Question

scenario 2: jackie read that aloe vera promoted healing on burned tissue. she decided to investigate the effect of various amounts of aloe vera on the regeneration of planaria (a type of worm). she bisected the planaria to obtain 10 parts (5 heads and 5 tails) for each experimental group. she applied solutions with 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 under identical conditions. on day 15, jackie observed the regeneration of the planaria parts and categorized development as full, partial, or none. a. what is the independent variable in this scenario? ________ b. what is the dependent variable in this scenario? ______ c. list three specific controlled variables in this scenario: ________

Explanation:

Step1: Identify independent variable

The variable that is being changed or manipulated is the concentration of Aloe - vera.

Step2: Identify dependent variable

The variable that is being measured or observed as a result of the change in the independent variable is the regeneration of Planaria parts.

Step3: Identify controlled variables

Controlled variables are kept the same to ensure only the independent variable affects the dependent variable. Here, the amount of Aloe - vera solution (15 ml), the number of Planaria parts per group (10 parts), and the growth chamber conditions are controlled.

Answer:

a. Concentration of Aloe - vera (0%, 10%, 20%, 30%)
b. Regeneration of Planaria parts (full, partial, none)
c. Amount of Aloe - vera solution (15 ml), number of Planaria parts per group (10 parts), growth chamber conditions