Jackie read that aloe vera plants promoted healing of burned tissues. she decided to investigate the effect of varying amounts of aloe vera on the regeneration (regrowth) of planaria (a small water creature). 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 milliliters 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 purpose of the experiment? how many animals were in each experimental group? in the experiment above, what is the independent variable? in the experiment above, what is the dependent variable? in the experiment above, what are the constants? how did jackie measure the regeneration of the planaria? how could this experiment be improved?