WorksheetsBiology 1082 #4
Total questions: 71
Worksheet time: 1hrs 11mins
The striated appearance of skeletal muscle is due to the
dark color of myosin.
multiple nuclei per fiber.
regular arrangement of filaments.
dense array of microtubules.
Which of the following statements about the molecular arrangement of actin and myosin in myofibrils is false?
A thin filament consists of actin and tropomyosin.
Two chains of actin monomers are twisted into a helix.
Two strands of tropomyosin lie in the grooves of the actin.
Troponin forms the head of the myosin molecule.
Shown below is an electron micrograph of part of a myofibril from a relaxed muscle fiber. Which of the labeled regions will NOT shorten when the muscle contracts?
A band
H band
Sarcomere
I band
When animals die, muscles stiffen in rigor mortis because
muscles cannot contract without ATP.
actin and myosin cannot bind without ATP.
actin and myosin cannot separate without ATP.
ATP is required for synthesis of protein filaments.
What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?
Action potentials would be continuously generated, causing convulsive muscle contractions.
Muscle contractions would be prevented, causing paralysis.
Muscle contractions could still occur, but relaxation of the muscle would be impaired.
Action potentials would be continuously generated, causing convulsive musclecontractions; muscle contractions would then be prevented, causing paralysis.
The structure enabling depolarization to travel deep into the muscle fiber is the ______.
sarcomere
motor unit
T tubule
sarcoplasmic reticulum
A salmon follows a scent trail upstream to find its way back to the stream where it hatched. What type of sensory receptor cell would it use?
Thermoreceptors
Chemoreceptors
Mechanoreceptors
Electroreceptors
Which of the following statements about human gustation is false?
Taste bud cells are relatively short lived because of the high degree of abrasion they encounter.
Taste buds are confined to the oral cavity.
Changes in the membrane potential of the taste bud sensory cells cause them to release neurotransmitter onto the dendrites of sensory neurons.
Humans perceive only three categories of tastes: sweet, sour, and bitter.
The frequency at which a single neuron can “fire” action potentials is limited by the
number of synapses that the neuron forms.
number of other cells that the neuron contacts.
refractory period for the neuron’s Na+ channel.
length of the axon of the neuron.
The middle ear converts _____.
air pressure waves to fluid pressure waves
fluid pressure waves to air pressure waves
air pressure waves to nerve impulses
fluid pressure waves to nerve impulses
Hair cells in the vertebrate ear are responsible for transducing sound pressure waves. Ion channels in the hair cell membrane open when _____.
a chemical ligand binds to the ion channel
light is absorbed by a molecule in the membrane
the cell membrane reaches a threshold voltage
the membrane is distorted mechanically
Sensory transduction of light in the vertebrate retina is accomplished by _____.
ganglion cells
amacrine cells
rods and cones
bipolar cells
Rods exposed to light will _____.
depolarize due to the opening of sodium channels
hyperpolarize due to the closing of sodium channels
depolarize due to the opening of potassium channels
hyperpolarize due to the closing of potassium channels
Which of the following sensory receptors is correctly paired with its category?
hair cell — mechanoreceptor
muscle spindle — electromagnetic receptor
taste receptor — mechanoreceptor
rod — chemoreceptor
Calculation, contemplation, and cognition are human activities associated with increased activity in the _____.
hypothalamus
cerebrum
cerebellum
spinal cord
Unmyelinated neurons are most abundant in the
grey matter of the brain and white matter of the spinal cord.
white matter in the brain and white matter of the spinal cord.
white matter of the brain and grey matter of the spinal cord.
grey matter of the brain and grey matter of the spinal cord.
The divisions of the nervous system that have antagonistic, or opposing, actions are
forebrain and hindbrain.
sympathetic and parasympathetic systems.
presynaptic and postsynaptic membranes.
central nervous system and peripheral nervous system.
Central coordination of vertebrate biological rhythms in physiology and behavior reside in the
thalamus.
hypothalamus
cerebrum
cerebellum
Neurons that transmit information from sensory cells to the central nervous system are part of the
brain
peripheral nervous system.
spinal cord.
central nervous system.
Immediately after putting on a shirt, your skin might feel itchy. However, this perception soon fades due to
reduced receptor amplification
reduced motor unit recruitment.
sensory adaptation.
the increase of transduction.
In arthropods, locomotion is accomplished by muscles that work against
each other.
the exoskeleton.
a hydrostatic skeleton.
an endoskeleton.
In general, _______ are cells of the nervous system that transduce physical or chemical stimuli into signals that are transmitted to other parts of the nervous system for processing and interpretation.
sensory cells
effectors
glial cells of the blood–brain barrier
nuclei within the midbrain
The generation of action potentials in sensory neurons initiated by changes in pressure is an example of
sensory transduction.
perception
sensory adaptation.
habituation.
