (B.G.Livett,K.R.Gayler,and Z.Khalil.2004.Drugs from the sea: Conopeptides as potential therapeutics.Current Medicinal Chemistry 11:1715-23. )
-Refer to the paragraph on the venom of marine core snails.This particular conotoxin inhibits acetylcholine receptors that are located _____.

Accepted Answer

A) along the motor neuron axon 
B) on motor neuron dendrites 
C) on the presynaptic membrane of the neuromuscular junction 
D) on the postsynaptic membrane,on the muscle cell 
A) along the motor neuron axon 
B) on motor neuron dendrites 
C) on the presynaptic membrane of the neuromuscular junction 
D) on the postsynaptic membrane,on the muscle cell

Question 13

The amount of depolarization that occurs in a sound-receptor cell is proportional to the volume (loudness)of the sound.

Accepted Answer

A) True 
 B)False

Question 14

Elephants hear sounds that are too low for humans to hear.This sensitivity is primarily due to the differences in the _____.

Accepted Answer

A) arrangement and shape of the ossicles 
B) flexibility of the basilar membrane in the cochlea 
C) size and flexibility of the tympanic membrane (eardrum) 
D) size and shape of the outer ear 
E) All of the above apply. 
A) arrangement and shape of the ossicles 
B) flexibility of the basilar membrane in the cochlea 
C) size and flexibility of the tympanic membrane (eardrum) 
D) size and shape of the outer ear 
E) All of the above apply.

Question 15

Which of the following is a false description of the transduction of a stimulus by sensory receptors into signals in the form of action potentials?

Accepted Answer

A) Pressure from sound waves bends cilia in specialized hearing cells,causing ion channels in the plasma membrane to open or close and resulting in a change in ion flow that depolarizes or hyperpolarizes the membrane. 
B) Light can cause some molecules to change conformation,which then triggers a cascade of events leading to a change in the cell's membrane. 
C) Molecules in the air travel up the nose to mucous membranes,where they bend cilia in hair cells,open ion channels,and cause depolarization of the cell membrane. 
D) Na⁺ and H⁺ can flow through sodium and proton channels respectively to directly depolarize the cell membranes of some taste cells,causing the salty or sour taste sensations. 
E) Many types of molecules can bind to a variety of receptors in taste cells,leading to depolarization of the cell membrane and causing the taste sensation of bitterness. 
A) Pressure from sound waves bends cilia in specialized hearing cells,causing ion channels in the plasma membrane to open or close and resulting in a change in ion flow that depolarizes or hyperpolarizes the membrane. 
B) Light can cause some molecules to change conformation,which then triggers a cascade of events leading to a change in the cell's membrane. 
C) Molecules in the air travel up the nose to mucous membranes,where they bend cilia in hair cells,open ion channels,and cause depolarization of the cell membrane. 
D) Na⁺ and H⁺ can flow through sodium and proton channels respectively to directly depolarize the cell membranes of some taste cells,causing the salty or sour taste sensations. 
E) Many types of molecules can bind to a variety of receptors in taste cells,leading to depolarization of the cell membrane and causing the taste sensation of bitterness.

Question 16

Which type of receptor would you expect to be most abundant in the antennae of a moth?

Accepted Answer

A) thermoreceptors 
B) mechanoreceptors 
C) chemoreceptors 
D) electroreceptors 
E) nociceptors 
A) thermoreceptors 
B) mechanoreceptors 
C) chemoreceptors 
D) electroreceptors 
E) nociceptors

Question 17

If a biochemist discovered an enzyme inhibitor for the enzyme photodiesterase (PDE)how would vision be affected if this enzyme inhibitor was applied to a vertebrate eye?

Accepted Answer

A) The opsins found in cones would not be differentiated into the red,blue,and green proteins,causing the animals to be color blind. 
B) The cGMP-gated sodium channels would remain open,glutamate would be continuously discharged at the synapses,and the brain would not detect light absorbed by the rod cells. 
C) The lens could not be appropriately adjusted to focus light on the retina,resulting in either nearsightedness or farsightedness. 
D) All of the above answers are correct. 
A) The opsins found in cones would not be differentiated into the red,blue,and green proteins,causing the animals to be color blind. 
B) The cGMP-gated sodium channels would remain open,glutamate would be continuously discharged at the synapses,and the brain would not detect light absorbed by the rod cells. 
C) The lens could not be appropriately adjusted to focus light on the retina,resulting in either nearsightedness or farsightedness. 
D) All of the above answers are correct.

