| Date | May 2011 | Marks available | 6 | Reference code | 11M.3.HL.TZ2.6 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Explain | Question number | 6 | Adapted from | N/A |
Question
Explain the effects of cocaine in terms of its action at synapses in the brain and its social consequences.
Markscheme
excitatory (psychoactive) drug;
cocaine attaches to dopamine pumps/transporters (on presynaptic membrane);
blocks uptake/recycling / causes dopamine to persist in the synaptic cleft;
amplifies synaptic transmission / causes constant stimulation of postsynaptic neuron;
causes euphoria/feelings of happiness/pleasurable effects;
causes feelings of great energy/alertness/talkativeness;
addictive / causes addiction;
changes in personality / problems with family/friends/work;
crimes to pay for cost of drug/crime associated with the production/distribution;
Examiners report
Some concerns were expressed by teachers about this question. The IB Biology programme stipulates that the effects of cocaine on synapses in the brain and on mood and behaviour should be studied. An Aim 8 suggestion is to look also at the wider consequences for society. A maximum of two marks was awarded for these consequences and even when candidates did not include them, they were able to find six other relevant points if they were well prepared. There was some misinformation about the precise reasons for cocaine causing accumulation of dopamine in synapses, with candidates suggesting that secretion of dopamine increasing rather than reabsorption into the pre-synaptic neuron being prevented.
