BiSci 4 Mastering Biology

hyperpolarization results from __________. a. slow closing of voltage-gated K+ channels b. fast closing of voltage-gated K+ channels c.slow closing of voltage-gated Na+ channels

slow closing of voltage-gated K+ channels

What part of a neuron relays signals from one neuron to another neuron or to an effector? A.dendrite B. axon hillock C. synaptic terminal D. axon E. node of Ranvier

synaptic terminal

Neurons store neurotransmitter molecules in vesicles located within _____. A. myelin B.the synaptic cleft C. dendrites D. synaptic terminals

synaptic terminals

Stereocilia are embedded in a gelatinous structure known as the ________. oval window basilar membrane organ of Corti ampullae tectorial membrane

tectorial membrane

During an action potential a.sodium ions move into the neuron, then potassium ions move in. b.the inside of the neuron becomes positively charged relative to the outside. c.potassium ions move into the neuron. d. potassium channels open first, followed by sodium channels. e. the inside of the neuron becomes negatively charged relative to the outside.

the inside of the neuron becomes positively charged relative to the outside.

Your cousin has a cochlear implant to aid in her hearing. How does this implant work? With electrodes. With low-level radiation. With replacement hair cells. With low-frequency vibrations.

With electrodes.

The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____. a. K+; Na+ b.Na+; Cl- c.Na+; K+ d.K+; Cl

k+; na+

The _____ changes shape to focus light on the retina. vitreous humor blind spot cornea lens optic nerve

lens

Which hormone stimulates hormone production by the ovaries and testes? -progesterone -testosterone -glucocorticoids -luteinizing hormone (LH) -estrogens

luteinizing hormone (LH)

When a hormone binds to a receptor, the resulting molecule is called a(n) ________. -hormone-receptor complex -amino acid complex -hormone-membrane complex -hormone-DNA complex -hormone-steroidal complex

hormone-receptor complex

Which of these glands secretes releasing hormones? hypothalamus adrenal cortex thymus ovaries testes

hypothalamus

what is the value for the resting membrane potential for most neurons? a. -90 mV b. +30 mV c.-70 mV

-70 mV

A neuron has a resting potential of about _____ millivolts. a. +50 b.+35 c.-55 d.-70 e. -80

-70

What is the magnitude (amplitude) of an action potential? a.70 mV b.100 mV c.30 mV

100 mV

You are a pediatrician. Which of the following patients is most likely to have an eating disorder? -A 14 year old girl with Type I diabetes. -A 16 year old girl without diabetes. -A 15 year old boy with Type II diabetes. -A 12 year old boy without diabetes.

A 14 year old girl with Type I diabetes.

You work for a pharmaceutical company. Based on this research, which of the following should you pursue for a new cancer treatment? -A drug that promotes fibroblastic activation protein. -A drug that has no effect on fibroblastic activation protein. -A drug that creates fibroblastic activation protein. -A drug that inhibits fibroblastic activation protein.

A drug that inhibits fibroblastic activation protein.

You are an oncologist. A patient presents with metastatic colon cancer. Which of the following are you most likely to find at the tumor sites? -A loss of collagen. -No change in collagen at the tumor sites. -Collagen with a different structure at the tumor sites. -Excess collagen at the tumor sites.

A loss of collagen.

Which of the following people is most likely to suffer ketoacidosis? -A person with Type I diabetes that heavily restricts insulin. -A person with Type II diabetes that takes extra insulin. -A person with Type I diabetes that takes extra insulin. -A person with Type II diabetes that slightly restricts insulin.

A person with Type I diabetes that heavily restricts insulin.

If a gene is activated by a hormone, what is the most likely chain of events? -Transcription of mRNA and translation of the message into a protein both take place in the nucleus. The new protein then leaves the nucleus and enters the cytoplasm, where it initiates various cellular events. -A protein is produced directly from the DNA. This stimulates other molecules to produce mRNA. This mRNA leaves the nucleus and initiates the response in the cytoplasm. -Transcription of mRNA and translation of the message into a protein both take place in the cytoplasm. This is caused by an electrical stimulus from the complexing of the hormone and the gene. -A strand of mRNA is transcribed in the nucleus. It leaves the nucleus for the cytoplasm. The message is translated into a new protein. -The gene triggers other components in the nucleus. This leads to a cascade of events. More DNA is produced, and eventually a new protein is produced. This protein leaves the nucleus and goes to the cytoplasm, where it initiates the events attributed to the hormone.

