Question 19M.3.HL.TZ1.b
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.3.HL.TZ1.b |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Explain | Question number | b | Adapted from | N/A |
The illustration shows a Gersmehl diagram of the taiga biome.
[Source: adapted from P J Gersmehl]
Explain how the amount of litter in a tropical rainforest would differ from the taiga’s and how this would be represented in a Gersmehl diagram.
[3]
a. the circle would be «relatively» smaller
OR
litter layer is less ✔
b. warmer weather favours the decomposition of litter/results in thicker arrow between litter and soil ✔
c. more rainfall favours the decomposition of litter/results in thicker arrow between litter and soil ✔
d. greater number of saprophytes/decomposers in rain forest ✔
e. nutrients would be stored in biomass/biomass circle would be larger ✔
The answers to this question showed a greater range of content knowledge than the answers to any other question. Students with no knowledge of the topic considered litter in this context to mean trash left by tourists. Weaker students who had studied some ecology assumed litter would be more in tropical rain forest simply because they felt more growth would occur in tropical climates. Medium-range students were able to score 2 marks regarding the size of circles, showing adequate understanding and some analysis. Students with a strong understanding of this topic in ecology commented on the role of decomposers as well.
