Biodiversity can be considered at three different levels. Fig. 5.1, Fig. 5.2 and Fig. 5.3 are images that show these three different levels of biodiversity. [Figure 5.1] [Figure 5.2] [Figure 5.3]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2021). The mark or mark type is shown in brackets.

1. [1] (a) Fig. 5.1: species ;
2. [1] (a) Fig. 5.2: genetic ;
3. [1] (a) Fig. 5.3: habitat / ecosystem ;
4. [1] (b)(i) plants: quadrats;
5. [1] (b)(i) plants: transects ;
6. [1] (b)(i) plants: ref. to use, ACFOR / Braun-Blanquet or estimate percentage cover (of species) count species calculate plus species abundance record species density AW species frequency ;
7. [1] (b)(i) insects: pooters / pitfall traps / nets / light traps / sugar traps ;
8. [1] (b)(i) insects: mark-release-recapture ;
9. [1] (b)(i) accept in either section: (identification) keys ;
10. [1] (b)(ii) estimate biodiversity: Simpson's index (of biodiversity);
11. [1] (b)(ii) test relationship: Pearson's linear correlation coefficient / Spearman's rank correlation ;
12. [1] (c) negative: smaller crop area so lower yield;
13. [1] (c) negative: prairie strip insects may feed on crop ;
14. [1] (c) negative: (so) less, profit / income ; must be linked to mp1 or mp2
15. [1] (c) positive: (soil) more fertile / described, so higher yield ;
16. [1] (c) positive: less/no, fertiliser / phosphorus compounds / nitrogen compounds, used; ignore minerals
17. [1] (c) positive: (so) more, profit / income or reduction in expenses ; must be linked to mp4 or mp5