| Date | May 2017 | Marks available | 4 | Reference code | 17M.3.SL.TZ1.7 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Explain | Question number | 7 | Adapted from | N/A |
Question
The diagram shows the anatomy of the human ear.
Label the cochlea on the diagram.
Explain the structure of the semicircular canals in relation to their functions.
Explain the role of ganglion cells in the eye.
Markscheme
a. there are three semi-circular canals set perpendicular to one another /orientated in three planes of space / the direction of movement of the head in any direction is sensed
b. each canal is filled with liquid/perilymph
c. each canal contains «sensory» hairs
d. when the head moves the liquid in the canal moves more slowly/lags behind
e. this causes the sensory hairs to bend
f. send impulses to the brain «via the vestibular nerve»
a. ganglion cells transfer information to the brain
b. they receive visual information from photoreceptors/rod and cone cells/bipolar cells
c. their long axon extends to the brain «in the optic nerve»
d. they detect/process movement/colour
