Question

Students interested int the development of plants designed an experiment to test germination in different types of seeds. They placed 2 pumpkin seed, 2 radish seeds, and 2
zucchini seeds on damp filter paper in 3 different petri dished and observed the dishes for several weeks. The water on the filet paper was slightly acidic in the pumpkin dish,
neutral in the radish dish, and slightly basic in the zucchini dish. Each dish was kept at a different temperature. After several weeks of data collection, the students had a
difficulty coming to a conclusion.
Using complete sentences, please answer the following questions:
a. What errors did the students make in designing this experimental procedure?
b. How could this procedure be changed to make this experiment valid?

Answer 1

Answer a)

The students should only have changed one variable to test for germination of seeds. They should have just changed the seed types and rest all factors like temp, pH should be kept constant for all of them.

Answer b)

The procedure could be changed as follows. The students should place three of each types of seeds in the petri dish. They should keep all the conditions like nutrients, temperature, pH constant for all the three dishes. After this observations should be made to check which seed germinates faster.