Nature of Science Review

An independent variable is the part of an experiment that...

• is changed by the experimenter

• is measured after the dependent variable is changed

• is kept constant

• is used as a group for comparison

The X axis is a ___________ line on a graph.

• vertical (going up and down)

• horizontal (going left to right)

The Y axis is a __________ line on a graph.

• vertical (going up and down)

• horizontal (going left to right)

What is a testable question that can be answered by an experiment?

• How many animal species live in Australia?

• Why are birds' bones hollow?

• What type of chewing gum stretches the farthest?

• How fast does the Earth rotate around the sun?

Helen is studying the growth of two different types of plants. She planted two of each type of plant in locations with different levels of sunlight: full sun, partial shade, and full shade. For five weeks, Helen records the number of new leaves on each plant.

Which of the following statements correctly describes the independent and dependent variables in Helen's experiment?

• The independent variable is the kind of plant, and the dependent variable is the amount of sunlight.

• The independent variable is the amount of sunlight, and the dependent variable is the number of new leaves.

• The independent variable is the amount of sunlight, and the dependent variable is the kind of plant.

• The independent variable is the number of new leaves, and the dependent variable is the amount of sunlight.

Angelina set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. Identify the independent variable.

• Distance traveled by the ball
• Height of the ramp
• Mass of the ball
• Who set up the experiment (Ms. S, etc)

Tags

NGSS.MS-PS2-2

Why is it important that scientists share their results AND procedures with other scientists?

• Scientists want to make sure that no one else is doing the same experiment as them.

• So other scientists can repeat the experiment and compare data.

• So other scientists can review the procedures and fix any errors in the method.

• So other scientists can review your data and see if your results are strong enough to become a Law.

Dr. Jenna wanted to find out whether drinking caffeinated soda increases a person's pulse rate.

The pulse rates of two groups of people at rest were measured. Group A was then given caffeinated soda and group B was given caffeine-free soda. One hour after drinking the soda, the pulse rates were measured again.

The participants in the experiment were all the same age, and they were all given the same amount of soda. The dependent variable in this experiment is the _____________.

• type of soda given to each group

• amount of soda given to each group

• pulse rate of each group

• age of participants in each group

Tags

NGSS.MS-PS1-2

Scientific theories are based on

• general assumptions of how systems work.
• mathematical principles that can be proven true.
• large amounts of data collected over time.
• observations from within only one scientific discipline.

Tags

NGSS.MS-LS4-1

A scientific ____________ is a statement that describes what always happens under certain conditions in nature.

• law
• theory
• method
• variable

Tags

NGSS.HS-PS2-1