A strand of mRNA is transcribed in the nucleus. It leaves the nucleus for the cytoplasm. The message is translated into a new protein.

Which of the following statements about the functions of hormones is MOST correct? -Hormones affect energy utilization. -Hormones can affect the activities of the plasma membrane. -Hormones influence protein synthesis. -Hormones may be involved in secretory activity. -All of the listed responses are correct.

All

Alzheimer's is a neurological disease with loss of memory and motor skills -There is a link between improperly folded proteins and disease in both mad cow disease and Alzheimer's disease. -High heat and a change in pH can denature a protein. -The three-dimensional shape of a protein is critical for the functioning of that protein. -Alzheimer's disease causes proteins in the brain to become improperly folded.

Alzheimer's disease causes proteins in the brain to become improperly folded.

Which of the following best describes Alzheimer's disease? -Alzheimer's is a neurological disease with loss of memory and motor skills. -Alzheimer's only occurs in more developed countries, like the United States. -Alzheimer's only occurs in the elderly, and is expressed as shakes and tremors. -Alzheimer's occurs most often in people under the age of 40.

Alzheimer's is a neurological disease with loss of memory and motor skills

_____ are the main male hormones. -Progesterones -Mineralocorticoids -Androgens -Luteinizing hormones -Estrogens

Androgens

What occurs when the action potential reaches the synaptic terminal? A. Sodium and calcium ions rush back and forth through the voltage channels, and this allows the electrical impulse to cross the synapse B .Calcium ions rush into the presynaptic terminal. C. Calcium ions rush out of the presynaptic terminal. D. Sodium ions rush into the terminal and complex with the neurotransmitter vesicles.

Calcium ions rush into the presynaptic terminal.

Which of the following statements about color vision is NOT true? The brain combines signals from the different types of cone cells to differentiate the colors of the visible spectrum. Cone cells use different retinal molecules to absorb different wavelengths of light. Activation of opsin by retinal triggers a cascade of events that sends signals to the brain. There are three types of cone cells, corresponding to the three primary colors of light: red, green, and blue.

Cone cells use different retinal molecules to absorb different wavelengths of light.

You are a genetic engineer focused on fixing the genetic mutations that cause the most common form of congenital deafness. Which of the following proteins do you need repaired genes to produce? Connexin 26 Tubulin Elastin Lectin

Connexin 26

Which of the following is true? -Fibroblastic activation protein destroys the immune system. -Fibroblastic activation inhibits the work of the immune system. -Fibroblastic activation enhances the immune system. -Fibroblastic activation protein has no effect on the immune system.

Fibroblastic activation inhibits the work of the immune system.

You just ate about half your birthday cake. Which of the following is happening in your body? -Glucose decreases, insulin increases, glucagon decreases. -Glucose increases, insulin increases, glucagon decreases. -Glucose increases, insulin increases, glucagon increases. -Glucose increases, insulin decreases, glucagon increase

Glucose increases, insulin increases, glucagon decreases.

According to the video, which of the following describes the impact of Alzheimer's in the United States by the year 2050? -Almost everyone in the United States will have Alzheimer's by 2050. -It is projected that there will be 16 million cases by 2050, with an annual health care cost of $1 trillion. -Scientists are close to a cure for Alzheimer's, so the disease will be eradicated by 2050. -The incidence of Alzheimer's will likely decrease by 2050, as heart disease, stroke, cancer, and diabetes increase

It is projected that there will be 16 million cases by 2050, with an annual health care cost of $1 trillion.

Which statement accurately describes the myelin sheath? A. It is found on all axons outside the brain and spinal cord (central nervous system) B. It speeds up the conduction of nervous impulses. C. It allows the nodes of Ranvier to act as an electrical insulator D. It prevents saltatory conduction.

