Let's say i hypothesize that plants need water in order to grow. i have a pack of pumpkin seeds that i wish to use in the experiment. explain in detail how i should conduct a controlled experiment to test my hypothesis.

In order to make a proper experiment and see does the plants, in this case the pumpkin seeds, need water to grow, there's several things that should be done. The pumpkin seeds should be planted in several pots, let's say eight pots. All pots should have the same size. The soil in all eight pots should be the exact same. Every pot should be exposed to the same amount of sunlight. Every pot should have the same temperature, thus they should all be kept in the same conditions. Half of the pots with pumpkin seeds will receive water, while the other half will not receive water at all. Every day checks should be made, and notes taken about each of the pots. If the pumpkin seeds in the pots that receive water grow, and the pumpkin seeds in the pots without any water don't, then we can say that the plants need water for their growth and survival.