Scientific Method Review

1. Scientific Method Review Run this PPT show to help you review for your midterm.

2. The PROBLEM of an experiment is in the form of a ____. Question

3. A ______ is an EDUCATED GUESS to the problem of the experiment. Hypothesis

4. The hypothesis is based on background research

5. The ___________ states whether your hypothesis is correct or incorrect. conclusion

6. What would make the results of an experiment carried out by a research team VALID or more RELIAABLE? • The experiment was repeated and the same results were obtained each time. • Use a larger sample size.

7. The ________________does not contain the independent variable. control group

8. What is MEASURED is known as the ______ variable. dependent

9. A new idea that IS TESTED in a scientific experiment is known as the ________. hypothesis

10. The results of one experiment carried out by a research team would be considered valid if 1. the experiment had no control setup2. all the members of the research team came to the same conclusion3. the experiment had more than one variable4. the experiment was repeated and the same results were obtained eachtime

11. Which is the dependent variable in Amelia's experiment? the number of bean plants in each group the amount of water given daily to each plant the height of each bean plant the amount of fertilizer given to each group of bean plants

12. A new idea that is tested in a scientific experiment is known as a(an) theory hypothesis inference observation

13. Which statement about the use of independent variables in controlled experiments is correct? A different independent variable must be used each time an experiment is repeated. The independent variables must involve time. Only one independent variable is used for each experiment. The independent variables state the problem being tested.

14. Why do scientists consider any hypothesis valuable? A hypothesis requires no further investigation. A hypothesis may lead to further investigation even if it is disproved by the experiment. A hypothesis requires no further investigation if it is proved by the experiment. A hypothesis can be used to explain a conclusion even if it is disproved by the experiment.

15. The first step in the scientific method is • to state the problem • experimentation • to state the hypothesis • observation

16. An educated guess to the problem of an experiment is known as a • variable • theory • hypothesis • law

17. When performing an experiment, you are testing the • problem • hypothesis • data • conclusion

18. The hypothesis is based on the • conclusion • dependent variable • data collected • background research

19. Your senses can be used to make a(n) • observation • conclusion • hypothesis • problem

20. Which statement represents an observation? • Does the vitamin supplement affect plant growth? • The plants under blue light grew 10cm more than plants under yellow light. • 60 grams of drug X was administered to group A. The new drug was not administered to group B. • I think the vitamin supplement will help pants grow taller.

21. Which statement represents the problem of an experiment? • Does the vitamin supplement affect plant growth? • The plants under blue light grew 10cm more than plants under yellow light. • 60 grams of drug X was administered to group A. The new drug was not administered to group B. • I think the vitamin supplement will help pants grow taller.

22. Which statement represents a hypothesis? • Does the vitamin supplement affect plant growth? • The plants under blue light grew 10cm more than plants under yellow light. • 60 grams of drug X was administered to group A. The new drug was not administered to group B. • I think the vitamin supplement will help pants grow taller.

23. Beta-carotene supplements have been thought to protect against cancer. A study was conducted with 39,000 women aged 45 and up. Group A received a beta-carotene supplement. Group B did not receive the beta-carotene supplement. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo. Identify the independent variable. Beta-carotene supplement

24. Beta-carotene supplements have been thought to protect against cancer. A study was conducted with 39,000 women aged 45 and up. Group A received a beta-carotene supplement. Group B did not receive the beta-carotene supplement. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo. Identify the dependent variable. Their health

25. Beta-carotene supplements have been thought to protect against cancer. A study was conducted with 39,000 women aged 45 and up. Group A received a beta-carotene supplement. Group B did not receive the beta-carotene supplement. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo. Identify the control group. Group B (did not receive the beta-carotene supplement)

26. Beta-carotene supplements have been thought to protect against cancer. A study was conducted with 39,000 women aged 45 and up. Group A received a beta-carotene supplement. Group B received a placebo. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo. Identify the experimental group. Group A (received the beta-carotene supplement)

27. Beta-carotene supplements have been thought to protect against cancer. A study was conducted with 39,000 women aged 45 and up. Group A received a beta-carotene supplement. Group B did not receive the beta-carotene supplement. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo. Identify 2 constants or controls. Gender (all women) Amount of food eaten Number of women in each group

28. Beta-carotene supplements have been thought to protect against cancer. A study was conducted with 39,000 women aged 45 and up. Group A received a beta-carotene supplement. Group B did not receive the beta-carotene supplement. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo. How can the results of this experiment be made more valid? Repeat the experiment. Use a larger sample size

29. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. Identify the independent variable. Substance Z

30. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. Identify the dependent variable. Plant height (how tall the plant grew)

31. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. Identify the control group. The group that did not receive Substance Z.

32. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. Identify the experimental group. The group that received Substance Z.

33. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. Identify 2 constants or controls. Same species Amount of water Amount of sunlight Temperature

34. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. How can the results of this experiment be made more valid? Repeat the experiment. Use a larger sample size.

35. To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with a growth hormone. After 4 weeks of growth under ideal conditions, the plants were measured again. How would you set up the control group? There should be another group with 6 plants that DO NOT receive water.

36. To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with a growth hormone. After 4 weeks of growth under ideal conditions, the plants were measured again. Identify the independent and dependent variables. Independent variable: Growth hormone Dependent variable: Length of the seedling

37. To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with a growth hormone. After 4 weeks of growth under ideal conditions, the plants were measured again. Identify 2 factors that must be kept constant. The amount of water each plant receives. The temperature the plants were kept. The species of plant used. The amount of soil in each pot.