CourseCourseConceptConceptDocumentDocument

CAIE IGCSE Biology 19.1 Energy Flow Questions

Practise energy-flow questions by tracing sunlight into producers, following chemical energy through food chains and identifying heat transfer to the environment.

Syllabus
2026–2028
Course
Biology 0610

Exam points

  • state the Sun as the principal energy input to ecosystems and food webs
  • identify light energy entering producers and chemical energy moving between organisms
  • trace heat loss and energy transfer from living organisms to the environment

Covered syllabus points

19.1.1—Sun is the principal source of energy19.1.2—Flow of energy through living

Question 1

[Maximum number: 2]

The dominant grass species in an African grassland ecosystem are star grass and red oat grass.
- Star grass is eaten by antelope species, such as topi and Thomson's gazelle.
- Smaller animals such as mice and grasshoppers feed on red oat grass.
- Topi and Thomson's gazelle are eaten by predators such as cheetahs, lions and serval cats.
- Grasshoppers and mice are eaten by serval cats and tawny eagles.
- Vultures feed on dead mammals.

Fig. 1.1 shows part of the food web for this ecosystem.

Fig. 1.1

Fig. 1.1

Question (a)

(a)

State the principal source of energy for the food web shown in Fig. 1.1.

[ 1 ]

Question (b)

(b)

State what happens to energy when it leaves a food web.

[ 1 ]

Question 2

[Maximum number: 1]

The diagram shows energy flow from the Sun, through a food chain and into the environment.

Figure for Question 2 — CAIE IGCSE Biology

What is the form of energy for each numbered arrow?

stage 1

stage 2

heat

chemical

heat

kinetic

light

chemical

light

kinetic

Question 3

[Maximum number: 1]

The food chain shows how energy is transferred to a human.

 lettuce → snails  → duck → human \text { lettuce → snails } \text { → duck → human }

Where did the energy in the lettuce come from?

A

snails

B

soil

C

the Sun

D

water

All question bank results loaded