PYC1501 Semester 01 2020 - Assignment

Semester 1: Assignment 01 (UN: 795454)

Note: This assignment is compulsory. You must submit this assignment to gain examination
admission.

Please choose the most correct option in each question.

Question 1
Stimulus intensity is to impulse frequency as . . . is to the amplitude of the impulse.
1. a synapse
2. conduction speed
3. intensity of light stimulus
4. diameter of the nerve fibre

Question 2
The contrast between two poles of a neuron is called . . .
1. an action potential
2. potential difference
3. resting membrane potential
4. a postsynaptic potential

Question 3
The electrical charge resulting from the difference between the positive and negative ions outside and
inside the cell membrane results in . . .
1. a threshold
2. the action potential
3 the resting membrane potential
4. the refractory period

Question 4
During the group discussion on myUnisa group site, one student mentions that neurons can send
impulses continuously. This statement is . . .
1. correct, because neurons are never inactive
2. incorrect, because the resting potential must be restored before another impulse can fire
3. incorrect, because impulses cannot be conducted during the absolute refractory period
4. correct, because the refractory period prevents over-stimulation of the nervous system

Question 5
Which term refers to the period whereby no neural impulse can be generated, even with intense
stimulation?
1. Action potential
2. Absolute refractory period