Question

Jackie read that Aloe vera promote healing on burned tissue. She decided to investigate the effect of various amounts of Aloe vera on the regeneration of planaria. She bisected the planaria to obtain 10 parts (5 heads and 5 tails) for each experimental group. She applied concentrations of 0%, 10%, 20%, and 30% Aloe vera to the groups. Fifteen mL of Aloe vera solutions were applied. All planaria were maintained in a growth chamber with identical food, temperature, and humidity. On day 15, Jackie observed the regeneration of the planaria parts and categorized development as full, partial, or none.
What is the hypothesis (if/then statement) for this particular experiment?
What are the dependent variable and the independent variable?
What controls are they using in their experimental setup?
When they performed the experiment, they collected the data shown below:
Percent Aloe Vera Count of Regenerated Planaria
0% 2
10% 5
20% 7
30% 3
Should the hypothesis be supported or rejected based on the experiment? Why

Answer 1

Answer:

Hypothesis: IF Aloe vera is applied, THEN the number of regenerated planaria will increase

Independent variable: The different amounts of Aloe vera applied

Dependent variable: Number of regenerated planaria

Control group: The parts of planaria that received 0% of Aloe vera

Conclusion: The Hypothesis should be rejected

Explanation:

Hypothesis in an experiment is a testable explanation to an observed problem. It aims at proferring a possible solution/answer to a question. In this experiment, the hypothesis will be: IF Aloe vera is applied, THEN the number of regenerated planaria will increase

The independent variable refers to the variable being manipulated or changed in the experiment while the dependent variable is the variable that responds to the changes made to the independent variable. The dependent variable is the measured variable. In this experiment, the independent variable is THE DIFFERENT AMOUNTS OF ALOE VERA APPLIED while the dependent variable is THE NUMBER OF REGENERATED PLANARIA.

The control group of an experiment is the group that differs from the experimental group by not receiving the experimental treatment (independent variable). In this experiment, the control is the PART OF PLANARIA THAT RECEIVES 0% OF ALOE VERA.

Based on the outcome of the experiment, it can be seen that there was an initial increase in number of regenerated planaria but the number later declined, hence, the hypothesis given will be REJECTED as it doesn't explain the declination.