It speeds up the conduction of nervous impulses

After years of listening to loud music, your inner ear hair cells are damaged. Which of the following will be the result? Everything will sound hollow. Loss of sound signal transduction. There will be no impact on your hearing. Loss of amplification.

Loss of sound signal transduction.

The concentrations of which two ions are highest outside the cell. -Na+ and Cl- -Na+ and A- (negatively charged proteins) -K+ and A- (negatively charged proteins) -K+ and Cl-

Na+ and Cl-

Which of the following events is the first to occur during an action potential? -Sodium ions flow into the neuron, making the inside of the neuron positively charged relative to the outside. - Sodium channels close. -Potassium ions flow out of the neuron. -Potassium channels open. -Sodium channels open.

Sodium channels open

Which of the following pancreatic cancer patients likely has the best prognosis? -One with slightly above average fibroblastic activation protein. -One with very high fibroblastic activation protein. -One with moderately low fibroblastic activation protein. -One with no detectable fibroblastic activation protein.

One with no detectable fibroblastic activation protein.

If the level of calcium in the blood falls below the homeostatic level, which of the following would be true? -Bones would begin to store more calcium. -Parathormone levels in the body would increase. -The secretion of calcitonin would increase. -All of these statements would be true if blood calcium levels are too low.

Parathormone levels in the body would increase

With regard to dynamic equilibrium and static equilibrium, we can say that ________. Receptors in the semicircular canals are responsible for static equilibrium, and receptors in the vestibule are responsible for dynamic equilibrium. Receptors in both the semicircular canals and the vestibule are responsible for both dynamic and static equilibrium. Receptors in the semicircular canals are responsible for dynamic equilibrium, and receptors in the vestibule are responsible for static equilibrium.

Receptors in the semicircular canals are responsible for dynamic equilibrium, and receptors in the vestibule are responsible for static equilibrium.

As a generalization, which of the following can we correctly say about photoreceptors? Rod cells are responsible for color vision. All retinal cells are responsible for dim vision. Rod cells and cone cells are equally responsible for dim light vision, but color vision is the responsibility of specialty color cells.' Rods detect color and cones detect dim light. Rods detect dim light and cones detect color.

Rods detect dim light and cones detect color.

What type of cell makes up the myelin sheath of a motor neuron? A.astrocytes B. microglial cells C. Ranvier cells D. ependymal cells E. Schwann cells

Schwann cells

When speaking of myelinating glial cells, we can correctly say that ________. A. Schwann cells are glial cells found outside the brain and spinal cord; oligodendrocytes are glial cells found in the brain and spinal cord B.Schwann cells and oligodendrocytes form tight layers of overlapping cells C. Schwann cells are glial cells found within the brain and spinal cord; oligodendrocytes are glial cells found outside the brain and spinal cord

Schwann cells are glial cells found outside the brain and spinal cord; oligodendrocytes are glial cells found in the brain and spinal cord

Which of the following statements about the human ear is true? A. The stereocilia of the outer hair cells in the cochlea are embedded in the basilar membrane. B. The brain interprets input from different regions of the basilar membrane as different pitches. C. The organ of Corti contains sensory receptors and is located in the eardrum. D. The pinna amplifies sound coming into the ear.

The brain interprets input from different regions of the basilar membrane as different pitches.

How are hormones related to the interaction of the nervous system and muscular system? -Muscle movement stimulates the nervous system. This, in turn, stimulates the release of hormones. -The nervous system stimulates muscle movement. This, in turn, stimulates the release of hormones. -The nervous system can control muscle movement by controlling the release of hormones. -Muscle movement stimulates the release of hormones. This, in turn, stimulates the nervous system.

The nervous system can control muscle movement by controlling the release of hormones.

When the neurotransmitter crosses the synapse, what happens? -The neurotransmitters bind to the membrane. This causes the ion channels to close. -The neurotransmitter causes the channel to open, and this can cause a depolarization of the postsynaptic membrane. -The neurotransmitter binds to the axon of the postsynaptic neuron, and this stimulates the nucleus in the cell body to generate another action potential.

The neurotransmitter causes the channel to open, and this can cause a depolarization of the postsynaptic membrane.

