The Science of Biology

1. The Science of Biology Chapter 1

2. What are some questions a biologist might ask about the following pictures?

6. To investigate and understand the natural world (Why things happen) To explain events in the natural world (How things happen) To use those explanations to make useful predictions. (What next?) Science is an organized way of using evidence to learn about the natural world. It also refers to the body of knowledge that scientists have built up. What do you think are the goals of science?

7. More info on the scientific method

8. When do you use the scientific method? Creative problem solving…….

10. Observation is the process of gathering information about events or processes in a careful, orderly way. Uses the senses, particularly sight and hearing. What are some examples? Inference is a logical interpretation based on prior knowledge or experience. Scientists use data to make inferences. Observation vs. Inference

12. Design and Conduct the Experiment: testing your hypothesis • In a controlled experiment, whenever possible, a hypothesis should be tested by an experiment in which only ONE variable is changed at a time. All other variables should be kept unchanged or controlled. • There are two variables: manipulated and responding.

15. Quantitative (expressed in numbers, obtained by counting or measuring.) Quantity The plant has 4 buds. Qualitative (descriptive and involve characteristics that usually can’t be counted.) Quality The leaves of the plant are very green. 2 Kinds of Data

16. What kind of graph is this?          1. What was the minimum wage in January, 1978? 2. When did the minimum wage reach $3.35? 3. Between what time periods was the largest increase in minimum wage? 4. Based on your observations of the graph, make a prediction about what the wage might be in the year 2000.

18. Science experiments use… Independent variables – the onefactor changed by the person doing the experiment. Dependent variables– the factor being measured in an experiment. Constants– all the factors that stay the same in an experiment.

19. The manipulated variable (independent variable) is condition that is changed. (Time, or actual part of testing.) The responding variable (dependent variable) changes in response to the manipulated variable. (Growth, amounts, etc.) Variables Growth (meters) Time (years)

20. How is this graph different? Do they have the same information? • What is the manipulated variable? • Minimum wage is dependent on (or responds to) the year. • What is the responding variable?

21. In the early 1600’s scientists believed that life came from non-living things and ethers (special forces). In the late 1800’s the theory of biogenesis replaced spontaneous generation. Francesco Redi did an experiment with maggots and from where they come. Biogenesis means that life comes only from other life. Bio-life Genesis- beginning Spontaneous Generation or Biogenesis?

22. What were Redi’s observations? What was his hypothesis? What was his experiment? Manipulated Variable? Responding Variable? What data did he collect? What was his conclusion? Applying scientific method

23. John Needham wanted to prove that spontaneous generation could occur. Boiled gravy. Sealed it.. Flask had microorganisms. He concluded they came from the gravy (non-living) because he boiled and killed them all. Lazzaro Spallanzani retested Needhams work, thinking Needham did not boil the gravy enough. Boiled gravy. Flask open, flask sealed. Open flask had microorganisms, sealed did not. Testing Redi What did Needham conclude? Spallanzani? What were controlled variables? Manipulated?

24. Wanted to settle argument that Spallanzani’s experiment was or wasn’t a fair test because air had been excluded from sealed jar. Boiled broth Broth free of microorganisms for a year. Curved neck removed. Broth had microorganisms. What was Pasteur’s conclusion? Pasteur

25. Saved French wine industry, unexplained souring of wine. Saved silk industry, endangered by silkworm disease. Uncovered nature of infectious diseases showing they were result of microorganisms entering body. Anthrax vaccine. So, what is pasteurization? Redi and Pasteur’s experiment: Active Art Impacts of Pasteur

26. A scientific theory applies to a well-tested explanation that unifies a broad range of observations. Theories may sometimes be modified as new evidence is found. Atom theory Evolutionary theory Theories in science are not like everyday theories. Ie. I have a theory the IU football team will win today. That statement is not back by any evidence. It is just a belief. Scientific Theories

27. Life and How It Came to Be • We live in the biosphere. • What is the biosphere? • All living things are called organisms. • Bio-life • -Sphere, circle

28. 1. Living things are highly organized. CellTissueOrganOrgan System Cell- basic unit of organization. Some cells are made up on one cell –unicellular. Ie. Protists and Bacteria Others are multicellular. Plants and animals The Properties of Life

29. 2. All organisms are able to take in energy from the environment and use it for their life processes. (metabolism) 3.They grow and develop. 4. They reproduce (sexually or asexually). 5. They respond to environmental stimuli and adapt to the environment. Other characteristics of living things…

30. 6. Maintain a stable internal environment- homeostasis. 7. Are based on a universal genetic code. 8. Taken as a group, change over time (evolution). Living characteristics cont.

