DP Biology (last assessment 2024)
Question 18M.3.HL.TZ1.5
| Date | May 2018 | Marks available | [Maximum mark: 3] | Reference code | 18M.3.HL.TZ1.5 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Outline, Suggest | Question number | 5 | Adapted from | N/A |
5.
[Maximum mark: 3]
18M.3.HL.TZ1.5
(b)
The brain requires a large energy input. Suggest one reason for this.
[1]
Markscheme
a. brain cells/neurons carry out large amount of metabolic activity
b. maintenance of resting potential requires energy/ATP
OR
functioning of Na-K pumps requires energy/ATP
(c)
Outline the functional magnetic resonance imaging (fMRI) technique for brain research.
[2]
Markscheme
a. (measures brain activity by) detecting changes associated with blood flow
b. more active parts of brain receive more blood flow
c. activity leads to change in magnetization between oxygen-rich and oxygen-poor blood
d. scans/images are taken while the subject is exposed to a stimulus/activity