Which of the following does NOT occur in a healthy person's body after meals? -The pancreas secretes insulin. -Muscle cells take up glucose. -The liver stops breakdown of glycogen. -The pancreas secretes glucagon.

The pancreas secretes glucagon.

Which of the following statements is NOT true? The optic nerve carries the optic messages to the brain. The photoreceptors are on the innermost layer (the layer closest to the center) of the retina. The different opsin molecules determine which wavelength of light is best absorbed by that molecule Cones are responsible for the reception of bright light.

The photoreceptors are on the innermost layer (the layer closest to the center) of the retina.

This study most strongly suggests which of the following? -The stroma does not play a role in tumor growth, but does play a role in metastasis of cancer. The stroma plays a role in tumor growth, but does not play a role in metastasis of cancer. The stroma does not play a role in tumor growth or in metastasis of cancer. The stroma plays a role in tumor growth and metastasis of cancer.

The stroma plays a role in tumor growth and metastasis of cancer.

Which of these statements best describes a synapse? A. Synapse is a synonym for "electrical stimulation." B. Synapse is a term used to define the total process of the impulse moving from the presynaptic neuron to the postsynaptic neuron C.The synapse includes the space between the presynaptic membrane and the postsynaptic membrane. D.The synapse is the membrane on the postsynaptic terminal.

The synapse includes the space between the presynaptic membrane and the postsynaptic membrane.

Which of the following is NOT a method for clearing neurotransmitters from a synapse? -They are "recycled" by the presynaptic terminal. -They can be taken up into the presynaptic terminal. -They can be taken up into the postsynaptic neuron. -They can be enzymatically degraded.

They can be taken up into the postsynaptic neuron.

You are a gene technician for a major medical company, working on improving the use of adeno-associated virus and producing it in mass quantity. What is the purpose of this? To use as a gene vector. To transfer new proteins into damaged cells of patients. To alter DNA in patients by adding synthetic base pairs. To enhance DNA removal in patients.

To use as a gene vector

The mechanism by which the neurotransmitter is returned to a presynaptic neuron's axon terminal is specific for each neurotransmitter. Which of the following neurotransmitters is broken down by an enzyme before being returned? a. glutamate b. acetylcholin

acetylcholin

The loudness or intensity of a sound wave is related to its __________. pitch frequency duration amplitude

amplitude

Which of these causes the release of neurotransmitter molecules? A. the receipt of a signal from the postsynaptic neuron B. an action potential reaching the end of the cell body C.an action potential reaching the end of the axon D. an action potential reaching the end of the dendrite

an action potential reaching the end of the axon

Whether a sound is interpreted by the brain as a higher or lower pitch is determined by the ________. the oval window and the round window the pressure changes on the basilar membrane anatomy of the basilar membrane position of the Eustachian (pharyngotympanic) tube

anatomy of the basilar membrane

What hormone promotes water retention by the kidneys? -follicle-stimulating hormone (FSH) -prolactin -antidiuretic hormone (ADH) -melatonin -glucagon

antidiuretic hormone (ADH)

Receptors for nonsteroid hormones are located in _____. -the extracellular fluid -the cytoplasm -the nucleus -the cytosol -association with a cell's plasma membrane

association with a cell's plasma membrane

An action potential moves along a(n) _____. -myelin sheath - axon -nucleus -synapse -cell body

axon

The part of the nerve cell responsible for origination of the nerve impulse is the ________. A. axon hillock B.dendrite C. nutritional center D. axon

axon hillock

Where in the neuron is an action potential initially generated? -axon hillock -anywhere on the axon -soma and dendrites

axon hillock

Name the three principal parts of the nerve cell.

axon, dendrites, cell body

A nerve impulse moves AWAY from a neuron's cell body along _____ A.dendrites B. Nissl bodies C. synapses D. axons E. glia

axons

Noah is a 4-year-old boy who has a middle ear infection. The cause of the infection could be __________. noise pollution bacteria that spread to the ear from a sore throat excessive wax buildup in the ear canal water that was trapped in the ear after bathing

bacteria that spreads to the ear from a sore throat

Insulin is used to regulate sugar where? -urine -pancreas -blood -spleen

blood

Sound waves are converted into mechanical movements by the __________. round window oval window bones of the middle ear cochlea

bones of the middle ear

If this research proves fruitful and works in humans, which of the following will be true? Only inner ear hairs will see improvement. Only outer ear hairs will see improvement. Neither outer nor inner ear hairs will see improvement. Both outer and inner ear hairs will see improvement.

