Is yeast alive? biology lab help!!!?

curious1

New member
1.Set up four of the test tubes in a test tube rack.

2.Label each tube with a number, 1-4. Test tube 1 will have yeast and warm water. Test tube 2 will have yeast, warm water, and 1tsp of sugar . Test tube 3 will have yeast, warm water, and 1tsp of flour and test tube 4 will have yeast, warm water, and 1tsp of salt.

3.Fill the test tube three quarters of the way up with warm water. Add 1 tsp. of dry yeast a little bit at a time. Mix by putting your hand or thumb over the top of the test tube and shaking it a soon as you put in the yeast. If not, it will get thick and hard to work with.

4.Pour the yeast so that there is an equal amount in each of the four test tubes.

5.Add 1tsp. of sugar to test tube 2.
1tsp. of flour to test tube 3.
1 tsp. of slat to test tube 4.
One substance per test tube.

6.Cover the opening of each test tube with a balloon. Make sure that each of the test tube has a different color balloon so that it is easier to distinguish it.

7.Observe the test tubes and record your observations.
Dependent Variable:
Independent Variable: The amount of sugar, salt, flour, yeast, and water.

what is my dependent and independent varible? and what is my control group?
 
Yes, yeast is a living organism.

Your dependent variable is the amount of "gas" produced by each test tube (from the respiration of the yeast).

Your independent variables are sugar, flour, and salt. These are the things you are testing/changing.

Your control group is yeast and warm water. This is what happens when you don't test/change anything, in relation to the other groups.
 
Yes, yeast is a living organism.

Your dependent variable is the amount of "gas" produced by each test tube (from the respiration of the yeast).

Your independent variables are sugar, flour, and salt. These are the things you are testing/changing.

Your control group is yeast and warm water. This is what happens when you don't test/change anything, in relation to the other groups.
 
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