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Chapter 1: The Science of Biology. 1-1 What is Science?. Key Concepts. Explain what the goal of science is. Explain what hypothesis is. What Science Is and Is Not. Deals with the natural world Organization looking for patterns and similarities Test evidence to explain an event.
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Key Concepts • Explain what the goal of science is. • Explain what hypothesis is.
What Science Is and Is Not • Deals with the natural world • Organization looking for patterns and similarities • Test evidence to explain an event
Thinking Like a Scientist • The Scientific Method • Observe • Collect data • Make an inference • Form a hypothesis • Design an experiment • Draw a conclusion • Report findings
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)
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
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
Science and Human Values • Requires scientists to consider laws and moral principals
Key Concepts • Describe how scientists test hypotheses. • Explain how a scientific theory develops.
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)
Designing an Experiment • Recording and analyzing results • Drawing a conclusion • Assume patterns in nature are consistent
Publishing and Repeating Investigations • If the variable is consistent, the results should always be the same
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
When Experiments Are Not Possible • Ethical considerations must be taken into account
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
Key Concepts • Describe some characteristics of living things. • Explain how life can be studied at different levels.
Biology • Biology means the “study of life” • It is the science that seeks to understand the living world
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
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
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
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
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.
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
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
Lab Techniques • Cell Cultures • Reproduce cells to examine • Cell fractionation • Separate the cell into different parts
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