BIO 251 LATEST 2026 STUDY GUIDE QUESTIONS AND
ANSWERS GUARANTEE A+
✔✔Which of the following neurotransmitters is/are classifieds as a catecholamine and
are derived from the amino acid tyrosine? - ✔✔dopamine, norepinephrine and
epinephrine
✔✔The autonomic nervous system regulates the activity of most internal organs. It does
this by controlling all the following tissues that make up those organs EXCEPT_____ -
✔✔Skeletal muscle
✔✔True or False. Both the sympathetic nervous system and parasympathetic nervous
system control the same visceral organs, however, their effects on the organs are
usually opposite. - ✔✔True
✔✔A lower heart rate and an increase in digestion are associated with the activity of
what branch of the nervous system? - ✔✔PNS
✔✔Which of the following statements about the sympathetic nervous system is FALSE?
- ✔✔preganglionic neurons release the neurotransmitter norepinephrine (NE)
✔✔Which of the following statements about the parasympathetic nervous system is
FALSE? - ✔✔postganglionic neurons release the neurotransmitter norepinephrine (NE)
✔✔What is the neurotransmitter released by somatic motor neurons at the
neuromuscular junction? - ✔✔acetylcholine (Ach)
✔✔At the neuromuscular junction, binding of neurotransmitter to______ type receptors
causes depolarization of the muscle cell membrane leading to the generation of action
potentials on the muscle cell. - ✔✔nicotinic cholinergic
✔✔In the sympathetic nervous system, the receptor type for both norepinephrine (NE)
and epinephrine are classified as_______ - ✔✔either a or ß adrenergic receptors
✔✔The somatic nervous system regulates the activity of_____ - ✔✔Skeletal muscle
✔✔Which of the following DOES NOT happen during synaptic transmission at the
neuromuscular junction? - ✔✔A hyperpolarizing graded potential is produced by the
binding of neurotransmitter to its receptor on the muscle cell membrane which inhibits
the muscle cell
✔✔With regard to the somatic nervous system, what is a motor unit? - ✔✔a single
somatic motor neuron and all the muscle cells it controls
, ✔✔True or False. Every action potential that reaches the axon terminal of a somatic
motor 12) - neuron will generate an action potential in a healthy skeletal muscle cell. -
✔✔True
✔✔In the retina, which type of photoreceptor has the highest sensitivity to light and is
used 13) - during dim or low light conditions? - ✔✔Rods
✔✔In the retina, which photoreceptor type is used for high acuity vision, i.e., used to
form highly detailed visual images? - ✔✔Cones
✔✔The amount of light entering the eye is primarily regulated by what structure? -
✔✔Pupil of the iris
✔✔In order to focus light coming from a near source onto the retina, the lens adjusts its
refractive power (ability to bend light) through what process? - ✔✔accommodation
✔✔Which of the following defects in vision is INCORRECTLY matched with its cause? -
✔✔glaucoma: reduced eye fluid volume, and therefore, less eye pressure
✔✔The inner circular smooth muscle layer of the iris of the eye is controlled by
the_______nervous system and its contraction causes pupillary_______ -
✔✔parasympathetic: constriction
✔✔When you are scared, your pupils dilate to let more light enter your eye. Which of
the following statements best explains what causes this to occur? - ✔✔the sympathetic
nervous system is activated, which causes contraction of the outer radial muscle of the
iris and pupillary dilation.
