Use the technical passage "The Good, The Bad, The Zebra Mussel" to answer the following:

Researchers believe that zebra mussels are ten times more effective in removing toxic contaminants like PCBs than are native mussels. Which of these experiments would test this hypothesis?

Use the information below to answer the following question.

A student conducts an experiment at home to test the effect of different covers on the melting rate of ice. The student places identical ice cubes on separate trays of known mass. The student covers each tray as shown below.

The trays are placed on the same table. After ten minutes, the student removes the covers, discards the excess water, and calculates the mass of each ice cube.

Which of these is the dependent variable in the experiment?

Use the information below to answer the following question.

A student conducts an experiment at home to test the effect of different covers on the melting rate of ice. The student places identical ice cubes on separate trays of known mass. The student covers each tray as shown below.

The trays are placed on the same table. After ten minutes, the student removes the covers, discards the excess water, and calculates the mass of each ice cube.

Which of these is the control in the experiment?

Use the information and the graph below to answer the following question.

Catalase is an enzyme found in plant and animal cells. Hydrogen peroxide is a harmful substance found in cells. Catalase causes hydrogen peroxide to break down into water and oxygen.

A student conducted an experiment to determine whether plant and animal cells have the same amount of catalase. She used liver and potato tissues in the experiment. The student followed the procedures below.

1. Label two identical test tubes, 1 and 2.
2. Pour 10 milliliters of hydrogen peroxide solution (1% concentration) into each test tube.
3. Add a small piece of liver tissue to Test Tube 1.
4. Add a small piece of potato tissue to Test Tube 2.
5. Collect the oxygen released from each test tube for 25 seconds.
6. Measure and record the volume of oxygen for each test tube.

The graph below shows the results from the experiment.

Which of these factors was not controlled in the experiment?

A group of students conducted an experiment to study the growth of bean plants. They used two pots labeled “A” and “B.” Each pot contained 20 small bean plants of similar height. All the plants were treated alike except for the solution they received. Each day for five days, the plants in Pot A were given 40 milliliters of distilled water, while the plants in Pot B were given 40 milliliters of distilled water containing one gram of fertilizer. The table below shows the average height of the plants in each pot for each day of the experiment.

Which of these is being tested in this experiment?

A student enjoys watching birds. She wants to attract goldfinches to the feeders in her backyard in the winter. She observed goldfinches eating thistle seeds during the summer, but is not sure if that is their favorite food. She planned an experiment to find out their favorite food, and bought three different kinds of seeds: thistle, sunflower, and corn.

• State a possible hypothesis for her experiment.
• Identify the independent and dependent variables in her experiment.
• Describe specific experimental procedures she could use to test her hypothesis.
• Describe the data she should record.
• What data would support her hypothesis?

Write your answer in your Answer Book.

A group of students wants to determine whether a gas is released when glucose is added to a solution of living yeast cells and water. Their experimental setup is shown below.

The students add glucose to a mixture of yeast and water in Flask A. If a gas is released, the test solution in Flask B will turn yellow. The students observe and record the appearance of Flask B at the beginning of the experiment, and again after 24 hours.

• Explain the importance of using a control in the experiment.
• Describe a control for this experiment. Be sure to include the specific parts of the setup.
• Compare the control to the original experimental setup.

Write your answer in your Answer Book.

A group of students conducted an experiment to study the growth of bean plants. An equal number of bean plants of similar size were planted in containers A and B. Each day for five days, Container A received water only, while Container B received an equal amount of weak fertilizer solution. The table below shows the average height of the plants in each container for each day of the experiment.

Which of these is being tested in this experiment?