IB Biology SL 4.2.3 Energy flow through food chains Question Bank
Practise IB Biology SL 4.2.3 by explaining how energy enters and moves through food chains.
- Syllabus
- First assessment 2025
- Course
- Biology SL
- Level
- SL
Practise IB Biology SL 4.2.3 by explaining how energy enters and moves through food chains.
The mass of an individual organism can affect its physiology and feeding ecology. The diagram shows the relative mass of carbon (black) and total wet mass (grey) of a marine crustacean, Calanus hyperboreus and a jellyfish, Bathocyroe fosteri.

Explain how energy enters, flows through and is lost from marine food chains.

a. light energy is converted to chemical energy (in carbon compounds/sugars) by photosynthesis
b. (chemical) energy (in carbon compounds) flows by means of feeding/through food chains/webs
c. only (approximately) 10\% of energy is passed to the next trophic level
d. energy released as heat (by respiration)
e. energy is not recycled
f. after death, energy may remain trapped as undigested detritus/fossils/fossil fuels
3 max