Nervous Coordination (Chapter No.17) - MCQs Biology Book Two (English) - Class 2nd Year (XII or 12th) Science Group

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Chapter No.17
Nervous Coordination

Multiple Choice Questions

1. Encircle the correct choice:
i) Most of the neurons in the human brain are:
a) Sensory neurons
b) Motor neurons
c) Interneurons ✔
d) Auditory neurons

ii) A nervous system can alter activities in its target cells in muscles and gland because:
a) They are electrically coupled by gap junctions.
b) The target cells have receptor proteins for signal released by the nervous system. ✔
c) The nervous system releases signals into the blood to control the target cells.
d) The target cells that become disconnected from the nervous system rapidly die.

iii) For a neuron with an initial membrane potential at -70mv, an increase in the movement of potassium ions out of that neuron’s cytoplasm would result in:
a) Depolarization of the neuron
b) Hyperpolarization of neuron ✔
c) The replacement of potassium ions with sodium ions.
d) The replacement of potassium ions with calcium ions.

iv) Action potentials move along axons.
a) More slowly in axons of large than in small diameter.
b) The direct action of acetylcholine on the axon membrane.
c) Activating the sodium-potassium pump at each point along the axon membrane.
d) More rapidly in myelinated than in non-myelinated axons. ✔

v) The surface on a neuron that discharges vesicles is the:
a) Dendrite
b) Axon hillock
c) Presynaptic membrane ✔
d) Postsynaptic membrane

vi) An inhibitory postsynaptic potential occurs in a membrane made more permeable to:
a) Potassium ions ✔
b) Sodium ions
c) Calcium ions
d) ATP

vii) The major inhibitory neurotransmitter of the brain is:
a) Acetylcholine
b) Epinephrine
c) GABA ✔
d) Endorphin

viii) Where are neurotransmitter receptors located:
a) On the nuclear membrane
b) In the myelin sheath
c) At nodes of Ranvier
d) On the postsynaptic membrane ✔

ix) Which selection is incorrectly paired?
a) Forebrain ⟶ Diencephalon
b) Forebrain ⟶ Cerebrum
c) Midbrain ⟶Brainstem
d) Midbrain ⟶ Cerebellum ✔

x) Which of the following receptors is incorrectly paired with the type of energy is transduces?
a) Mechanoreceptors ⟶ Sound
b) Pain receptors — Electricity ✔
c) Chemoreceptors ⟶ Solute concentration
d) Thermoreceptors ⟶ Heat

Important Points To Remember:

• Nervous co-ordination mainly comprises on highly specialized cells, called neurons.
• All receptors are transducers that convert signals from one form to another form.
• Schwan cells produce myelin in peripheral nervous system (PNS).
• Oligodendrocytes produce myelin in central nervous system (CNS).
• Nerve impulse is an electrical signal that depends on the flow of ions across the membrane of a neuron.
• The voltage measured across the plasma membrane is called membrane potential and it is typically in the range from -50mv to -100mv in an animal cell.
• Action potential is a sudden reversal of the electrical charge across the membrane, triggered by a temporary, localized increase in its permeability to sodium.
• Depolarization makes the membrane potential less negative.
• Hyperpolarization makes the membrane potential more negative.
• The level of depolarization needed to produce an action potential is called threshold potential. 
• Velocity of conduction is greater if the diameter of the axon is larger or if the axon is myelinated. 
• Synapse is junction that control communication between a neuron and another cell. 
• The movement of impulse across the synapse is called a synaptic transmission.
• Electrical synapse involves direct cytoplasmic connections formed by gap junctions between the presynaptic neuron and postsynaptic neurons. 
• Biogenic amines are neurotransmitters derived from amino acids most commonly function as transmitters within the CNS.
• Human nervous system consists of central nervous system and peripheral nervous system.
• Central nervous system is integrating portion of the nervous system.
• CNS stands for central nervous system.
• PNS stands for peripheral nervous system.
• RMP stands for resting membrane potential.
• AMP stands for action membrane potential.
• EPSP stands for excitatory postsynaptic potential.
• IPSP stands for inhibitory postsynaptic potential.
• GABA stands for gamma aminobutyric acid.
• CSF stands for cerebrospinal fluid.
• EEG stands for Electro encephalo gram.
• CT stands for Computed tomography.
• MRI stands for Magnetic resonance imaging.