8 ORGANISMS REQUIRE A SUPPLY OF ENERGY AND MATERIALS FOR WHICH THEY OFTEN DEPEND ON, OR COMPETE WITH, OTHER ORGANISMS

Task 2

WORKSHEET

Materials and tools for a working group:

water, transparent plastic containers with lid, soil, plastic spoon, tray, soil, bread, apple, orange, cheese, coin, teaspoon.

The second activity aims to investigate the development of fungi and molds as representatives of microdecomposites. In the beginning, teacher asks the pupils whether they have forgotten food in their bag for more than a few days. The discussion is directed to experience with molding process. Teacher will find out the pupils ideas about mold on food. The aim of the further activity is to find out when (in what conditions) the food (or other objects) becomes moldy.

The task will be to investigate under what environmental conditions molds grow. The teacher first asks the pupils to consider whether mold can be formed on any object. He / she can provide pupils with a table in the worksheet showing the specific items they should think about. Pupils indicate on which of the objects the mold can be formed and on which they think it is not possible. Subsequently, pupils should suggest how to verify their predictions. The teacher leads them to compare the conditions with the ones the plants need to grow.

Similar to the task of examining seed germination or plant growth, the teacher makes sure that only one variable is handled at a time (light, heat, water or soil). Individual objects can be placed in a transparent plastic container so they do not touch each other (approximately the same sized pieces of food are placed into the containers). The container should be than closed and placed in the proposed conditions to verify what the pupils think about molding process.

During a week, pupils observe the objects in the containers and mark their findings. In addition, the teacher can focus on the object on which the mold was formed the first. Finally, the pupils come back to their predictions, and compare them with their findings.

The molds formed can be left in sealed containers for a longer period of time to see what happens to the objects. The teacher discusses with pupils whether molds can be found in nature and if so what is their role. The discussion is directed to decomposers which break down organic matter into inorganic constituents. The teacher explains that important decomposers include bacteria, fungi and some small animals.

In the next task, the pupils try create a compost at the school yard. They should use biodegradable waste that can be recycled, similar to paper. The result of its recycling is the formation of natural fertilizer. However, pupils should be reminded that only vegetable waste should be composted. Once created, they can explore how and whether compost affects plant growth at all.