Science Processes

The control group is

• the usual/normal/regular situation or one that receives no treatment

  the one that receives treatment or gets tested

• all the factors the scientist keeps the same throughout the experiment

• the factor the scientist changes or makes different in an experiment

• the factor the scientist measures in an experiment

Answer explanation

The control group is the usual situation or one that receives no treatment, allowing for comparison with the treatment group. It helps determine the effect of the treatment by providing a baseline.

What is the main purpose of having a control group in an experiment?

• To compare results and determine the effect of the independent variable

• To measure the dependent variable

• To ensure every group gets the same treatment

• To change multiple variables at once

Answer explanation

The main purpose of having a control group is to compare results and determine the effect of the independent variable. It serves as a baseline to assess how the independent variable influences the dependent variable.

Priya is conducting an experiment to see how different amounts of sunlight affect plant growth. The independent (test) variable is the factor that a scientist

• keeps the same.

• makes different or changes.

• measures and records in the data table

Answer explanation

The independent variable is what the scientist makes different or changes in the experiment. In Priya's case, it's the amount of sunlight given to the plants, which she varies to observe its effect on growth.

Tags

NGSS.MS-LS1-5

Which of the following would most likely make an experiment better to ensure accurate results?

• Keep only one thing constant.

• Complete many trials of the experiment.

• Record the results in a private journal and never publish them.

• Change as many variables as possible.

Answer explanation

Completing many trials of the experiment increases reliability and accuracy of results by minimizing the impact of random errors and variability, making it the best choice for ensuring accurate outcomes.

Tags

NGSS.MS-PS2-2

Dana wanted to see if adding salt to her plants’ water would affect the number of leaves the plants grew. She used a different type of salt on two of her plants and used no salt for one plant. She kept the amount of water, sunlight, and soil the same for each plant. After two weeks, she measured the number of leaves each plant grew. What is the control group?

• number of leaves

• plant given no salt

• amount of water

• type of salt

Answer explanation

The control group is the plant given no salt, as it serves as a baseline to compare the effects of salt on the other plants. This allows Dana to see how salt affects leaf growth relative to a plant that receives no salt.

The variable we measure to get our results the:

• Dependent Variable

• Independent Variable

• Constant

Answer explanation

The dependent variable is the one we measure to observe the effects of changes in the independent variable. It provides the results of an experiment, making it the correct choice.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS3-4

The variable we are changing/investigating in an experiment is the:

• Dependent Variable

• Independent Variable

• Constant

Answer explanation

The variable we are changing or investigating in an experiment is called the Independent Variable. It is the factor that is manipulated to observe its effect on the Dependent Variable.

Tags

NGSS.MS-PS2-2

Why do we want to test one variable at a time?

• Because it is hard to setup a data table with more than one

• It keeps the experiment fair and you can see what caused the change

• It is what has always been done

• It makes the results better in an experiment

Answer explanation

Testing one variable at a time ensures that the experiment remains fair and allows us to clearly identify the cause of any changes observed. This clarity is essential for accurate conclusions.

The part of the experiment that remains the same for the control and experimental group.

• constants

• control

• independent

• dependent

Answer explanation

In an experiment, 'constants' refer to the factors that remain unchanged for both the control and experimental groups. This ensures that any observed effects can be attributed to the independent variable, making 'constants' the correct choice.

Tags

NGSS.MS-PS2-2

A student is planning an experiment to find out how the height from which he drops a ball affects how high the ball bounces. The dependent variable is the _____.

• Diameter of the ball

• Force acting on the ball

• Height that the ball bounces

• Height from which the ball is dropped

Answer explanation

The dependent variable is what is measured in an experiment. In this case, it is the height that the ball bounces, as it depends on the height from which the ball is dropped.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5