Question 19M.3.HL.TZ1.6c
Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.3.HL.TZ1.6c |
Level | HL | Paper | 3 | Time zone | TZ1 |
Command term | Explain | Question number | c | Adapted from | N/A |
The diagram shows the human ear.
[Source: Didier Descouens, https://commons.wikimedia.org/wiki/Category:Human_middle_ear#/media/File:Place-desosselets-
Schema.jpg, licensed under CC BY-SA 3.0]
Explain the function of the semicircular canals.
[3]
a. semi-circular canals are concerned with balance/head movement ✔
b. movement of the head causes fluid/liquid/endolymph in the canals to move ✔
c. hair cells detect this movement and transmit information to brain ✔
d. along the vestibular nerve ✔
e. three canals allow us to detect movement in all directions/planes ✔
Students who knew that semicircular canals are involved in balance tended to score 2 or 3 marks here, with weaker students scoring 0 marks because they wrote about hearing. Stronger students distinguished themselves by using appropriate terminology about hair cells (rather than hair).