✔✔Which of the following occurs during accommodation for near vision? - ✔✔The lens
becomes rounder, thus bending light waves to a greater extent to focus them onto the
retina
✔✔The ciliary muscle of the eye that controls the shape of the lens to regulate it's ability
to refract (bend) light waves is controlled by which branch of the nervous system? -
✔✔PNS
✔✔In the absence of light, photoreceptors in the retina release a neurotransmitter that
inhibits_______which in turn inhibit ganglion cells of the retina. - ✔✔bipolar cells of the
retina
✔✔When we enter a dark room, the amount of photopigment in
the_________photoreceptors is slowly______
ANSWERS GUARANTEE A+
✔✔Which of the following neurotransmitters is/are classifieds as a catecholamine and
are derived from the amino acid tyrosine? - ✔✔dopamine, norepinephrine and
epinephrine
✔✔The autonomic nervous system regulates the activity of most internal organs. It does
this by controlling all the following tissues that make up those organs EXCEPT_____ -
✔✔Skeletal muscle
✔✔True or False. Both the sympathetic nervous system and parasympathetic nervous
system control the same visceral organs, however, their effects on the organs are
usually opposite. - ✔✔True
✔✔A lower heart rate and an increase in digestion are associated with the activity of
what branch of the nervous system? - ✔✔PNS
✔✔Which of the following statements about the sympathetic nervous system is FALSE?
- ✔✔preganglionic neurons release the neurotransmitter norepinephrine (NE)
✔✔Which of the following statements about the parasympathetic nervous system is
FALSE? - ✔✔postganglionic neurons release the neurotransmitter norepinephrine (NE)
✔✔What is the neurotransmitter released by somatic motor neurons at the
neuromuscular junction? - ✔✔acetylcholine (Ach)
✔✔At the neuromuscular junction, binding of neurotransmitter to______ type receptors
causes depolarization of the muscle cell membrane leading to the generation of action
potentials on the muscle cell. - ✔✔nicotinic cholinergic
✔✔In the sympathetic nervous system, the receptor type for both norepinephrine (NE)
and epinephrine are classified as_______ - ✔✔either a or ß adrenergic receptors
✔✔The somatic nervous system regulates the activity of_____ - ✔✔Skeletal muscle
✔✔Which of the following DOES NOT happen during synaptic transmission at the
neuromuscular junction? - ✔✔A hyperpolarizing graded potential is produced by the
binding of neurotransmitter to its receptor on the muscle cell membrane which inhibits
the muscle cell
✔✔With regard to the somatic nervous system, what is a motor unit? - ✔✔a single
somatic motor neuron and all the muscle cells it controls
, ✔✔True or False. Every action potential that reaches the axon terminal of a somatic
motor 12) - neuron will generate an action potential in a healthy skeletal muscle cell. -
✔✔True
✔✔In the retina, which type of photoreceptor has the highest sensitivity to light and is
used 13) - during dim or low light conditions? - ✔✔Rods
✔✔In the retina, which photoreceptor type is used for high acuity vision, i.e., used to
form highly detailed visual images? - ✔✔Cones
✔✔The amount of light entering the eye is primarily regulated by what structure? -
✔✔Pupil of the iris
✔✔In order to focus light coming from a near source onto the retina, the lens adjusts its
refractive power (ability to bend light) through what process? - ✔✔accommodation
✔✔Which of the following defects in vision is INCORRECTLY matched with its cause? -
✔✔glaucoma: reduced eye fluid volume, and therefore, less eye pressure
✔✔The inner circular smooth muscle layer of the iris of the eye is controlled by
the_______nervous system and its contraction causes pupillary_______ -
✔✔parasympathetic: constriction
✔✔When you are scared, your pupils dilate to let more light enter your eye. Which of
the following statements best explains what causes this to occur? - ✔✔the sympathetic
nervous system is activated, which causes contraction of the outer radial muscle of the
iris and pupillary dilation.
✔✔Which of the following occurs during accommodation for near vision? - ✔✔The lens
becomes rounder, thus bending light waves to a greater extent to focus them onto the
retina
✔✔The ciliary muscle of the eye that controls the shape of the lens to regulate it's ability
to refract (bend) light waves is controlled by which branch of the nervous system? -
✔✔PNS
✔✔In the absence of light, photoreceptors in the retina release a neurotransmitter that
inhibits_______which in turn inhibit ganglion cells of the retina. - ✔✔bipolar cells of the
retina
✔✔When we enter a dark room, the amount of photopigment in
the_________photoreceptors is slowly______
