DP Biology (first assessment 2025)
Question 19M.2.HL.TZ1.21a.ii
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.HL.TZ1.21a.ii |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Describe | Question number | a.ii | Adapted from | N/A |
a.ii.
[Maximum mark: 2]
19M.2.HL.TZ1.21a.ii
(a.ii)
Describe briefly how an artificial pacemaker works.
[2]
Markscheme
a. a pacemaker contains a battery and pulse generator
OR
it is connected to the heart by wires/cables ✔
b. it detects that the heart’s natural rhythm is incorrect ✔
c. it sends electrical impulses to correct the heartbeat/it replaces sinoatrial node ✔
d. provide a regular impulse/constant rhythm ✔
Examiners report
A majority of the candidates stated that the pacemaker sends electrical impulses or replaces the SA node, and they achieved 1 mark. Few were able to state that the pacemaker is connected to the heart by wires or that it monitors the heart rate itself.
