Date | May 2015 | Marks available | 2 | Reference code | 15M.3.SL.TZ1.14 |
Level | Standard level | Paper | Paper 3 | Time zone | Time zone 1 |
Command term | Explain | Question number | 14 | Adapted from | N/A |
Question
The diagram above shows the set up similar to that used in Pavlov’s experiments on conditioning in dogs. Describe Pavlov’s experiments on conditioning in dogs.
Salivation is normally a simple reflex. Explain the role of sensory, relay and motor neurons in a simple reflex.
Markscheme
a. smell or sight of food provides the (unconditioned) stimulus at the start of the experiment;
b. salivation at the sight or smell of the food is the (unconditioned) response;
c. bell/other stimulus repeatedly applied just before food;
d. bell/other stimulus provides a (conditioned) stimulus;
e. (conditioned) response is salivation at the bell/other stimulus only;
f. experiment was an example of classical conditioning;
Award [2 max] if the terms stimulus and response are not used.
a. sensory neuron carries signal from sense organ/receptors/nose/eye to CNS;
b. motor neuron carries signal from CNS to effector/muscle/salivary gland;
c. relay neuron carries signal from sensory neuron to motor neuron;
Examiners report
Nearly all candidates had sound knowledge of Pavlov’s experiment, although many did not use the required terms.
There was poor knowledge of the exact functions of neurons.