Chapter 1 The Science of Biology

1. Chapter 1 The Science of Biology

2. Chapter 1 Vocabulary – 20 words • Scientific method – series of problem solving procedures that scientists use to learn about evens that occur in natures. • Constant – the factor that remains fixed during an experiment while other variables change. • Technology – application of scientific knowledge to solve human needs; also called applied science. • Accuracy (p. 928) • Precision (p. 928) • Safety symbol (p. 917) • Science • Observation • Inference • Hypothesis • Independent variable • Dependent variable • Control group - (p. 7) + does not receive experimental treatment • Qualitative Data (p. 8) • Quantitative Data (p. 8) • Theory – copy from glossary • Bias • Biology • Metric system (p. 24) • Experiment - (p.7) + tests hypothesis

3. Sections 1 What is Science?Section 2 Science in ContextSection 3 Measurements & Safety (p.24 & 25 only) Standards: 1A.1, 1A.3, 1A.4, 1A.5, 1A.6, 1A.7, 1A.8 Objectives: • State the goals of science • Describe the steps to the scientific method • Convert metric units • Accurately measure volume, length, mass, and temperature • Identify lab equipment

4. What is Science? • Science – an organized way of gathering and analyzing evidence about the natural world • “PROCESS of inquiry that searches for relationships that explain & predict nature”. • Biology – study of life

5. What Science IS and ISN’T Natural World NOT Supernatural Phenomena Orderly & Organized NOT Chaotic Evidence NOT Beliefs or Opinions Objective NOT Bias (preference)

6. Practice: Which are Scientific Questions? • How does the composition of concrete affect its strength? • Which is prettier, a tulip or a rose? • What will happen when a strong acid is poured into a beaker of water? • Do reports of ghost sightings increase around Halloween? • How does the amount of carbon dioxide affect atmospheric temperature? • What is the meaning of life?

7. What do Biologists do? • Study diversity of life • Research diseases • Develop technologies • Technology (applied science) – application of scientific knowledge to solve human needs • Improve agriculture • Preserve environment

8. What do Biologists do?

9. Scientific Method “Scientific Methodology” • Scientific Method – a series of problem-solving procedures that scientists use to learn about events that occur in nature. • 6 Steps

10. Scientific Method

11. Step 1: Problem • Observation – act of noticing using your senses • Observations  Questions  Purpose What do you observe about marsh grass?

12. Step 2: Research 3R’s 3R’s • Research information related to the investigation. • Research should be Reliable, Relevant, Recent • Science journals wiki.answers.com wikipedia.com

13. Why does marsh grow to different heights in different locations?

14. Step 3: Hypothesis • (Inference) logical interpretation of what is already known  hypothesis • Hypothesis – possible explanation of an observation that can be tested. • Reasonable explanation based on research! • Predicts relationship between independent and dependent variable  “cause-effect”

15. Marsh grass growth is limited by available nitrogen in soil

16. Step 4: Experiment • Experiment – tests hypothesis under controlled conditions. • One variable tested at a time • Must be repeatable When are experiments supportable?

17. Step 4: Experiment • Independent Variable - you manipulate (control) and change  “cause” • Dependent Variable - changes due to the independent variable (think results)  “effect” changing the independent variable causes change in the dependent variable

18. Step 4: Experiment D R Y Dependent (y-axis) M I X Independent (x-axis)

19. Step 4: Experiment • Control Group – group used for comparison. • Receives NO experimental treatment. • Constant – factor that remains fixed • STAYS CONSTANT

20. Experiment

21. 1) Practice: Identifying Variables Impact-sensing patches tucked behind the ears of 16 University of Virginia football players counted the head knocks that happened during four types of athletic events. Independent Variable? Dependent Variable? Constants?

22. 2) Practice: Identifying Variables Raising the average temperature of the Earth’s atmosphere will cause the polar ice caps to reduce in size. Independent Variable? Dependent Variable?

23. 3) Practice: Identifying Variables If the sugar concentration increases then the candy bar will taste sweeter. Independent Variable? Dependent Variable?

24. 4) Practice: Identifying Variables Two different rose bushes are grown in a greenhouse for three months. They are given 50 mL of water and receive direct sunlight for 8 hours each day. The number of flowers on each bush is counted at the end of the experiment. Independent Variable? Dependent Variable? Constants?

25. 5) Practice: Identifying Variables One tank of goldfish is fed the normal amount of food once a day, a second tank is fed twice a day, and a third tank four times a day during a six week study. Each tank contained two goldfish and they were all fed from the same source of food. Each morning the fish in each tank were weighed. Independent Variable? Dependent Variable? Constants? Control?

26. 6) Practice: Identifying Variables You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. The plants were all given 100 mL of water at noon each day. After two weeks, the height of each plant was observed. Independent Variable? Dependent Variable? Constants? Control?

