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Ecosystems, interdependence and field sampling

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Question 36

Table 1 shows the number of different freshwater indicator species found at two sites, Site A and Site B, in a river.

Table 1

Indicator speciesNumber at Site ANumber at Site B
Stonefly nymph461
Mayfly nymph290
Caddis fly larva152
Water louse3538
Bloodworm1452
Sludge worm693

Stonefly nymphs, mayfly nymphs, and caddis fly larvae are organisms used as indicators of clean water.

Calculate the percentage of all organisms sampled at Site A that are clean water indicators. Give your answer to two significant figures.

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Ecosystems, interdependence and field sampling Questions

  1. GCSE
  2. /Biology
  3. /Ecosystems, interdependence and field sampling