31. The ability to respond and adapt to changes in the environment is one of the most important characteristics of living things. Why? Who is Charles Darwin? Darwin explained how only those organisms that can successfully compete for Earth’s resources can survive and reproduce. The traits that allow the organisms to survive are passed onto offspring. What is this called? Adaptation to the Environment

32. Metabolism is the combination of all the chemical changes that take place in an organism. Do you have a high or low metabolism? Organisms use compounds that contain energy in chemical bonds as a source of energy. Where do you get you energy from and what is it used for? Energy in Life’s Processes

33. Homeostasis is the tendency of an organism to maintain stable internal conditions. “Internal balance System” Can you give any examples of homeostasis? Homeostasis and Control

34. Using the characteristics of living things, tell whether each thing is living or non-living. Horse Flower Lichen Cloud Bacteria Fire Snowflake Living or Non-Living

35. Cells are the fundamental units that exhibit all of the characteristics of living things. What is someone called who studies cells? Atoms are the smallest units of organization. They form molecules. The Organization of Life

36. Tissues are made up of cells working together to perform a specific function. Muscle tissue Organs are made up of several types of tissues that function together for a specific purpose. Heart is made up of muscle tissue. What’s Next?

37. Organ Systems are made up of several organs working together for a function. Individuals are made up by the organ systems. Populations are a group of individuals that live in one area. The different populations make up a community. Communities and their non-living surroundings make up ecosystems. and The part of the earth that contatins all ecosystems is the biosphere. Keep Going..

38. Scientists use the metric system when collecting data and performing experiments. It is a decimal system of measurements whose units are based on certain physical standards and are scaled on multiples of 10. (SI) The Metric System

39. Length Volume Mass Time Temperature Meter Liter Gram Second Celsius What is each measured in?

40. Ones place 5 Tenth place .5 Hundredth place .05 Thousandth place .005 Depending on what you are measuring and how precise you want to be you will need to be consistent in the number of decimal places you round to. You should not round the ones place numbers up or down. Measuring

41. Conversions • Kilo King • Hecta Herrold’s • Deca Dad • Unit Underestimated • Deci Demetri’s • Centi Cute • Milli Muscles

42. 2.54 cm.=1 inch. 1 kg =1000 grams 10 mm= 1 cm. 1 m = 100 cm. Practice these conversions. How many cm are there in 5 inches? How many mm are there in 3 cm.? How many feet in a mile? Some things you should know..

43. Light Microscopes Compound- two or more lenses, light passes through specimen. The first microscopes were a single lens, like a magnifying glass. Electron Microscopes use electrons to create an image of the specimen. A monitor needed. Only dead material and has to be used in a vacuum. The Development of the Microscope

44. Scanning Electron Microscope (SEM)- Bounces e- off specimen Creates 3-D image Magnifies up to 60,000x Transmission Electron Microscope (TEM) E- pass through Specimens must be very thin Magnifies up to 2,000,000x Types of Electron Microscopes

45. Scanning Interferometric Apertureless microscope (SIAM) 500x better resolution than light microscopes. Can image single atoms. Can be used for DNA sequencing. A New Microscope

46. Cell cultures are groups of cells made from one cell dividing. They are grown in a petri dish on a nutrient solution. They can be used to test cell responses under controlled conditions to study interactions between cells and to select specific cells for further study. Cell fractionation is used to separate the different cell parts. Cells are broken into pieces using a special blender. Broken cells are added to liquid and placed in tube. Centrifuge spins tube. Most dense parts go to bottom and least dense to the top. Lab Techniques

47. Biotechnology is the use of organisms to produce things that people need. Food Medicine Clothing- silk, wool, leather Additional Resources such as wood and coal. Biotechnology

48. Lab Safety! • Wear goggles. • Tie hair back. • No loose clothes. • Don’t smell, eat, drink anything. • If you break something, don’t try to pick it up. • Don’t use anything not labeled. • Wash hands. • Ask teacher for any help. • No horseplay!

49. Ch. 1 Review • Go to the following link click on your text book. Check out the SciLinks and take the Self-Test for Ch. 1 • Ch. 1 Review