Understanding Experimental Design Concepts

In an experiment to test the effect of sunlight on Shrek's swamp plants, what is the hypothesis?

• Swamp plants need water to grow.

• Swamp plants exposed to more sunlight will grow taller.

• Swamp plants grow better in soil than in sand.

• Swamp plants need carbon dioxide for photosynthesis.

Answer explanation

The hypothesis directly relates to the experiment's focus on sunlight's effect. The correct choice states that swamp plants exposed to more sunlight will grow taller, making it a clear, testable prediction.

What is the independent variable in the experiment where the effect of sunlight on Shrek's swamp plants is tested?

• The amount of water given to the swamp plants.

• The type of soil used in the swamp.

• The amount of sunlight the swamp plants receive.

• The height of the swamp plants.

Answer explanation

The independent variable is the factor that is changed in an experiment. In this case, the amount of sunlight the swamp plants receive is being tested to see its effect on the plants, making it the independent variable.

What is the dependent variable in the experiment where the effect of sunlight on Shrek's swamp plants is tested?

• The amount of water given to the swamp plants.

• The type of soil used in the swamp.

• The amount of sunlight the swamp plants receive.

• The height of the swamp plants.

Answer explanation

In this experiment, the dependent variable is what is measured to assess the effect of sunlight. The height of the swamp plants is the outcome that changes based on the amount of sunlight they receive, making it the correct choice.

In the experiment to test the effect of sunlight on the growth of Shrek's swamp plants, what would be the control group?

• Plants that receive no sunlight.

• Plants that receive 4 hours of sunlight.

• Plants that receive 8 hours of sunlight.

• Plants that receive 12 hours of sunlight.

Answer explanation

The control group in an experiment is the one that does not receive the treatment being tested. In this case, plants that receive no sunlight serve as the control group to compare the effects of varying sunlight exposure on growth.

In Shrek's swamp, to test the effect of sunlight on the growth of magical plants, what would be the experimental group?

• Plants that receive no sunlight.

• Plants that receive 4, 8, and 12 hours of sunlight.

• Plants that receive only water.

• Plants that are kept in the dark.

Answer explanation

The experimental group consists of plants that receive varying amounts of sunlight (4, 8, and 12 hours) to observe its effect on growth, while the other options either lack sunlight or do not test sunlight's impact.

What are constants in the experiment to test the effect of sunlight on Shrek's swamp plants?

• The amount of sunlight each plant receives.

• The type of plant, the amount of water, and the type of soil used.

• The height of the plants.

• The growth rate of the plants.

Answer explanation

In the experiment, constants are factors that must remain unchanged to ensure valid results. The type of plant, amount of water, and type of soil used must be controlled, while sunlight is the variable being tested.

Why is it important for Shrek to have a control group in his swamp experiment?

• To ensure that the experiment is conducted in a controlled environment.

• To compare the results of the experimental group with a baseline.

• To increase the number of variables in the experiment.

• To ensure that all plants receive the same amount of sunlight.

Answer explanation

A control group is essential for comparison, allowing Shrek to measure the effects of his experimental conditions against a baseline. This helps determine if the changes observed are due to the experiment itself.

Which of the following is an example of a hypothesis in Shrek's swamp?

• The plant in the control group will not grow in Shrek's swamp.

• If plants in Shrek's swamp are given more sunlight, then they will grow taller.

• The type of soil in Shrek's swamp affects plant growth.

• Plants in Shrek's swamp need water to survive.

Answer explanation

The correct choice is a hypothesis because it proposes a testable relationship: more sunlight will lead to taller plants in Shrek's swamp. The other options are statements or observations, not hypotheses.

In Shrek's swamp experiment, why is it important to keep constants the same for all groups?

• To ensure that the experiment is fair and results are due to the independent variable.

• To make the experiment more complex.

• To ensure that the dependent variable changes.

• To increase the number of variables in the experiment.

Answer explanation

Keeping constants the same ensures that any changes in the dependent variable are solely due to the independent variable, making the experiment fair and valid.

In Shrek's swamp, what is the role of the experimental group in an experiment?

• To serve as a baseline for comparison.

• To test the effect of the independent variable.

• To ensure that the experiment is controlled.

• To keep all conditions constant.

Answer explanation

The experimental group is crucial as it tests the effect of the independent variable, allowing researchers to observe changes and draw conclusions about the variable's impact.