Controlled Experiments (A)

An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, sunlight, and listens to the same music. In this investigation, the dependent variable is ...

• The type of plant

• Plant Growth

• The type of music
• The type of liquid

Tags

NGSS.MS-LS1-5

50 weightlifters are given vitamin supplements before they lift and 50 different weightlifters are given no supplements and change in muscle mass is recorded after 4 months. Which of the following should be control variables/constants for this experiment? (Check all that are true)

• amount and type of food eaten during day

• % increase in muscle mass

• type of exercise

• being given supplements or not

Look at the chart. What is the control group?

• Usual route

• alternate B

• alternate C

• time in minutes

Tags

NGSS.MS-PS2-2

Water fleas typically live in water that is 20^oC. A student believes that increasing water temperature will increase heart rate. Water fleas are placed in 20°C, 30^oC, 40^oC, and 50^oC water and their heart rates are recorded. Which of the following best describes the control group?

• water flea heart rate

• 20^oC water

• # of water fleas

• 40^oC water

• type of flea

Tags

NGSS.MS-PS3-4

A botanist is curious to know if a carnivorous plant (Venus Fly Trap) grows better with a diet of live flies or dead flies. The plant normally eats live flies. He puts three plants in a terrarium with live flies, and he puts three other plants in a terrarium and feeds the plants dead flies by hand. He measures the plants' growth at the start and end of the experiment. What is the independent variable?

• Dead Flies

• Plants' growth

• Type of Plant

• The terrarium

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

A botanist is curious to know if a carnivorous plant (Venus Fly Trap) grows better with a diet of live flies or dead flies. The plant normally eats live flies. He puts three plants in a terrarium with live flies, and he puts three other plants in a terrarium and feeds the plants dead flies by hand. He measures the plants's growth at the start and end of the experiment. What is the control group?

• Dead Flies

• Plants' growth

• Live Flies

• Three Plants

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

A study was created to test the effects of jazz on people’s sleep patterns. The hypothesis of the experiment was that if people listened to jazz music as they fall asleep, they will sleep for longer periods of time. For the experiment, 2 groups of people were created. One group was placed in a quiet room where they went to sleep and they were timed on how long they slept. The other group was placed in a room where jazz music played softly as they began to sleep and played throughout the night. As each group awoke, their sleep times were monitored. Check all that are control variables/constants?

• Type of Bed they sleep on

• How many people are in each group

• Sleep time

• Room Temperature

A scientist investigates the effect of carbon dioxide on plant height. The scientist grows plants in several closed containers. All the plants receive the same amounts of water and light, but the air in each container has a different amount of carbon dioxide. What is the independent variable in this experiment?

• the amount of carbon dioxide in each container

• the number of plants in each container

• the amount of water provided to the plants

• the height of each plant after a period of time

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Some researchers are developing a new fertilizer designed to improve the growth of plants in hot, dry climates. The fertilizer was applied to one hundred desert plants in a greenhouse. The average daytime temperature in the greenhouse was 90°F, and the humidity levels were low. Which is best for the researchers to do next?

• compare plants that received fertilizer to similar plants that received none

• begin selling the fertilizer to gardeners living in hot, dry climates

• change the conditions in the greenhouse and retest the fertilizer

• test the fertilizer on plants that are adapted to cooler climates

Tags

NGSS.MS-ETS1-3

NGSS.MS-LS2-1

NGSS.MS-LS2-4

An experiment was carried out to determine whether drinking caffeinated soda increases 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. 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

• the type of soda given to each group

• pulse rate of each group

• amount of soda given to each group

• age of the participants in each group