Question 18

Damage to sensory receptor cells could result in _____.

Accepted Answer

A) hallucinations 
B) inaccurate integration of sensory information 
C) an inability to detect sensory information 
D) an inability to detect sensory information and hallucinations 
E) an inability to detect sensory information,inaccurate integration of sensory information,and hallucinations 
A) hallucinations 
B) inaccurate integration of sensory information 
C) an inability to detect sensory information 
D) an inability to detect sensory information and hallucinations 
E) an inability to detect sensory information,inaccurate integration of sensory information,and hallucinations

Question 19

Compared to human eyes,the eyes of cephalopods (squid and octopus)_____.

Accepted Answer

A) are extremely similar,with no significant differences 
B) are not camera eyes and do not have a single lens 
C) are inferior because they have few photoreceptors 
D) do not have a blind spot 
A) are extremely similar,with no significant differences 
B) are not camera eyes and do not have a single lens 
C) are inferior because they have few photoreceptors 
D) do not have a blind spot

Question 20

Partial or complete loss of hearing (deafness)can be caused by damage to the _____.

Accepted Answer

A) axons of the neurons associated with each hair cell that carry information to the brain 
B) hair cells (the sensory receptors)in the cochlea 
C) tympanic membrane,or eardrum 
D) axons of the neurons associated with each hair cell that carry information to the brain or hair cells (the sensory receptors)in the cochlea 
E) Damage to all of the above can cause complete or partial deafness. 
A) axons of the neurons associated with each hair cell that carry information to the brain 
B) hair cells (the sensory receptors)in the cochlea 
C) tympanic membrane,or eardrum 
D) axons of the neurons associated with each hair cell that carry information to the brain or hair cells (the sensory receptors)in the cochlea 
E) Damage to all of the above can cause complete or partial deafness.

Exam 46: Animal Sensory Systems and Movement

A person able to hear only high-frequency sounds would probably have which of the following structural problems in the ear?

When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ),a series of events occurs that leads to muscle contraction.Which of the following events will occur last (i.e. ,after all of the others)?

Two students studying physiology taste a known "bitter" substance,and both report sensing bitterness.They then sample another substance.Student A reports sensing both a bitter taste and a salty taste,but student B reports only a salty taste.What is the most logical explanation?

Training for long-distance running causes a significant increase in _____.

What is the function of the cochlea?

Researchers surgically fuse two of the three ossicles in the inner ear of a mouse,effectively leaving two functional,linked ossicles in place of three.When the mouse's hearing is tested,what outcome would be expected?

Hair cells in the vertebrate ear are responsible for transducing sound pressure waves.Ion channels in the hair cell membrane open when _____.

When a neurobiologist is interested in determining if an animal can see in color what structures are they looking for in the eye?

When a doctor tests your patellar reflex by tapping the tendon on the front of your knee,your lower leg comes forward.Which muscle relaxes in this reflex?

What would be the effect on muscle contraction if troponin were experimentally altered to no longer interact with tropomyosin,so the complex could no longer bind to actin?

Mammals have a family of 500 and 1000 genes that encode receptor proteins on the surface of odor-receptor neurons.If all mammals have these genes,why do some mammals have a better sense of smell than others do?

The amount of depolarization that occurs in a sound-receptor cell is proportional to the volume (loudness)of the sound.

Elephants hear sounds that are too low for humans to hear.This sensitivity is primarily due to the differences in the _____.

Which of the following is a false description of the transduction of a stimulus by sensory receptors into signals in the form of action potentials?

Which type of receptor would you expect to be most abundant in the antennae of a moth?

If a biochemist discovered an enzyme inhibitor for the enzyme photodiesterase (PDE)how would vision be affected if this enzyme inhibitor was applied to a vertebrate eye?

Damage to sensory receptor cells could result in _____.

Compared to human eyes,the eyes of cephalopods (squid and octopus)_____.

Partial or complete loss of hearing (deafness)can be caused by damage to the _____.

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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