Chapter 1 The Science of Biology

1. Chapter 1The Science of Biology CP Biology

2. Chapter 1:The Science of Biology • 1.1: What is Science? • 1.2: Science in Context • 1.3: Studying Life • Measurement • Safety

3. 1.1The Science of Biology

4. An organized way of studying things and finding answers What is Science?

5. The Scientific Method • 1.) State the Problem • 2.) Gather Data • 3.) Form a Hypothesis • Hypothesis: Educated Guess • 4.) Perform an Experiment • Control • Variable • 5.) Analyze the Data • Sources of error • 6.) Draw Conclusions

6. The Scientific Method

7. Parts of an Experiment • Control: the standard to which the outcome of a test is compared • Variable: something in the experiment that you are testing that can change • Independent variable: (manipulated) deliberately changed • Dependent variable: (responding variable) changes in response to the independent variable

8. 1.2:Science in Context

9. What scientific attitudes help generate new ideas? • Curiosity • Skepticism • Open-mindedness • Creativity • Arise from practical problems • Technology – discovery in one field of science may lead to new technologies • Peer review –sharing knowledge and ideas

10. An explanation of things or events based on scientific knowledge that is a result of many observations and experiments Well tested explanation DOES NOT change unless new evidence becomes available Scientific Theory

11. A statement about how things work in nature that seems to be true all the time Less likely to change than scientific theories Scientific Law

12. Science and Society • Science, ethics, and morality • Pure science does NOT include ethical or moral viewpoints • Avoiding Bias • Bias: a particular preference or point of view that is personal rather than scientific

13. 1.3Studying Life

14. Characteristics of Living Things • 1.) are made up of cells • 2.) based on the universal genetic code (DNA) • 3.) maintain a stable environment (homeostasis) • 4.) Respond to their environment • 5.) Use energy (metabolism) • 6.) Grow and develop • 7.) Reproduce • 8.) Evolve

15. Any living thing is called an Organism. Cells are the smallest unit of an organism that carries on the functions of life. 2 Types of Organisms Single cell: made of just one Multicellular: made of many 1.) Living things are made up of cells

16. 2.) Living things are based on the universal genetic code (DNA) • DNA: deoxyribonucleic acid • Located in the nucleus of cells • Contains genetic information • Passed on to offspring

17. 3.) Living things maintain a stable environment • All organisms need to keep their internal environment relatively stable, even when external conditions change • homeostasis

18. 4.)Living things respond to their environment • Stimulus: • Anything that causes a change in an organism • Examples: • Light • Temperature • Sounds • Response: • A reaction to a stimulus

19. Example of Stimulus/Response A cat hears a can of food being opened (assumes it’s for him) and usually runs to the kitchen

20. 5.) Living things use energy

21. 6.) Living things grow and develop

22. 7.) Living things reproduce • Sexual Reproduction: • Cells from 2 parents unite to form the first cell of a new organism • The offspring is genetically DIFFERENT • Asexual Reproduction: • A single organism produces offspring identical to itself • Example: bacteria

23. Sexual vs. Asexual Reproduction Paramecium dividing (Asexual Reproduction)

24. 8.) Living things evolve • Over generations, groups of organisms evolve, or change over time. • Evolutionary change links all forms of life to a common origin more than 3.5 billion years ago. • Evidence is found in all aspects of living things, fossil organisms, physical freatures to DNA.

25. What do living things need? • A place to live • Raw materials • Examples: • Water • Food

26. Central Themes of Biology • Cellular basis of life • Information and heredity • Matter and energy • Growth, development, and reproduction • Homeostasis • Evolution • Structure and function • Unity and diversity • Interdependence in nature • Science as a way of knowing

27. Field of Biology • Global ecology • An ecologist studies the environment • Biotechnology • Ex: plant biologist analyzes genetically modified rice plants • Building tree of life • Ex: a paleontologist studies signs of ancient life • Ecology & evolution of infectious diseases • Ex:a wildlife biologist studies a group of wild gelada baboons • Genomics and molecular biology • a molecular biologist analyzes a DNA sequence

28. Scientific Measurements

29. SI Units of Measurement • Length – meter ruler (m) • Mass – scale (g) • Volume • solids: • regular shaped objects • length x width x height (cm3) • irregular shaped objects • water displacement • liquids – graduated cylinder (mL)

30. Metric PrefixesKing Henry Died Drinking ChocolateMilk

31. Practice ProblemsPrefix Conversions • 45.3g = 45300mg • 0.345 mL = 0.00000345hL • 89m = 89000mm • 45000dl = 4.5kl • 2.5kg = 250000cg • 7dkm = 700dm

32. Density • Formula: D = m v • Units: • solids: g/cm3 • liquids: g/mL • Density of water: 1 g/mL • if an object/liquid has a density less than that of water, it will float; • if it has a density greater than that of water, it will sink • 1 mL = 1 cm3

33. Practice ProblemsDensity • Example 1: A solution has a mass of 2.5g and a volume of 37mL. What is the density? m = 2.5g v = 37 ml D = x D = m/v D = 2.5 37 = 0.068 g/mL • Example 2: A solid object has a mass of 79.35g and a volume of 12.4mL. What is the density of the object? m = 79.35 v = 12.4mL D = x D = m/v x = 79.35 12.4 = 6.4 g/cm3

34. Lab Safety

35. Lab Safety RULES • DO NOT joke around while doing labs. • Stay at your lab table during the entire lab. • Follow all directions and precautions CAREFULLY!!! • Tie long hair back. • Roll up loose or hanging sleeves. • Wear gloves (when applicable). • Wear goggles (when applicable). • Clean up your table and all materials. • Wash your hands before leaving the lab.

36. Lab Safety Symbols