1. Lacey wanted to determine the affect of salt in the diet of cattle
Lacey wanted to determine the affect of salt in the diet of cattle. She set up 10 feed troughs each with differing amounts of salt. She counted the number of cows that fed from each trough throughout the day for one month. What is the independent variable?

2. Lacey wanted to determine the affect of salt in the diet of cattle
Lacey wanted to determine the affect of salt in the diet of cattle. She set up 10 feed troughs each with differing amounts of salt. She counted the number of cows that fed from each trough throughout the day for one month. What is the dependent variable?

3. Roger wanted to determine the best amount of fertilizer to give his tomato plants. He gave 1g, 2g, 3g, 4g, and 5g to groups of plants. What would be needed as a control group for this experiment?

4. Lacey wanted to determine the affect of salt in the diet of cattle
Lacey wanted to determine the affect of salt in the diet of cattle. She set up 10 feed troughs each with differing amounts of salt. She counted the number of cows that fed from each trough throughout the day for one month. Which hypothesis is Lacey most likely studying?
a) If the amount of food given to cows is increased then more cows will feed from that trough.
If the amount of salt given to cows is increased then, the cows will produce more offspring.
c) If the amount of water in a trough is increased then more cows will go to that trough.
d) If the amount of salt in a trough is increased then fewer cows will feed from that trough.

5. A biology class wanted to know how the amount of nitrogen present in soil effected flower production in geraniums. They set up the experiment by planting four geraniums, each the same size and with no flowers, in pots with the same type of soil.
What will be changed in each flower pot?
What will they measure?

6. If there is more pollution in an area then, the rain will have a higher pH than in areas with less pollution.
What is the independent variable?
What is the dependent variable?

7. Why is this a line graph?
What is the dependent variable?

8. What was the independent variable?
Which nutrients increased the algae growth the most?

9. Below are the steps a biologist will complete to study the effect of antibiotics on bacterial growth.
1. Let bacteria cultures grow for three days in an incubator.
2. Count the number of living bacterial colonies in each dish.
3. Prepare four petri dishes with the following antibiotics. Dish 1- No antibiotic, Dish 2- amoxicillin, Dish 3- penicillin, and Dish 4- azithromycin.
4. Place dishes in biohazard bag for disposal.
5. Swab live bacteria cultures into each dish.
In what order should the procedure be completed?

10. Sally wanted to know if music caused plants to grow faster
Sally wanted to know if music caused plants to grow faster. She obtained 10 identical daisy plants. She placed 5 of them in a green house where classical music played 24 hours a day and 5 in a green house with no music. She gave the plants the same amount of light, water and nutrients. The plants also kept at the same temperature. She measured the increase in plant height each day for a month.
Independent variable: ________________________________________________
Dependent variable: _________________________________________________
What is a testable hypothesis for Sally’s experiment on the effect of music on growing plants?
(a) If plants are placed in greenhouses with higher temperatures then, they will grow at a faster rate then those in cooler temperatures.
(b) If the growth rate of plants is influenced by music then, the plants receiving music will increase height at a faster rate than those not receiving music.
(c) If the growth rate of plants is influenced by nutrients then, the plants receiving the most nutrients will have the greatest height.
(d) If the amount of water provided to plants is changed then, those receiving the most water will grow more.

11. A botanist wanted to know how different types of water effected plant growth. He set up testing plots in a greenhouse. Sets of five plants were given one type of water. The normal water for the plants was tap water, the changed waters were mineral, carbonated, rain, distilled, and filtered. He watered each plant with 100 mL of the water each day and right after watering he measured the height of each plant.
What is the independent variable?
What is the dependent variable?
What is the control group?
What is/are the experimental group(s)?

12. A race car driver wants to know how speed affects stopping distance
A race car driver wants to know how speed affects stopping distance. He sets up a mile track and drives the track at 50, 70, 90, 110, 130 and 150 km/h. During each trial he reaches and maintains testing speed and at the end of the mile he brakes at the same spot. He then records the distance it takes to stop.
What is being changed?
What is being measured?
What are some of the control variables that will ensure accuracy in the experiment?

