Controlled Experiments, Variables and Graphing PracticeQuiz

What is the independent variable in the following hypothesis?

HYPOTHESIS: If I spend more time studying, then my grades in science will improve.

• Time spent studying

• Improvement in grades

• Playing soft music in the background

• Location for studying science

Ellin is conducting a scientific investigation in which she measures a certain type of plant's growth in response to different amounts of fertilizer. What is the independent variable?

• Amount of fertilizer

• Plant growth

• Type of plant

• Temperature of the fertilizer

Adam conducted a science experiment on the effect of different environments on plant growth. He put one plant in the closet and the other plant in the window at his house. What should Adam measure in this experiment?

• Total Growth of Plant

• Plant Environment

• The Effect of Different Environments

A student performed an experiment that tested how many days it takes different types of grass seed to grow to a height of ten centimeters. Four types of grass seed were tested, and the student recorded the number of days for each type to grow.

What is the student changing in this experiment?

• type of grass seed

• two cm

• number of days

• sunlight

A student wants to test how different amounts of UV light affect the growth of the bacteria, Staphylococcus aureus. She wants to grow the bacteria in petri dishes for her experiment. Which of the following variables should NOT be held constant in this experiment?

• amount of UV light bacteria is exposed to

• amount of time to grow bacteria

• location of petri dishes while growing bacteria

• type of bacteria (Staphylococcus aureus)

A student is investigating how compost can increase the size of vegetables grown in the garden. To test this, two separate gardens will be grown that are almost identical. The only difference will be that one plot will use regular soil and the other will use compost enriched soil. What is the dependent variable in this investigation?

• compost enriched soil

• quality and size of vegetables

• two garden plots

• water supply

Students are testing the James River for dissolved-oxygen levels. They test in the Blue Ridge Mountains, at the river's source, and in Richmond Virginia, a highly populated area. What is the independent variable in this experiment?

• the location of the test sights

• the time of year for gathering samples

• the method for testing dissolved oxygen

• the time of day for gathering samples

The factor that is being measured in an experiment is called the ___.

• dependent variable

• independent variable

• constant

• hypothesis

John and Emily were experimenting with the effects of road salt on plant growth. To do this, they watered plants daily with the same amount of salt water. They could BEST improve their experiment by ___.

• watering half the plants with pure water and half with salt water

• adding food color to see how far the salt penetrates the plants

• cooling the salt water before watering the plants

• increasing the amount of salt added to the water each day

Ellin is conducting a scientific investigation in which she measures a certain type of plant's growth in response to different amounts of fertilizer. What is the dependent variable?

• Plant growth

• Amount of fertilizer

• Type of plants

• Temperature of the fertilizer