DP Biology (last assessment 2024)
Question 20N.3.HL.TZ0.17d
Date | November 2020 | Marks available | [Maximum mark: 3] | Reference code | 20N.3.HL.TZ0.17d |
Level | HL | Paper | 3 | Time zone | TZ0 |
Command term | Construct | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 3]
20N.3.HL.TZ0.17d
(d)
A type of ecosystem in Brazil is tropical rainforest. Construct a Gersmehl diagram on the outline provided, to show flows of nutrients between stores in tropical rainforests.
[3]
Markscheme
Gersmehl diagram showing the following:
a. thick arrow from soil to biomass:
b. thick arrow from litter to soil;
c. thin arrow from biomass to litter;
Examiners report
Most candidates did poorly on this question; some had difficulty drawing arrows in correct directions, and most could not indicate differences in flows using arrow thickness; blank answers were seen.
