ConceptConceptDocsDocuments

Edexcel IGCSE Biology feeding relationships

Use feeding-relationship evidence to read food webs, draw chains or pyramids and calculate energy-transfer efficiency from data.

Syllabus
First assessment 2019
Course
Biology 4BI1

Exam points

  • Read food chains and webs to name producers, consumers and trophic levels.
  • Draw labelled pyramids or chains with organisms in the correct order and arrow direction.
  • Calculate transfer efficiency and explain energy loss through respiration, waste or uneaten parts.

Covered syllabus points

4.6 Trophic levels4.7 Concepts of food chains4.8 Food chains and energy transfer4.9 Ten percent energy transfer

(b) Feeding relationships question 1

[Maximum number: 9]

The diagram shows part of a woodland food web.

Figure for Question (b) Feeding relationships question 1 — Edexcel IGCSE Biology

Question (a)

(a)

Which organism is a primary consumer in this food web?

A

aphid

B

blackbird

C

fox

D

oak tree

[ 1 ]

Question (b)

(b)

This is one food chain from the food web.

 oak tree  ⟶  mouse  ⟶  fox \text { oak tree } \text { ⟶ } \text { mouse } \text { ⟶ } \text { fox }
[ 8 ]

Question (i)

(i)

A student counted 20 mice living around 4 oak trees. There were also 2 foxes in the area.

Draw a labelled pyramid of numbers for this food chain on the grid.
Your pyramid should be drawn to scale.

Figure for Question (i) — Edexcel IGCSE Biology
[ 3 ]

Question (ii)

(ii)

Photosynthesis results in 25000 kJ of energy being transferred to the biomass of the oak trees each year.

Only 8\% of this energy is transferred to the biomass of the 20 mice each year.
Calculate the mean amount of energy transferred to the biomass of one mouse each year.
mean amount of energy = kJ

[ 2 ]

Question (iii)

(iii)

Explain why only 8% of the energy stored in the biomass of the oak trees is used by the mice for growth.

[ 3 ]
All question bank results loaded