List two groups of sensory receptors, giving the stimulus each perceives.

Explain the processing of visual stimuli.

mechanoreceptors – pressure;
chemoreceptors – chemical substances/pH;
thermoreceptors – temperature;
photoreceptors – light;
mechanoreceptors/proprioceptors – stretching/pressure;
hydroreceptors – humidity;
Accept other appropriate receptors with a stimulus.

retina/rod/cone cells convert light into impulses;
impulses pass to bipolar cells;
bipolar cells pass impulses to (sensory neurons of) the optic nerve;
at the optic chiasma, impulses cross over to the opposite optic nerve;
impulses continue to the thalamus where optical information is processed;
images form in the visual cortex;

N/A

The candidates found difficulty again with explanation of process. Many candidates were just regurgitating from some text about peripheral vision and not answering the question. Few scored rods/cones converting light to nerve impulses. Many candidates were wrongly stating that light passes through the nerves.