both outer and inner ear hairs will see improvement

During depolarization, which gradient(s) move(s) Na+ into the cell? -only the electrical gradient -Na+ does not move into the cell. Na+ moves out of the cell. -only the chemical gradient -both the electrical and chemical gradients

both the electrical and chemical gradients

Which hormone opposes the action of parathyroid hormone? -calcitonin -insulin -thyroxine -thymosin -glucagon

calcitonin

A neuron's nucleus is located in its _____. A. cell body B. axon C. myelin sheath D. dendrite E. synaptic terminals

cell body

Binding of a neurotransmitter to its receptors opens __________ channels on the __________ membrane. a.voltage-gated; presynaptic b.chemically gated; presynaptic c.voltage-gated;; postsynaptic d.chemically gated; postsynaptic

chemically gated; postsynaptic

The eye acts like a camera. Which structure or structures bend(s) the light coming into the eye so that clear, camera-like vision can be achieved? cornea and lens cornea, lens, and retina retina only lens only cornea only

cornea and lens

Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor? -estrogen -epinephrine -cellulose -oxytocin -starch

estrogen

nerve impulse moves TOWARD a neuron's cell body along _____ A. dendrites B.synaptic terminas C. oligodendrocytes D. axons E. nodes of Ranvier

dendrites

Binding of the neurotransmitter to its receptor causes the membrane to __________.: a.either depolarize or hyperpolarize b.hyperpolarize c.depolarize

either depolarize or hyperpolarize

Which of these hormones are responsible for the "fight or flight" response to danger? -insulin and glucagon -thyroxine and calcitonin -androgens and estrogens -antidiuretic hormone (ADH) and oxytocin -epinephrine and norepinephrine

epinephrine and norepinephrine

Which of these is a nonsteroid hormone? -estrogen -testosterone -both estrogen and testosterone -oxytocin -epinephrine and oxytocin

epinephrine and oxytocin

Which of the following sequences represents the path by which sound waves travel through the ear? View Available Hint(s) External auditory canal, eardrum, oval window, cochlea Eardrum, stapes, cochlea, Eustachian tube Cochlea, round window, oval window, eardrum

external auditory canal, eardrum, oval window & cochlea

T/F : Motion sickness is caused by an imbalance in the three semicircular canals.

false

T/F : The adrenal gland secretes hormones that slow down the heart rate and lower blood glucose levels.

false

T/F : The pituitary gland is located behind the thyroid gland.

false

You are an emergency room doctor and a patient presents with ketoacidosis. Which of the following is rapidly being broken down? -muscle -bone -glucose -fat

fat

Part complete The greatest concentration of cones is found in the __________. sclera lens fovea ciliary body

fovea

The _____ is the region of the eye where photoreceptors are most highly concentrated. lens fovea optic nerve pupil sclera

fovea

The place on the eye where we find the greatest visual acuity, and thus the place we "use" when we need to focus on details, is the ________. cornea retina lens fovea optic nerve

fovea

Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress. -melatonin -insulin -glucocorticoids -thymosin -parathyroid hormone

glucocorticoids

Receptors in the vestibular apparatus respond to changes in __________. brightness of light position of limbs taste head position

head position

Amplifying the sound waves is the primary function of which part of the ear? pinna outer ear, middle ear, and inner ear inner ear middle ear outer (external) ear

middle ear

Which of the following statements is most accurate regarding the rod cells (light/dark receptors) and cone cells (color receptors) in your retina? Your retina has.... -many more cones than rods. -many more rods than cones. -the same number of rods and cones, distributed unevenly. - same number of rods and cones, distributed evenly

more rods than cones

Axons insulated by a(n) _____ are able to conduct impulses faster that those not so insulated. A. node of Ranvier B. synaptic terminal C. myelin sheath D. layer of asbestos E. astrocytes