Which of the following is not one of the functions of Schwann or oligodendrocyte glial cells?
Supporting neurons during embryonic development
Supplying nutrients
Conducting nerve impulses
Consuming foreign particles
After eating a large meal, which nerves are most active in your digestive system?I. Parasympathetic nervesII. Somatic (motor) nervesIII. Sympathetic nerves
only I
only II
only III
only II and III
Action potentials are also called
potential energy
resting potentials.
nerve impulses.
leak currents.
The vertebrate ectoderm is the origin of the
nervous system.
stomach
pancreas
muscles and bones
A simple nervous system
must include chemical senses, mechanoreception, and vision.
includes sensory information, an integrating center, and effectors.
has information flow in only one direction: toward an integrating center.
has information flow in only one direction: away from an integrating center.
Neurons that transmit information from sensory cells to the central nervous system are part of the
brain
peripheral nervous system.
spinal cord.
central nervous system
In a simple synapse, neurotransmitter chemicals are released by
cell bodies.
axon hillocks.
dendritic membrane.
presynaptic membrane.
Rapid inward diffusion of Na+ produces a dramatic change in membrane potential. What is this event called?
Hyperpolarization
Excitatory postsynaptic potential
Saltatory conduction
Depolarization
Which ion channel is primarily responsible for the action potential?
The voltage-gated sodium channel
The voltage-gated potassium channel
The ligand-gated sodium channel
The ligand-gated potassium channel
The two primary cell types of the nervous system are _______ and _______.
ibroblasts; chondrocytes
neurons; glial cells
epithelial cells; neuromuscular cells
neurons; epithelial cells
The thalamus and hypothalamus develop from the
telencephalon
diencephalon
cerebellum
cerebrum
In general, the more autonomic functions are found in the _______, and the more complex functions are found in the _______.
forebrain; hindbrain
telencephalon; diencephalon
thalamus; hypothalamus
hindbrain; forebrain
In multiple sclerosis the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?
Action potentials move in the opposite direction on the axon.
Action potentials move more slowly along the axon.
Action potentials are entirely negated.
All of the above occurs in multiple sclerosis.
Which of the following is not one of the functions of Schwann or oligodendrocyte glial cells?
Supporting neurons during embryonic development
Supplying nutrients
Conducting nerve impulses
Consuming foreign particles
When several EPSPs arrive at the axon hillock from different dendritic locations, depolarizing the postsynaptic cell to threshold for an action potential, this is an example of
the refractory state.
spatial summation.
tetanus
temporal summation.
When several IPSPs arrive at the axon hillock rapidly in sequence from a single dendritic location, hyperpolarizing the postsynaptic cell more and more and thus preventing an action potential, this is an example of
temporal summation
spatial summation.
the refractory state.
tetanus.
Which of the following statements about a sensory cell is false?
It is specialized for detecting specific kinds of stimuli.
It transduces energy into action potentials.
It generates receptor potentials, which travel long distances.
It can generate action potentials.
Which of the following statements about the auditory functioning of the cochlea is false?
The flexing of the round window follows the flexing of the oval window in a delayed fashion.
The hair cells on the organ of Corti move against the rigid tectorial membrane.
The intensity of the sound determines how many hair cells will be stimulated.
Lower frequency sounds result in the stimulation of hair cells closer to the round window.
A male silkworm moth locates a female at a distance by
flying toward a chemical signal.
flying toward a sound signal.
flying toward anything shaped like a female moth.
emitting a sound as the female approaches.
The activation of a rhodopsin molecule sets off a chain reaction that leads to the
opening of a sodium channel.
closing of a large number of sodium channels.
formation of an activated phosphodiesterase molecule.
activation of a large number of transducing molecules.
Which of the following statements about the functioning of a rod cell is false?
Rhodopsin is located in the stack of disks that is farthest from the light source.
A rod cell is a modified neuron.
The resting potential of a rod cell in the dark is less negative than a typical neuron.
The membrane potential of a rod cell exposed to light becomes more positive.
Which of the following statements about human gustation is false?
Taste bud cells are relatively short lived because of the high degree of abrasion they encounter.
Changes in the membrane potential of the taste bud sensory cells cause them to release neurotransmitter onto the dendrites of sensory neurons.
Humans perceive only three categories of tastes: sweet, sour, and bitter.
Most taste buds are found on the papillae of the tongue.
The generation of action potentials in sensory neurons initiated by changes in pressure is an example of
sensory transduction.
perception.
habituation.
sensory adaptation.
