SCIENTIFIC METHOD John watches his grandmother bakes bread

SCIENTIFIC METHOD

John watches his grandmother bakes bread. He asks his grandmother what makes the bread rise. She explains that yeast releases a gas as it feeds on sugar. Her grandmother uses 20 g of sugar whenever she bakes. John wonders if the amount of sugar used in the recipe will affect

�Hypothesis: If the amount of sugar is changed then the size of bread loaf changes also. �MV/IV: Amount of Sugar �DV: Size of bread loaf �Constants: Recipe, ingredients, type of oven, temperature, time of baking, kind of pan �Control: 20 g of sugar

if feeding mice a vitamin supplement will make them grow larger. She feeds five mice their regular food and she feeds five other mice food with vitamins. She measures the weight of the mice at the start and end of the experiment.

�Hypothesis: If the mice are given vitamin supplement then they will grow larger/bigger. �MV/IV: Vitamin Supplement �DV: Growth of mice/Weight of mice �Constants: Kind of mice, number of mice, kind & amount of food, size and weight of mice, number of feeding days, time of feeding, measuring device

A student is interested in the effect of the temperature of water in her aquarium on the activity level of her fish. She divides her aquarium water and fish into three aquariums, one that is maintained at room temperature (about 21⁰C), one that is heated to 27 ⁰C, and one that is cooled to 16 ⁰C. At six p. m. each day, she watched the fish for 30 minutes and records her observation about their activity.

�Hypothesis: If the temperature of the water is changed, then the level activity of the fish is affected. �MV/IV: Temperature of water �DV: Activity level of fish �Constants: number of fish, type/size/ weight of fish, size of aquarium, level of water, time of observation, length of time of observation, number of days