Biology teacher Gerdien van der Veer has developed an excellent practical lesson in which pupils create an ecosystem in a jar. It comes with a worksheet and a detailed guide listing all the materials needed. These include a large jar, hydro granules, (organic) potting compost and small plants (fittonia or moss). During and after making their ecosystem (pupils work in pairs), they answer questions such as: ‘The ecosystem contains various organisms. Write down an example of an organism from the ecosystem and list three characteristics of living things.’ Or: ‘Explain why the ecosystem you have made can now remain sealed, without the plant dying, for example. Use at least the terms photosynthesis and respiration in your answer.’ In this way, pupils immediately apply what they have learnt in a practical context. This lesson idea is suitable for vmbo-gt and havo years 3/4, and can be downloaded from the vmbo teaching resource PlantKracht. (Tycho Malmberg)