Artificial electrical stimulation of a human's menthol-sensitive neurons would likely produce the sensation of
tactile stimulus.
hot temperature.
cold temperature.
deep pressure.
Mechanoreceptors that react to low frequency waves are part of the
lateral line systems in fish.
eyes in arthropods.
pain receptors in birds.
human sense of taste
The greatest intensity of perceived smell comes from the
odorant that binds to the most receptors.
greatest variety of odorant molecules.
greatest threshold of depolarization.
greatest number of odorant molecules entering the cell.
Shown below is an electron micrograph of part of a myofibril from a relaxed muscle fiber. Which of the labeled regions will NOT shorten when the muscle contracts?
Z line
H band
Sarcomere
I band
The structure enabling depolarization to travel deep into the muscle fiber is the ______.
sarcomere
T tubule
motor unit
sarcoplasmic reticulum
A simple nervous system
must include chemical senses, mechanoreception, and vision.
includes sensory information, an integrating center, and effectors.
has information flow in only one direction: toward an integrating center.
has information flow in only one direction: away from an integrating center.
Neurons that transmit information from sensory cells to the central nervous system are part of the
peripheral nervous system.
brain.
spinal cord.
central nervous system.
In a simple synapse, neurotransmitter chemicals are released by
cell bodies.
axon hillocks.
dendritic membrane.
presynaptic membrane.
Rapid inward diffusion of Na+ produces a dramatic change in membrane potential. What is this event called?
Hyperpolarization
Excitatory postsynaptic potential
Saltatory conduction
Depolarization
Which ion channel is primarily responsible for the action potential?
The voltage-gated sodium channel
The voltage-gated potassium channel
The ligand-gated sodium channel
The ligand-gated potassium channel
The two primary cell types of the nervous system are _______ and _______.
fibroblasts; chondrocytes
neurons; glial cells
epithelial cells; neuromuscular cells
neurons; epithelial cells
The thalamus and hypothalamus develop from the
telencephalon.
diencephalon.
cerebrum.
cerebellum.
In general, the more autonomic functions are found in the _______, and the more complex functions are found in the _______.
forebrain; hindbrain
telencephalon; diencephalon
thalamus; hypothalamus
hindbrain; forebrain
In the spinal cord, the gray matter contains the _______, and the white matter contains the _______.
axons; cell bodies
cell bodies; axons
dorsal horn; ventral horn
ventral horn; dorsal horn
Norepinephrine _______ the heart rate, whereas acetylcholine _______ the heart rate.
decreases; increases
decreases; decreases
increases; decreases
increases; increases
If a patient has an injury in the brain stem, which of the following would be observed?
Auditory hallucinations
Visual hallucinations
An inability to regulate body temperature
An inability to regulate heart function
The fear response that is triggered by a potentially dangerous situation results from activation of the
hippocampus
frontal lobe
amygdala
cortex
Upon witnessing a robber hold up a convenience store at gunpoint, which of the following reactions would your nervous system initiate?
Increased heartbeat
Constriction of airways
Constriction of pupils
Decreased heartbeat
Increased activity in the sympathetic nervous system leads to
relaxation of the airways in the lungs.
decreased heart rate.
increased secretion by the pancreas.
increased contraction of the stomach.
Which of the following is not one of the functions of Schwann or oligodendrocyte glial cells?
Conducting nerve impulses
Supporting neurons during embryonic development
Supplying nutrients
Consuming foreign particles
Long-term potentiation is
increased sensitivity to an electrical stimulus.
decreased sensitivity to an electrical stimulus.
habituation to a stimulus.
the application of high-frequency electrical stimulation.
In multiple sclerosis the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?
Action potentials move in the opposite direction on the axon.
Action potentials move more slowly along the axon.
Action potentials are entirely negated.
All of the above occurs in multiple sclerosis.
A newborn baby dies soon after birth because her diaphragm and rib cage muscles failed to contract and she was unable to breathe on her own. Examination of the baby’s DNA revealed that she had a genetic mutation in a gene that encoded a calcium-binding protein. Which protein was most likely defective in the
actin
myosin
troponin
tropomyosin
In arthropods, locomotion is accomplished by muscles that work against
each other.
the exoskeleton.
an endoskeleton.
a hydrostatic skeleton.
A muscle fiber contracts by a sequence of events initiated by the binding of acetylcholine to its receptor. Which of the following is the correct sequence?
I-The calcium-troponin complex pulls tropomyosin away from the myosin binding sites of actin.
II-The freed-sites of actin bind to myosin to form cross bridges.
III-Calcium ion binds to the troponin.
II, III, and I
III, II, and I
III, I, and II
I, III, and II
