Chapter 1 The science of biology

1. Chapter 1The science of biology

2. 1-1 What is Science? • an organized way of using evidence to learn about the natural world. • also used to describe the body of knowledge built up over the years • Always changing (Pluto, 2006) http://news.nationalgeographic.com/news/2006/08/060824-pluto-planet.html

3. What are the goals of science? • investigateand understand the natural world. • Collect data/ observations • To explain events in the natural world • use those explanations to make useful predictions.

4. Thinking like a scientist… • Observation: the process of gathering information about events or processes in a careful, orderly way.

5. Thinking like a scientist… • Data: the information gathered from observations • Quantitative: involve numbers/measurements • Qualitative: descriptive/ not easily measured • Find patterns/trends

6. Thinking like a scientist… • Inference: a logical interpretation based on prior knowledge or experience (data) • Footprints/fossils • Scientists may use inferences at first but MUST backup with facts

7. Explaining and Interpreting Evidence • Hypothesis: proposed scientific explanation for a set of observations • May be accepted or rejected • Must be able to be tested… • Using controlled experiments and collecting new data • …and re-tested • Validity • Reliability

8. Collaboration • Scientists and researchers often work in teams • Critical analysis/sharing of ideas • Review process helps to ensure valid results

9. Science is always changing • A continuous process involving: • Asking questions • Observing • Making inferences • Testing hypotheses • A good scientist is a skeptic of both new and old ideas • Men vs. women

10. Scientific Thinking • Scientists are trained to use a scientific methods as a guide to make intelligent decisions • However…

11. Other factors involved in decision making • Society/community • Economic considerations • Laws • Morals/ethics • Stem cell research? • Abortion?

12. 5 questions a biologist might ask about:

13. 1-2 How Scientists Work • Ask questions and test them! • Scientific Method • State the problem • Collect information • Form a hypothesis • Design and conduct an experiment • Record observationsand data • Check results/retest • Draw your conclusions • Communicate your results

14. Designing a Controlled Experiment • Variables must be controlled • Dependent/responding variable • Independent/ manipulated variable • Controlled variables • Record results/analyze findings • Draw a conclusion

15. Spontaneous Generation as an Example • Spontaneous generation • What if we wanted to test it? • Francesco Redi’shypothesis (p.9)

16. Repeating Investigations • Anton van Leeuwenhoek- “animalcules” • John Needham challenges Redi • “SG just needs the right conditions” • LazzaroSpallanzani adds his two cents • Boils gravy longer- seals flask • Some argued SG needed air (a “life force”) • Pasteur settles it with his curved flask

17. The Scientific Method: • State the problem • Collect information • Form a hypothesis • Design and conduct an experiment • Record observations and data • Check results/retest • Draw your conclusions • Communicate your results

18. When Experiments Are Not Possible… • Oscar Pistorius Olympic Debate • Field studies • Ethical concerns • If they are careful, scientists are still able to discover reliable patterns to make inferences about

19. So what if your hypothesis is accepted? • Scientific Theory: a well tested explanation that unifies a broad range of observations • a currently acceptable idea- universally accepted to be true • NOT a fact • Scientific Law = fact (ex: gravity)

20. 1-3 Studying Life • bio = “life” • logy = “the study of” • How do we know what is “living” and what is “nonliving”?

21. 8 Characteristics of Living Things 1. All living things are made up of cells • Unicellular • Multicellular

22. 2. All living things reproduce • Sexual • Asexual

23. 3. All living things are based on a universal genetic code • DNA determined the traits you receive from your parents

24. 4. All living things grow and develop • Increase in size • Cell division for specific “parts”

25. 5. All living things obtain and use materials and energy • To grow and develop • To simply stay alive • Metabolism: the breakdown of materials an organism uses to carry out its life processes

26. 6. All living things respond to their environment • Stimulus • External • Internal

27. 7. All living things maintain a stable environment • Homeostasis- internal feedback mechanism • Shivering and sweating

28. 8. All living things, viewed as a group, change over time. • evolution

29. Studying Biology • Different branches: anatomy, botany, microbiology, taxonomy, cytology, etc. • Levels of Organization • Molecular • Cellular • Groups of cells • Organisms • Populations • Communities • Ecosystems • Biosphere

30. 1-4 Tools and Procedures • The Metric System- a common decimal system of units based on multiples of 10 • KHDUDCM: “King Henry Doesn’t Usually Drink Chocolate Milk” • Common Metric Units • Length: meter • Mass: gram • Volume: liter • Temperature: Celcius

31. Analyzing Data • Today, computers do the bulk of biological data analysis • Tables and Graphs

32. Microscopes • Light microscope • Up to 1000x magnification • Compound light microscopes • Two lenses- light passes through an organism • Dyes and stains • Electron microscope • Can view very small organisms • Must be used in a vacuum • TEM (thru) and SEM (over surface)

36. Laboratory Techniques • Cell cultures • Single cell placed in a nutrient dish- grows into a “culture” of cells • Cell fractionation • Separates the different cell parts for individual study • Uses a blender and centrifuge

37. Vocabulary Review • 1. This is the study of the natural world. It can also mean the body of knowledge we’ve built up based on these studies. • A. biology • B. anatomy • C. science • D. observation

38. 2. This occurs when living things come from nonliving things. • A. metabolism • B. homeostasis • C. hypothesis • D. spontaneous generation

39. 3. This is the process of gathering information about events/processes in a careful, orderly way. • A. data • B. inference • C. hypothesis • D. observation

40. 4. This is a logical interpretation based on prior knowledge and experiences. • A. inference • B. hypothesis • C. theory • D. qualitative data

41. 5. This is a well-tested explanation that unifies a broad range of observations. • A. theory • B. hypothesis • C. stimulus • D. inference

42. 6. This is a proposed scientific explanation for a set of observations. • A. inference • B. theory • C. hypothesis • D. a guess

43. 7. This type of reproduction requires only one parent. • A. asexual • B. sexual • C. unisexual • D. mating

44. 8. A collection of living matter enclosed by a barrier that separates it from it’s environment. It is the smallest unit of life. • A. atom • B. cell • C. molecule • D. organism

45. 9. A controlled experiment occurs when you change only this in your set-up. • A. responding variable • B. manipulated variable • C. dependent variable • D. control variable

46. 10. A signal to which an organism responds • A. homeostasis • B. stimulus • C. metabolism • D. trigger

47. 11. This is the branch of science that studies the living world. • A. science • B. anatomy • C. botany • D. biology

48. 12.This process requires an internal feedback mechanism in order to maintain internal balance in an organism. • A. metabolism • B. stimulus • C. homeostasis • D. thermostat

49. 13.This is a lab technique where cells are broken down into their individual parts. • A. cell fractionation • B. cell colonies • C. cell cultures • D. electron microscopy

50. 14. The two types of microscopes are: • A. compound and light • B. light and proton • C. compound and electron • D. light and electron