Chapter 1: The Science of Biology

1. Chapter 1: The Science of Biology

2. 1-1 What is Science?

3. Key Concepts • Explain what the goal of science is. • Explain what hypothesis is.

4. What Science Is and Is Not • Deals with the natural world • Organization looking for patterns and similarities • Test evidence to explain an event

5. Thinking Like a Scientist • The Scientific Method • Observe • Collect data • Make an inference • Form a hypothesis • Design an experiment • Draw a conclusion • Report findings

6. Thinking Like a Scientist • Observation(gathering information about events or processes carefully) uses the senses • 2 types of data • Quantitative- involves numbers • Qualitative- involves observations • Make an inference(a logical interpretation based on prior knowledge)

7. Explaining and Interpreting the Evidence • Explain events logically and analytically • Form a hypothesis (scientific explanation for a set of observations) • Use prior knowledge, logical inferencing, & informed, creative imagination • To make a valid conclusion, it must be based on reliable data

8. Science as a Way of Knowing • It is an ongoing process • It is always changing • Must be skeptical and open-minded • Involves the whole physical universe as a system • Biologists focus on living systems

9. Science and Human Values • Requires scientists to consider laws and moral principals

10. 1-2 How Scientists Work

11. Key Concepts • Describe how scientists test hypotheses. • Explain how a scientific theory develops.

12. Designing an Experiment • Ask a question • Form a hypothesis • Many scientists believed in spontaneous generation(life came about from nonliving matter) • Set up a controlled experiment • The factors that change are variables • Controlled experiment(only one variable is changed) • Manipulated variable(the variable that is changes)

13. Designing an Experiment • Recording and analyzing results • Drawing a conclusion • Assume patterns in nature are consistent

14. Publishing and Repeating Investigations • If the variable is consistent, the results should always be the same

15. Scientists and Their Findings • 1668 Redi notice maggots on meat • At the same time Leeuwenhoek was creating lenses • Mid-1700’s Needham spontaneous generation occurs using gravy • Spallanzani repeated the experiment but sealed one flask • 1800’s Pasteur used a flask with a curved neck to prove microorganisms do not form from nonliving things • Pasteur made many discoveries involving microorganisms

16. When Experiments Are Not Possible • Ethical considerations must be taken into account

17. How a Theory Develops • No theory(after repeated investigations, a hypothesis is supported) is considered absolute truth • Theories allow scientists to make predictions about new situations

18. 1-3 Studying Life

19. Key Concepts • Describe some characteristics of living things. • Explain how life can be studied at different levels.

20. Biology • Biology means the “study of life” • It is the science that seeks to understand the living world

21. Characteristics of Living Things • Living things: • Are made up of units called cells • Reproduce • Are based on a universal genetic code • Grow and develop • Obtain and use materials and energy • Respond to their environment • Maintain a stable internal environment • As a group, change over time

22. Characteristics of Living Things • Made Up of Cells • There are unicellular (single celled organisms) and multicellular • Reproduction • 2 kinds: • Sexual(2 cells from different parents unite to form the first cell of a new organism) • Asexual (the organism has a single parent) • Based on Genetic Code • Information about genetic code is carried on DNA

23. Characteristics of Living Things • Growth and Development • Multicellular organisms go through a development process • Need for Materials and Energy • Metabolism(building up and breaking down of materials to produce energy to carry out life’s processes) • In plants it’s called photosynthesis • Responds to the Environment • Detect stimuli in the environment

24. Characteristics of Living Things • Maintaining Internal Balance • Homeostasis(keeping internal conditions constant which allows for survival) • Temperature • Water content • Evolution • Any given organism can evolve or change over time

25. 1-4 Tools and Procedures

26. Key Concepts • Describe the measurement system most scientists use. • Explain how light microscopes and electron microscopes are similar and different. • Describe 2 common laboratory techniques. • Explain why it is important to work safely in biology.

27. Common Measurement System K H D m l g D C M • A revised metric system called the Internationals System of Units (SI) • Based on units of 10

28. Microscopes • Two problems with microscopes: • How big can you make the object? • How sharp is the image? • Light Microscopes • Allow light to pass through the object • Can view while still alive • Electron microscopes • Use beams of electrons • Requires a vacuum to operate • Specimen cannot be alive

29. Lab Techniques • Cell Cultures • Reproduce cells to examine • Cell fractionation • Separate the cell into different parts

30. Working Safely in Biology • Before you start, make sure you read all of the instructions!!! • Prepare properly, gathering safety material and equipment • Ask a teacher if you have any questions