Question 19M.3.HL.TZ2.15c
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.3.HL.TZ2.15c |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | c | Adapted from | N/A |
The image shows a Gersmehl diagram of tropical rainforest.
[Source: © International Baccalaureate Organization 2019]
Explain what this diagram indicates about nutrients in this type of ecosystem.
[3]
a. statement correctly explaining the quantity of nutrients in identified circle/circles ✔
eg most nutrients are stored in biomass/equal quantities of nutrients stored in soil and litter.
b. statement correctly explaining high nutrient flow/transfer of any thick/large arrow ✔
eg high transfer rate of nutrients from soil to biomass.
c. statement correctly explaining low nutrient flow/transfer of any thin arrow ✔
eg low transfer rate of nutrients from litter to the outside/another ecosystem.
d. any statement correctly comparing nutrient storage/flow rates ✔
eg higher nutrient transfer between soil and biomass than between biomass and litter OWTTE.
e. a Gersmehl diagram models «interrelationships between» nutrient stores and flows in an ecosystem ✔
Most candidates could realize that most nutrients were stored in biomass; it was nevertheless more difficult for many to explain and compare nutrient stores and flow rates using size of circles and arrows, although excellent answers were seen.
