Experimental Design Project

You have learned how scientists think, and how they use experiments to find the answer to questions. Now it’s your turn to be the scientist! I want to know what makes fruit ripen faster. Your task is to develop a hypothesis about fruit ripening, and then design an experiment to test that hypothesis. You will analyze your results and write up your experiment in a formal lab report.

For this project you will have access to the following materials:

  • Unripe bananas
  • Brown paper bag
  • Clear plastic bag
  • Incubator
  • Refrigerator/freezer
  • Cold water bath
  • Warm water bath
  • Cardboard box
  • Other?

Use the following outline to plan your experiment.

Purpose/ Introduction:The purpose of this experiment is to determine what factors affect ripening speed of fruit. Bananas, as most people know, are yellow when ripe and have a soft yellow flesh that is sweet. They can ripen independently from their plant, as can be seen when you buy a green one and leave it on your counter. Like other fruits, there are factors which influence the speed at which they ripen. A major factor influencing the ripening speed of fruit is the presence of ethylene. Ethylene is a hormone produced by most fruits; it is a colorless gas with the chemical formula H2C=CH2 (the carbons are double-bonded). Ethylene is lighter than air, which makes it diffuse rather rapidly. When a fruit is exposed to ethylene, it ripens at speeds faster than it would without. Oxygen is necessary for this reaction as well. Every fruit reacts differently to ethylene; bananas are heavily affected by it, while most berries are not.

Hypothesis: If ______, then ______.

Independent Variable: (the factor that you are testing)

______

Dependent Variable: (the data that you will collect in order to determine results)

______

Experimental Group: ______

Control Group: ___bunch of bananas left on Mrs. James’ desk____

Constants: (things that will be kept the same throughout the experiment)

______

Materials/ Methods: (Give a detailed description of the experiment you will conduct. You should list step by step what you will do in order to complete the experiment. This must be approved by Mrs. James)

Data:(How will you collect data? What will you observe in order to determine how fast the fruit has ripened?)