Question 19M.3.HL.TZ1.6
| Date | May 2019 | Marks available | [Maximum mark: 6] | Reference code | 19M.3.HL.TZ1.6 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Explain, Identify | Question number | 6 | 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]
Identify the structures labelled X and Y in the diagram.
[2]
a. X: pinna ✔
b. Y: auditory/cochlear/acoustic nerve ✔
Not many could identify X “pinna” and used less specific terms instead. More identified Y “auditory nerve” correctly.
Identify the structure in the inner ear that is in contact with the stapes.
[1]
oval window ✔
This question was surprisingly difficult for candidates to answer correctly. While there were many incorrect answers, the most notable ones involved other bones of the middle ear, again revealing that students need to read the questions more carefully, as the question specifically asked about a structure in the inner ear. Of course, this could also mean that students are unclear where the middle ear ends and the inner ear begins.
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).