Question 19N.3.HL.TZ0.c
| Date | November 2019 | Marks available | [Maximum mark: 2] | Reference code | 19N.3.HL.TZ0.c |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | State | Question number | c | Adapted from | N/A |
Scientists have constructed systems to reproduce the conditions of natural wetlands. The mesocosms below were used to study nutrient removal from water flowing through.
[Source: © 2013. Silviya Lavrova and Bogdana Koumanova (October 2nd 2013). Nutrients and Organic Matter Removal in a
Vertical-Flow Constructed Wetland, Applied Bioremediation – Active and Passive Approaches, Yogesh B. Patil and
Prakash Rao, IntechOpen, DOI: 10.5772/56245. Available from: https://www.intechopen.com/books/applied-bioremediationactive-
and-passive-approaches/nutrients-and-organic-matter-removal-in-a-vertical-flow-constructed-wetland]
State two variables other than temperature and light that should be controlled in this experiment, in order to discover which system is more effective at removing nutrients from water.
[2]
a. type/number of plants ✔
b. type of soil/substrate ✔
c. pH level ✔
d. initial concentration of nutrients ✔
e. timespan of experiment ✔
f. volume of water/influent
OR
flow rate ✔ Do not accept amount instead of volume.
If more than two variables written, mark only the first two.