13. At what time are the beetles most active?
Approximately how many beetles are active at 9 A.M.?
The data for this graph was collected in late June. Based on the graph the beetle are most active when
a. the area is free from predators b. it is cool with a little sunlight
c. in the hottest part of the day d. it is dark

14. A biologist was studying how temperature changes affected the number of tulip flowers growing in the spring Correctly label the graph below with the independent and dependent variables from the experiment.

15. Write a hypothesis for the experiment below.
Bait shop Billy wanted to know if he would catch more catfish if he fished with fresh cut shad or frozen shad. He fished in the same spot on Lake Hudson everyday for ten days. For the first five days he fished using only fresh cut shad, for the last five days he fished using only frozen shad. At the end of each day he counted the total number of fish caught.

16. Write a hypothesis for the experiment below.
Roger wanted to know how the pressure in his tires affected his gas mileage. He inflated the tires
on his car to 32 psi and drove for 100 miles. He then repeated the 100 mile drive with his tires
inflated to only 28 psi. He then calculated the gas mileage for each test run.

17. Do you usually measure the mass or volume of a liquid?
Do you usually measure the mass or volume of a gas?
Do you usually measure the mass or volume of a solid?

18. Circle which is larger in each of the groups below.
milliliter (mL) or liter (L)
centimeter (cm) or micrometer (µm)
kilogram (kg) or gram (g)
cubic meter (m³) or cubic micrometer (µm³)

19. A testable statement (always in the “If this is changed then, this will happen” format) about the outcome of an experiment is known as a(n)

20. Write a testable hypothesis for the experiment.
James and Mary were testing the temperature preference of Luna moth larva for cocooning. They set up the two sided testing chamber shown below and placed 20 larva in the chamber. The testing chambers had sticks in them for the larva to cocoon on. After the larva were acclimated and cocooned they recorded their results.
Write a testable hypothesis for the experiment.

21. Place the variables in the correct place. Ray is graphing the data he
Place the variables in the correct place. Ray is graphing the data he gathered during an experiment on fly larva. His data table is below:
Time (hour)
Number of larva present 2 12 4 53 6 78

22. What type of graph would Ray make to display the data below? Why?
Time (hour)
Number of larva present 2 12 4 53 6 78

23. Richard wants to run an experiment to test the effectiveness of red chili powder on deterring caterpillars from eating his tomato plants. Twenty tomato plants from the same package of seed are planted in the same garden. When mature he dusts half of them with red chili powder every week for the entire growing season. Every day he counts the number of caterpillars on each plant and records these numbers in a data table.
what is the independent variable in Richard’s experiment?
what is the dependent variable in Richard’s experiment?

24. A scientist testing the affects of a chemical on apple yield sprays an orchard with the chemical. A second orchard does not receive the chemical. In the fall, the number of apples harvested from each forest is counted. The orchard sprayed with the chemical yields an average of 60 apples per tree, the other orchard yields an average of 40 apples per tree.
1. What would be the dependent variable?
2. Which of the following is the independent variable in the experiment?

25. A scientist testing the affects of a chemical on apple yield sprays an orchard with the chemical. A second orchard does not receive the chemical. In the fall, the number of apples harvested from each forest is counted. The orchard sprayed with the chemical yields an average of 60 apples per tree, the other orchard yields an average of 40 apples per tree.
Based on the data, what can the scientist conclude about the use of the chemical?
a. the chemical decreased the number of apples produced
b. the chemical increased the number of apples produced
c. the chemical made no difference in the apples produced
d. the chemical made the apples taste bad

26. A recipe calls for 2 liters of water. You add 2000 milliliters
A recipe calls for 2 liters of water. You add 2000 milliliters. Have you put in too much, too little, or the right amount? Explain