DP Biology (last assessment 2024)
Question 21M.1.HL.TZ1.40
| Date | May 2021 | Marks available | [Maximum mark: 1] | Reference code | 21M.1.HL.TZ1.40 |
| Level | HL | Paper | 1 | Time zone | TZ1 |
| Command term | Question number | 40 | Adapted from | N/A |
40.
[Maximum mark: 1]
21M.1.HL.TZ1.40
Expansin is a plant protein that loosens connections between cellulose fibres in plant cell walls, allowing growth. In what location would expression of the expansin gene be expected to be increased?
A. On the shaded side of a shoot being exposed to light
B. On the light side of a shoot being exposed to light
C. On the shaded side of a leaf that is transpiring rapidly
D. On the light side of a leaf that is transpiring rapidly
[1]
Markscheme
A
Examiners report
Candidates were not expected to be familiar with the role of expansin in the growth of plant cell walls but they were given the information they needed to deduce the answer to this question, as long as their understanding of phototropism was strong enough.
