Task 3

Materials and tools for a working group:

any type of plant (each group should have the same species, e.g. tomato), crayons (or camera), ruler

This task aims to explore what the plant needs for its growth. Students also understand the difference between germination and plant growth, respectively that these are two different processes. The teacher first discusses with them the findings of the previous task. They are then asked if they think that the plant will need the same conditions for its growth as for the germination process of its seed.

After the discussion, the pupils write down their predictions, and the teacher also asks them to justify them (by their own experience or prior knowledge). The table indicates the conditions to be examined and also their predictions whether or not the plant will grow under the set conditions. Also in this task, they need to handle only one variable at a time. In this way, the pupils are led to objectively establish the facts. Each pair / group can investigate a different variable (light, water, heat, soil). Pupils measure the height of the plant before influencing (above the table) and after influencing (last column).

Finally, they can also work with these data to evaluate whether any of the investigated conditions had an impact on plant growth. Although only one variable is always changing, pupils should always mark them in the table at each observation.

In order to verify the growth conditions, pupils can use the plants shoots from the previous task or to plant new seeds. It is also important to clarify with pupils before carrying out the verification, what does it mean that some of the conditions are not suitable for the plant. If any of the conditions is not suitable, the plant will gradually fade, or begin to lose leaves, change color, etc.

We advise to take a picture of the plant, or to draw it before influencing and after changing the conditions. It is preferable to leave the plant under changed conditions for an extended period of time (e.g. 5-7 days). The teacher can also encourage pupils to suggest how they can measure the growth of a plant – they can use universal scales (e.g. a ruler) or they can create their own (e.g. using a string).

At the end, the pupils, together with the teacher, evaluate their findings and conclude what they have learned, thus to indicate the most suitable conditions for plant growth. The teacher can further expand the investigation by examining whether the conditions that were most suitable for the plant under study were applicable to each plant, thus whether or not each plant needs the same conditions for grooving.