DP Biology (first assessment 2025)
Question 21M.2.HL.TZ2.1g
| Date | May 2021 | Marks available | [Maximum mark: 3] | Reference code | 21M.2.HL.TZ2.1g |
| Level | HL | Paper | 2 | Time zone | TZ2 |
| Command term | Explain | Question number | g | Adapted from | N/A |
g.
[Maximum mark: 3]
21M.2.HL.TZ2.1g
(g)
Explain how neonicotinoids affect synaptic transmission in insects.
[3]
Markscheme
a. neonicotinoids bind to the (acetylcholine) receptor (in insects) ✔
b. (binding happens) in (cholinergic) synapses/at motor end plate/between motor neuron and muscles ✔
c. neonicotinoids bind irreversibly (to receptors)
OR
(receptors are blocked so) acetylcholine is unable to bind ✔
d. acetylcholinesterase/enzymes cannot break down neonicotinoids ✔
e. (synaptic) transmission prevented ✔
f. (causing) insect paralysis/death ✔
Examiners report
In general, the data analysis question was well attempted by the majority of students.
Those students who had studied synaptic transmission scored well. However, many knew the role of acetylcholine here, but not in Q(1)(e).