myelin sheath

A molecule that carries information across a synaptic cleft is a a. receiving neuron b. synapse c. sending neuron d. neurotransmitter e. synaptic cleft

neurotransmitter

An impulse relayed along a myelinated axon "jumps" from _____ to _____. A.oligodendrocyte ... Schwann cell B. node of Ranvier ... Schwann cell C. node of Ranvier ... node of Ranvier D. Schwann cell ... Schwann cell E. Schwann cell ... node of Ranvier

node of Ranvier ... node of Ranvier

How do nonsteroid hormones differ from steroid hormones? -nonsteroid hormones bind to a cell's DNA; steroid hormones do not bind to a cell's DNA -nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways -the action of nonsteroid hormones never affects gene expression; the action of steroid hormones always affects gene expression -nonsteroid hormones bind to cytoplasmic receptors; steroid hormones bind to plasma membrane receptors nonsteroid hormones are fat-soluble; steroid

nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways

Which of the following is true? -People with Type I diabetes do require insulin, while people with Type II diabetes may or may not require insulin. -People with Type I diabetes and Type II diabetes require insulin. -People with Type I diabetes do require insulin, while people with Type II diabetes do not require insulin. -People with Type I diabetes may or may not require insulin, while people with Type II diabetes do require insulin.

people with Type I diabetes do require insulin, while people with Type II diabetes may or may not require insulin.

In a synapse, neurotransmitters are stored in vesicles located in the __________. a. synaptic cleft b. postsynaptic neuron c. presynaptic neuron

presynaptic neuron

Which of the following is the correct sequence for the electrical transmission of a nerve impulse? A. postsynaptic neuron, synapse, presynaptic neuron B. synapse, presynaptic neuron, postsynaptic neuron C. synapse, postsynaptic neuron, presynaptic neuron D. presynaptic neuron, synapse, postsynaptic neuron

presynaptic neuron, synapse, postsynaptic neuron

Which hormone stimulates milk production? -parathyroid hormone -mineralocorticoids -prolactin -thyroid-stimulating hormone (TSH) -thymosin

prolactin

The __________ determines the amount of light that enters the eye. fovea pupil cornea retina

pupil

What name is given to the opening that allows light into the interior of the eye? sclera pupil ligament optic nerve retina

pupil

When considering receptors for hormone molecules, we can say that, in general, ________. -receptors for both lipid-soluble and lipid-insoluble hormones are found in or on the cell membrane -receptors for both lipid-soluble and lipid-insoluble hormones are found within the cell and usually within the nucleus -receptors for lipid-soluble hormones are on or in the cell membrane, whereas receptors for lipid-insoluble hormones are inside the cell -receptors for both lipid-soluble and lipid-insoluble hormones are about equally distributed within the cell and as parts of the cell membrane -receptors for lipid-soluble hormones are inside the cell, whereas receptors for lipid-insoluble hormones are on or in the cell membrane

receptors for lipid-soluble hormones are inside the cell, whereas receptors for lipid-insoluble hormones are on or in the cell membrane

Sodium-potassium pumps a.move only sodium ions into the cell. b.are open all the time, allowing potassium ions to leave the cell. c. move both sodium and potassium ions into the cell. d. do not require energy from ATP. e. restore the distribution of ions inside and outside a neuron's membrane following an action potential.

restore the distribution of ions inside and outside a neuron's membrane following an action potential.

What name is given to the tough layer that forms the "white" of the eye? blind spot choroid fovea sclera aqueous humor

sclera

A stimulus has opened the voltagegated sodium channels in an area of a neuron's plasma membrane. As a result, _____ rushes into the neuron and diffuses to adjacent areas; this in turn results in the _____ in the adjacent areas. -potassium ... opening of voltagegated potassium channels -sodium ... opening of voltagegated sodium channels - sodium ... closing of voltagegated sodium channels -potassium ... opening of voltagegated sodium channels

sodium ... opening of voltage-gated sodium channels

As an action potential moves along an axon, we could say that ________. -calcium gates -potassium gates -sodium gates -both sodium and potassium gates -open at the same time

