IB Biology SL C4.2.4 Food Chains and Food Webs Questions

Food chains and food webs model feeding relationships in communities. A chain shows one pathway; a web connects multiple feeding links. Arrows point in the direction that energy and biomass transfer between organisms. In IB Biology SL C4.2.4, questions ask you to define and construct chains, select valid feeding sequences from a web, and draw web links among named organisms.

Exam points

Describe a food chain as a sequence of feeding relationships from a producer to consumers, and distinguish it from a web that links multiple chains.
Construct or interpret a food chain or web from named organisms, using arrows to show feeding direction and the transfer of energy.

[Maximum number: 2]

The sea snail Nucella ostrina and the sea star Pisaster ochraceus are predators of the mussel Mytilus trossulus. The mussels live on rocks at the edge of the sea and feed on phytoplankton and zooplankton. The zooplankton feed on the phytoplankton.

Nucella ostrina

Pisaster ochraceus

Mytilus trossulus

Groups of 50 mussels were transplanted to an experimental area and protected from predation until the start of the experiment. Researchers then investigated the effect of the predators on the population of the mussels over a period of 60 days.

Figure for Question IB Biology SL C4.2.4 Food Chains and Food Webs Questions question 1 — IB Biology SL

The sea star also eats the sea snails. Construct a food web to show the feeding relationships between these five organisms in the ecosystem.

All question bank results loaded

IB Biology SL C4.2.4 Food Chains and Food Webs Questions question 1