Edexcel IGCSEBiologyGeneral Applications8 Marks

The diagram shows a food web from a grassland ecosystem.

(a)(i)Name a producer in this food web. [Figure 2][1]
(a)(ii)Name a secondary consumer in this food web. [Figure 2][1]
(b)State the trophic level of the hawk in this food web. [Figure 2][1]
(c)If the population of mice were to decrease significantly, suggest two possible effects on other organisms in this food web.[3]
(d)Explain why energy transfer between trophic levels is inefficient.[2]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

Mark scheme

Marking points from the official mark scheme. The mark or mark type is shown in brackets.

15(a)(i) B1: grass / plants (1)
15(a)(ii) B1: frog / hawk / snake / owl (depends on specific food web, assuming hawk eats primary consumer) (1)
15(b) B1: tertiary consumer / fourth trophic level (if hawk eats secondary consumer) (1)
15(c) M1: (e.g.,) owl population decreases (1)
M1: due to lack of food / mice (1)
A1: (e.g.,) snake population increases (1)
M1: due to reduced predation (from owls that would also eat mice) (1)
M1: grass population increases (1)
A1: due to fewer mice (herbivores) (1)
15(d) M1: energy lost as heat (during respiration) / not all parts of organism eaten (1)
A1: energy lost in waste products / excretion / movement (1)

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