| Date | November 2012 | Marks available | 1 | Reference code | 12N.3.HL.TZ0.11 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Define | Question number | 11 | Adapted from | N/A |
Question
Define the term biomagnification.
Define the term biomass.
Describe one technique used to estimate the population size of mice.
Markscheme
Process by which chemical substances become more concentrated at each trophic level.
total dry mass of organic matter in organisms/trophic level
(mice are) are captured marked and released (in first cycle);
(mice are) are recaptured and number of marked ones recorded (in second cycle);
population size
(accept other symbols)
Examiners report
Many correct definitions were given, but there were also many answers with missing elements.
Many correct definitions were given, but there were also many answers with missing elements.
They could also describe a technique to estimate the population of mice, but some answers lacked important elements of the process, mentioned quadrats or used the whole population instead of a sample.
