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?

A student performed an experiment that tested how many days it takes different types of grass seed to grow to a height of two inches. Four types of grass seed were tested, and the student recorded the number of days for each type to grow. Use this information to answer the next question.

What should be held constant in this experiment?

A student is studying the effect of sunlight on plants. The student developed this hypothesis: Plants need light to make food and to grow properly. To conduct a controlled experiment, which method should she use?

What is the independent variable in the following hypothesis?

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

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?

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. He measured the growth of each plant weekly for six weeks. He then created a graph after he reviewed his data. What is the dependent variable of Adam's experiment?

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

What is the independent variable in this experiment?

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?

What is the independent variable in the following hypothesis?

"If the salinity of freshwater is increased, then the growth rate of harmful algae decreases."

Identify the independent variable in the following hypothesis. "If the amount of rainfall increases, then the occurrence of plant disease decreases."

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?

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 ___.

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?

James is conducting an experiment to test the effect of insecticides on frogs. What is the control group in his experiment?

Jackie performs an experiment on how the type of music played in a room can affect plant growth. In her experiment, the independent variable is the ___.

Alicia is testing the effectiveness of different brands of antibacterial hand sanitizers. What is the independent variable in Alicia's experiment?

Jeremiah is measuring the growth of two indoor plants. He wants to find out if there is a difference in plant growth based on the amount of sunlight that each plant receives. All of the following are variables in this experiment EXCEPT ___.

Glenda is designing an experiment for her science fair project on the amount of water that will grow the tallest plant. She wants to find out which amount of water will grow the tallest plant - 100mL, 200mL, or 300mL per week. What is the independent variable in this experiment?

A student is conducting an experiment on the movement of a marble through five different substances. The student knows that is takes an average of 0.9 seconds for a marble to move through 80 mL of water. What is the control in the experiment?

A restaurant chef conducts an experiment in which several small potatoes of the same size are boiled for various amounts of time from 1 minute up to 15 minutes. Which of the following statements could be an aim of the experiment?

Which of the following measurements is correct for the volume of liquid in the measuring cylinder?

Evan ran a series of experiments testing how high different balls bounced. Which of the following is not a good conclusion for his experiments?

Maddie measured how far an elastic band stretched when 50g masses (metal weights) were hung from it. Which of the following is the variable that she is changing (the independent variable)?

Joe noticed that when he washed dishes he sometimes made lots of froth and at other times made almost none. He designed an experiment where he put 1 drop of detergent in the sink and turned the tap on high until the sink was half full. He then repeated the experiment with 2 drops of detergent, then 3 then 4. Identify his dependent variable.