1. Chapter 1 – The Science of Biology!

2. What words do we associate with science?

3. The goal of science is to investigate and understand the ______________, to explain events, and to use those explanations to make ___________________ To simplify, science is natural world useful predictions an organized way of using evidence to learn about the natural world

4. Science can also just refer to the knowledge scientists have complied Scientific thinking usually starts with ________________ an observation An observation is just gathering info in an orderly way

5. _______= the information gathered through observations There are 2 main types of data: Data qualitative and quantitative

6. Qualitative =____________________—written descriptions of what scientists observe. Quantitative = results from experiments that use __________________________— numerical data  can be used to make graphs, tables, or charts. counts or measurements observational data

7. QualitativeQuantitative

8. ____________ = a logical interpretation based on prior knowledge or experience Inference

9. So we have made our observation, now what? Scientists come up with a ______________ – a proposed explanation for a set of observations Hypothesis’ must be able to be tested – some through ________________________ and some through further collection of data hypothesis controlled experiments

10. new medical treatments, new sources of fuel, different uses for waste Biology can be considered a way of knowing – it is an ongoing process because things continue to change (we don’t leave things alone!!!) Biological research can lead to all sorts of different things;

12. Observations lead to questions – we need a way to test those questions. That’s where an experiment comes in. The basic steps in designing an experiment: 1. Ask the question 5. Draw a conclusion 2. Form a hypothesis from the question 3. Set up a controlled experiment 4. Record and analyze results

13. Aristotle had the idea that living things could come from nonliving things –there were special “vital” forces that brought this about – this became known as To help understand each step, let’s look at some well-known experiments from history This idea persisted for a while – it was only challenged some 400 years ago spontaneous generation

14. These ideas were questioned because of simple observations: maggots on meat, mice on grain, beetles in poo Redi, an Italian physician, came up with a different hypothesis as to why maggots appear on meat __________  they laid eggs (step 1) (step 2)

15. Controlled experiment = an experiment in which only _______________ is changed at a time  all others are kept unchanged Redi came up with a controlled experiment (step 3) one variable (controlled)

16. The independent variable (IV) is what you are changing/controlling/know The dependent variable (DV) is what you are observing/counting/watching What is the IV? What is the DV? What is the IV? What is the DV?

17. We like pictures, but hate numbers, so why do we hate graphs? Its just a picture of our numbers! What is the IV? What is the DV? D ependent R eactive Y -axis M anipulated I ndependent X -axis

18. Line Graph: shows change over time Bar Graph: compares similar but separate categories Circle/pie Graph: part of a whole thing (%) Types of Graphs

19. In Redi’s experiment, he predicted that keeping flies away from meat would prevent maggots, so the variable he changed (IV) was the flies access to the meat

20. Redi thought that if flies couldn't get to the meat there would be no maggots, so he set up meat in 2 sets of jars – most factors were the same: the jar, type of meat, location, temp, time – the only thing that changed was the gauze over the jar

21. Redi recorded his data in notebooks for future generations of scientists Redi’s finding ___________ his hypothesis – if the flies couldn’t get to the meat, there were no maggots (step 4) (step 5) supported

22. Experiments are often repeated to make sure that results are A key assumption in science is that experimental results can be reproduced valid

23. Sometimes it’s not always possible to do an experiment to test a hypothesis _______________ are used as a way to make observations and gather further information to help support a hypothesis Field studies

24. When there is enough evidence from several investigations and a hypothesis is very well supported it is considered Some people might try to criticize something because it is “just a theory”, but in science, a theory is a theory a well tested explanation that unifies a broad range of observations

26. We ask questions all the time; how, what, when, where, why? This is exactly what biologists do – they ask questions about living things Biology is just the study of life Bio = Logy = life the study of

27. So how do we classify living things; what characteristics do they have? All living things (___________) share the following characteristics, they are: organisms

28. _______ = a collection of living matter enclosed by a _____________ that separates the cell from its surroundings 1. Are made up of units called cells Cell barrier

29. _____________________ = cells from 2 parents unite to produce the first cell of the new organism ______________________= the new organism has a single parent  it divides in half to form 2 new organisms 2. Reproduce Sexual reproduction Asexual reproduction

30. Organisms inherit traits from their parents through This code determines the inherited traits of every organism on Earth 3. Based on a universal genetic code DNA – the genetic code

31. For some single-celled organisms, _________ is just an increase in size All of the changes that take place during the life of an organism = 4. Grow and develop growth development

32. Organisms need material and energy just to stay alive! _____________= the combo of chemical reactions through which an organism builds up or breaks down materials during life processes 5. Obtain and use materials and energy Metabolism

33. _________= a signal to which an organism responds Organisms can react to both _____________________ stimuli 6. Respond to their environment Stimulus internal and external

34. _______________ = the process by which organisms keep internal conditions constant for survival Organisms go to great lengths to maintain conditions (temp and water content) 7. Maintain a stable internal environment Homeostasis

35. It can take ________________ of years for these changes to really be apparent Ex. Desert plants have evolved and adapted to living in very hot, dry climates 8. As a group, change over time 100s or 1000s

36. Since there is a very large range of living things, there are many branches of Biology Some of the levels that biology can study are…

38. Scientists use all sorts of tools to help make observations and _____________________ We need a _________________ _________________ so that scientists all over the world can understand it take measurements common system of measurement

39. The ________________ is a decimal system of measurement whose units are scaled on multiples of A revised version of the metric system is the metric system 10 International System of Measurement (SI) Measurement Unit Symbol Lengthmeterm Masskilogramkg Timeseconds TemperatureKelvinK Amount of substance molemol

40. _______________= devices that produce magnified images of structures that are too small to see with the naked eye Microscopes

41. Compound light microscopes use ______ lenses to form an image They can magnify an object by about ____________________ produce an image by focusing visible light rays Light microscopes two 1000 times

42. ______________________ produce an image by focusing beams of electrons Images can get 1000 times more detailed than that of a light microscope There are 2 main types of electron microscopes: Electron microscopes transmission electron (TEM) and scanning electron (SEM)

43. TEMSEM Shines light through thin specimen Specimen is NOT living Used to view details in the specimen Scans surface of specimen Specimen is NOT living Creates a 3D image of the specimen

44. __________ should always be practiced as biologists work with a variety of materials, living and dead P.1066-1076 – reference page for safety procedures P.1068 in book – reference page for safety symbols Lab safety Sharp Object Safety Clothing Protection Safety Eye Safety Chemical Safety