27. 7) In a controlled experiment, the variable that is changed to test the hypothesis is called the – • Controlled variable • Responding variable • Dependent variable • Independent variable

28. 8) Sarah designed an experiment to find out which mouthwash was most effective against bacteria. She cut out 4 different circles from a paper towel and soaked each circle in a different mouthwash. She put the circles in a Petri dish covered with bacteria (commonly found in the mouth) for 24 hours. The picture shows the results of this test. What should Sarah do to improve her experiment? • Use the same size paper circles for all mouthwashes. • Use the same type of mouthwash on each paper circle. • Use different kinds of bacteria • Use a smaller Petri dish.

29. 9) What happens to the dependent variable in a controlled experiment? • It changes as the independent variable changes. • It changes as the responding variable changes. • It does not change. • It is supported or disproved.

30. 11) A student wants to conduct an experiment to find out how pulse rates changes as the length of time spent exercising increases. The dependent variable will be _____. • breathing rate • pulse rate • time spent exercising • the kind of exercise

31. 12) A student is planning an experiment to find out how the height from which he drops a ball affects how high the ball bounces. The dependent variable is the ____. • diameter of the ball • force acting on the ball • height that the ball bounces • height from which the ball is dropped

32. 13) A student hypothesized that the amount of sunlight a sunflower plant receives determines the number of sunflower seeds the plant produces. In her experiment, the number of seeds produces is the _____. • dependent variable • independent variable • controlled variable • manipulated variable

33. 14) In a controlled experiment, the independent variable is ____. • the results of the experiment • the variable that stays the same • changed to test the hypothesis • always time

34. 15) In an experiment studying how increasing amounts of acid rain affect life in pond water, which of the following would be the dependent variable? • organisms in rainwater • acid rain and non-acid rain • a mixture of pond water and acid • number of organisms in pond water

35. 16) An experiment for a new asthma medication was set up into two groups. Group one was given the new drug for asthma, while group 2 was given a sugar pill. The sugar pill serves as a ___________. • Control • Dependent Variable • Experimental Variable • Constant

36. 17) The measurable factor in an experiment is known as the: • Control • Independent Variable • Constant • Dependent Variable

37. 18) A student sets up an experiment to see if fertilizer affects the growth of seeds. He sets up 10 total pots. 5 pots will receive a small amount of fertilizer and placed in the sun. The other 5 pots will not receive fertilizer and placed in the shade. All 10 pots will receive the same amount of water, the same number of seeds, and the same type of seeds. He measures the growth every 2 days for two months. What is wrong with his experiment? • More than one variable is being tested. • The student should have a larger number of pots. • There is no way of measuring the outcome. • There is no control set-up.

38. 19) A student has a wagon of a certain mass. He plans to investigate how the acceleration of the wagon changes as the force he exerts on it increases. In his investigation, the independent variable is— • The acceleration of the wagon • The force acting on the wagon • The mass of the wagon • The mass of the student.

39. 20) A scientist plants two rows of corn for experimentation. She puts fertilizer on row 1 but does not put fertilizer on row 2. Both rows receive the same amount of water and light intensity. She checks the growth of the corn over the course of 5 months. What is a constant in this experiment. • Amount of water • Corn without fertilizer • Corn with fertilizer • Plant height

40. Step 5: Analyze Data • Data – information gained from observations. 2 Types: • Qualitative Data – collected using your senses  QUALITY descriptions • Texture, color, shape, sound • Quantitative Data – collected using specific tools of measurement  QUANTITY  # • Mass, length, volume, time

41. Practice: Qualitative Vs. Quantitative Circle Qualitative Data and Underline Quantitative Data. Green 100mL Liquid Weight = 5 lbs Sticky Tastes like watermelon Density is 1.5g/mL Odor smells like eggs

42. Practice: Qualitative Vs. Quantitative Circle Qualitative Data and Underline Quantitative Data. Blue/Green Color Weighs 8 lbs Masterful Brush Strokes Peaceful country scenery Cost $300 Picture is 10” X 14” Smells old and musty With Frame is 14” X 18” Textured brush strokes Surface Area = 140 square inches

43. Step 5: Analyze Data • Take accurate measurements • Computers & Technology • Create graphs/tables • Graphs show relationships between variables

44. Analyze Data – Qualitative & Quantitative 14 in 7 in

45. Graphs • Line graph – continuous quantitative (#) data • Direct variation - both variables increase together or both variables decrease together • Inverse variation – one variable increases & one decreases

46. Graphs • Bar graph – non-continuous data that is categorical (counting) • Circle graph – shows a relationship among parts of a whole (%)

47. Graphs Scatter Plot Pictograph

48. Step 6: Draw Conclusion • Data does not PROVE anything it either supports or does not support the hypothesis • Support – hypothesis accepted  publish findings • Not-support– hypothesis rejected & create new hypothesis • Repeat experiment!

49. What can you conclude about nitrogen concentration?

50. Scientific Method 6 steps