Two amino acids are bonded together to form a dipeptide
Which of the following is a synthesis reaction?
If a mRNA molecule is 1800 nucleotides (bases) in length, this molecule will contain _____ codons
Fatty acid B is saturated
Fatty acid A has 10 double covalent bonds scattered throughout its carbon chain while fatty acid B has only single covalent bonds between the carbons in its chain.
Which of the following cell organelles would be most important in secretory epithelial cells?
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum
Which of the following represents the correct order of the layers of the epidermis from the deepest to the most superficial?
2, 3, 1, 4
List the following structures in order from smallest to largest. (1) muscle fiber (2) myofilament (3) myofibril (4) muscle fasciculus
5, 3, 2, 4, 1
Arrange the events of synaptic transmission in correct sequence. (1) sodium ions diffuse into the cell and cause a local potential (2) neurotransmitter binds with receptor on postsynaptic cell (3) neurotransmitter diffuses across the synaptic cleft (4) membrane permeability to sodium ions on postsynaptic cell increases (5) action potential causes release of neurotransmitter
voltage-gated ion channels
Channels that open or close in response to changes in the electrical charge or voltage across the plasma membrane are called
continuous stimulation of the postsynaptic membrane
Lack of acetylcholinesterase in the synaptic cleft would result in
1, 3, 4, 2, 5
Arrange the following list of biochemical events in the correct sequence. (1) An action potential is conducted deep into the muscle fiber by the T tubule. (2) Calcium ions bind to troponin. (3) The membranes of the sarcoplasmic reticulum become more permeable to calcium ions. (4) Calcium ions diffuse into the sarcoplasm around the myofibril. (5) The troponin-tropomyosin complex moves exposing active sites.
a single muscle fiber and a single motor unit
Which of the following will respond to a threshold stimulus with an all-or-none contraction?
A condition in which stimuli occur so rapidly that there are no intervening relaxations between contractions is called
depletion of ATP reserves
Which of the following would contribute to muscular fatigue in the muscle fiber?
Schwann cells form a myelin sheath around only one axon, while oligodendrocytes extend processes to surround several axons at once.
Schwann cells differ from oligodendrocytes in which of the following ways?
inability of the muscle fiber to respond to nervous stimulation
Curare blocks acetylcholine receptors at the motor end plate. This would result in
conveys action potentials to the CNS
The sensory (afferent) division of the peripheral nervous system
Multiple sclerosis is a neurological disorder in which myelin sheaths in the CNS are destroyed. Which of the following neuroglial cells is being damaged in multiple sclerosis?
Mr. Miller has been hospitalized for the flu. The flu virus increases membrane permeability to potassium. You would expect his cells to
A nerve, which causes the smooth muscle of a blood vessel wall to constrict, contains __________ neurons
3, 1, 4, 2
Arrange the following in correct sequence:
(1) autonomic ganglia and ganglionic synapse
(2) synapse with target tissues
(3) preganglionic neuron
(4) postganglionic neuron
short postganglionic axons near the organs they innervate
The parasympathetic nervous system is characterized by
parasympathetic blocking agent
Atropine causes the pupil of the eye to dilate by blocking the effect of muscarinic receptors. This means atropine is a(n)
increased parasympathetic responses and increased sympathetic responses
When a person consumes a substantial amount of nicotine, the response is
muscarinic blocking agent
Acetylcholine will cause the pupil of the eye to constrict. A drug acts on receptors for acetylcholine to cause the pupils of the eye to dilate. Nicotine does not bind to receptors in smooth muscle cells of the iris. Therefore, the drug which causes the pupils to dilate is a
epinephrine and norepinephrine
Sympathetic stimulation of the postganglionic cells of the adrenal medulla causes the release of
spatial summation occurs
When two action potentials arrive simultaneously at two different presynaptic terminals that synapse with the same postsynaptic neuron
cutaneous sensations on the opposite side of the body below the level of injury
Lesions on one side of the spinal cord cut the lateral spinothalamic tract of the anterolateral system and eliminate