sodium gates

The spiral organ (of Corti) is important in sensing __________. light body movement degree of muscle contraction sound

sound

Which type of hormone is most likely to react with and activate a portion of a DNA molecule? -All types of hormones react with and activate a portion of a DNA molecule. -carbohydrate -steroid -protein -amino acid

steroid

The space between an axon of one neuron and the dendrite of another neuron is called a(n) _____. A. synaptic cleft B. internodes C. synapse D. synaptic terminal

synaptic cleft

In a resting nerve cell membrane (think axon), the electrical relationship between the fluid inside the membrane (inside the cell) and the fluid outside the membrane (extracellular fluid) is as follows: ________. -the interior is negative relative -the exterior the interior is positive relative to the exterior

the interior is negative relative

What does saltatory conduction mean? Saltatory conduction means that .... A. the impulse starts at the cell's nucleus rather than at the axon hillock. B. the nerve impulse seems to jump from one node to the next—and is regenerated as it speeds along. C. the impulse is regulated by the axons and dendrites working in unison.

the nerve impulse seems to jump from one node to the next—and is regenerated as it speeds along

Steroid hormone-receptor complexes act in _____. -the nucleus -lysosomes -vesicles -the cytoplasm -the plasma membrane

the nucleus

The repolarization phase of an action potential results from __________. a. the closing of voltage-gated Na+ channels b. the opening of voltage-gated Na+ channels c. the closing of voltage-gated K+ channels d. the opening of voltage-gated K+ channels

the opening of voltage-gated K+ channels

The blind spot of the eye is __________. the region of the eye where rods outnumber cones the region where the ciliary muscle attaches the region where the optic nerve leaves the eye located in the cornea

the region where the optic nerve leaves the eye

At rest, which of these plays a role in establishing the charge differential across a neuron's plasma membrane? -the sodium-potassium pump moving sodium ions into the neuron and potassium ions out of the neuron - the diffusion of sodium ions out of the neuron -the diffusion of potassium ions into the neuron -the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron -the diffusion of sodium ions into the neuron

the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron

When a neuron is at its resting potential -there are more potassium ions inside the neuron than outside. -gated sodium channels are open. -the inside of the cell is positively charged relative to the outside. -sodium-potassium pumps transport sodium ions into the cell.

there are more potassium ions inside the neuron than outside.

Which of the following statements is correct? -Alzheimer's disease causes betaamyloid plaques to form in the brain. -There is a correlation between betaamyloid plaques and the severity of Alzheimer's disease. -The presence of betaamyloid plaques in the brain causes Alzheimer's disease. -There is no correlation between betaamyloid plaques and the severity of Alzheimer's disease.

there is a correlation between beta-amyloid plaques and the severity of Alzheimer's disease.

The primary reason steroid hormones usually act slowly is that _____. -they are produced at very low concentrations -acting via a signal transduction pathway makes for slower responses than does directly interacting with a cell's DNA -they are too large to enter a cell and therefore must first bind to a plasma membrane receptor before having an effect on a cell -target cells tend to ignore steroid hormones in favor of nonsteroid hormones -they turn genes on or off and it takes time for gene products to build up or become depleted

they turn genes on or off and it takes time for gene products to build up or become depleted

T/F : Sound waves that enter the human ear are transmitted in fluid only in the inner ear.

true

T/F : The primary reason for hearing loss in the elderly is thickening of the eardrum.

true

An action potential releases neurotransmitter from a neuron by opening which of the following channels? a.voltage-gated K+ channels b.chemically gated Ca2+ channels c.voltage-gated; Ca2+ channels d.voltage-gated;Na+ channels

voltage-gated; Ca2+ channels

Which of the following statements would be the best way to describe or define the concept of the second messenger? -Second messenger is another name for the steroid hormones. -Second messenger is another term for the amino acid and protein hormones. -When the binding of the hormone to a membrane receptor (the "first messenger") activates another molecule within the cell (often cyclic AMP), that activated molecule is the second messenger. -Second messenger is another name for cyclic AMP.

when the binding of the hormone to a membrane receptor (the "first messenger") activates another molecule within the cell (often cyclic AMP), that activated molecule is the second messenger.