Question

Marcus does an experiment to compare the number of microorganisms present in the air in his school classrooms. He chooses class 6 and class 7 to do his experiment. Following are the instructions that the teacher gives Marcus to perform his experiment in class 6. 1. Collect a dish containing agar jelly. 2. Label the base of each dish with the number of classroom you are testing: for example - class 6. 3. Place the dish in the classroom and take off the lid. 4. Keep the dish in the classroom for 24 hours and note the changes. Marcus needs to complete his experiment. He follows the instructions and puts one dish each in class 6 and one in class 7. A variable is something that you can change in an experiment. Usually, you change one variable and keep other variables the same. Which two variables should Marcus keep the same from the list given below? 1. The room where he puts the dish. 2. The type of jelly in the dish. 3. The length of the time he keeps the dish. 4. The type of pen he uses to label each dish.

Answer 1

Answer:

nice question

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