Task 2

Materials and tools for a working group:

different kinds of seeds (different size, shape, color), soil, water, 3 dcl plastic cups, plastic spoon, tray, sticky paper to mark the cups (or a black, non-washable marker to mark the variable under study on the plastic cups)

In this task, students will examine whether seed size depends on how quickly seeds germinate. Together with the pupils, the teacher recapitulates the findings of the previous task, thus what the seed needs to germinate.

He discusses with the pupils whether they think that the size of the seed can affect the rate of its germination. The task will be to arrange the seeds listed in the worksheets, according to germination rate. If pupils think some of the seeds will germinate the same quickly they mark them with the same number. Before making the predictions, it is suitable that pupils have seeds available, i. so that they can realistically compare their size. The teacher should select those seeds that are of different size (e.g. large bean seeds, small tomato seeds).

Once the predictions have been made, the teacher discusses with pupils, requesting for justification of the predictions. Further, they verify their predictions by using the knowledge of the previous task (to ensure the most suitable conditions). Also in this case it is necessary to plant more seeds of the same kind (not just one).

The teacher should also go through the verification method with the pupils; which means that some seed germinated earlier – e.g. it is enough if a radicle has appeared at the seed. In this case, it would be useful if the seeds were left to lie freely e.g. on cotton. If the seed is covered with soil, the first indicator of germination will be the emerging cotyledon (s) above the soil.

After verifying the predictions, pupils evaluate their findings, compare them with the predictions and draw a conclusion. In addition to seed size, pupils can further explore how and whether the shape or color of the seed influences germination rate.