DP Biology (last assessment 2024)
Question 17N.3.SL.TZ0.12
| Date | November 2017 | Marks available | [Maximum mark: 4] | Reference code | 17N.3.SL.TZ0.12 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Calculate, Explain, Outline | Question number | 12 | Adapted from | N/A |
12.
[Maximum mark: 4]
17N.3.SL.TZ0.12
(a)
Calculate the energy loss due to respiration in primary consumers in kJ m–2 y–1.
[1]
Markscheme
190
(b)
Outline why a year is more suitable than a month for the measurement of energy flow.
[1]
Markscheme
accounts for different productivity at different times of year/seasonal variations
OR
more data collected
OR
to increase reliability
OR
trends over time more easily detected
(c)
Explain how pesticides may undergo biomagnification in the lake.
[2]
Markscheme
a. the increase in concentration of the pesticide at higher trophic levels
b. taken in by organisms low in the food chain
c. cannot be excreted so remains in tissues
OR
accumulates as more organisms from lower levels are eaten
d. pesticides do not degrade/degrade very slowly
[Max 2 Marks]
