10. October, 2017Uncategorized

IV:  the pH of the water

DV:  number of tadpoles surviving after 5 days

Exp. question:  Will the pH of the water affect how many tadpoles are still surviving after 5 days?

Constants:  examples are…same type and age of tadpole, same sex of tadpole, same tank water (except the pH), same type and amount of food provided, same type of tank, same temperature water, same number of tadpoles in each tank at the beginning of the experiment.

Control group:  not all experiments have a control group (look at the definition in your glossary); in this case we can pick 7.0 (neutral pH for water) as the control group.

Experimental groups:  tanks with the pH of 8, 7.5, 6.5, 6 and 5.5

Detailed Conclusion Example:

Will the pH of the water affect how many tadpoles are still surviving after 5 days? The number of surviving tadpoles per each pH level was significantly different as the pH moved away from 6.5. The highest number of surviving tadpoles was 88 at a pH of 6.5 (slightly acidic), followed by 78 surviving at a pH of 7.0. As the pH level increased beyond these two pH measurements, the number of tadpoles surviving rapidly decreased. For example, only 43 remained at a pH of 6.0 and only 69 at a pH of 7.5. This experiment suggests that this species of tadpole is adapted to a specific range of pH levels in their natural habitat.