Activity 3. Direction: Read the following research problems carefully and identify the Dependent, Independent and Control Variables. Write your answer under the right column. Write your answer on another sheet of paper.
Problem
1. Sassy, a grade 7 student, conducted an activity about how household detergent affects plant growth. She placed the same kind of plants in three separate pots (Pots A, B, C) with the same kind of soil. On pot A, she applied 1 scoop of detergent in one gallon of water in pot A, 2 scoops of detergent in one gallon of water in pot B, and only water in pot C.
2. Harry bought two identical aquariums, labelled as A and B, each containing the same kind, number and size of fish. The amount of water, light and air were the same for both. He fed the fish in aquarium A with commercial fish pellets while home-made fish pellets in aquarium B. The next day, all the fish in aquarium B died while in aquarium A remain alive.
3. Maria wanted to find out which of the two brands of bleach, A or B, is more effective in removing coffee stain from white shirt. She made mixtures of the two bleaches with the same amount of water and soaked white shirts with the same size of stain into each mixture for two minutes. After soaking, she measured the size of the stain left on each shirt.
4. Casey wanted to investigate how sunlight affects the growth of plants. She had two mongo bean plants, A and B. She put plant A beside the window where there is adequate sunlight and put plant B under the table where it sunlight cannot reach. She gave the same amount of water and fertilizer on both plants. After one week, she measured the length of the stem of each plant.