Introduction to Biology

What is Biology? What is scientific inquiry? Describe the steps of scientific inquiry?

Introduction to Biology Biology  The systematic study of life

Introduction to Biology What is Biology?  Anatomy……..gross structure  Physiology………gross function  Histology………tissues  Cell Biology…… cells  Biochemistry…..molecules  Genetics…….inheritance  Zoology……animals  Botany……plants  Microbiology….. microorganisms  Virology…….viruses  Bacteriology……bacteria  Mycology…… fungi

The Nature of Scientific Inquiry Critical thinking  Mental process of judging the quality of information before deciding whether or not to accept it

The Scope and Limits of Science Science is a way of looking at the natural world which helps us to communicate our experiences without bias by focusing only on testable ideas about observable phenomena  Science does not address the supernatural Science  The systemic study of nature

How Science Works Researchers make and test potentially falsifiable predictions about how the natural world works Generally, scientific inquiry involves forming a hypothesis (testable assumption) about an observation then making and testing predictions based on the hypothesis A hypothesis that is not consistent with the results of scientific tests is modified or discarded

Common Research Practices 1. Observe some aspect of nature 2. Frame a question about your observation 3. Propose a hypothesis (a testable explanation of the observation)

Common Research Practices 4. Make a prediction – a statement based on a hypothesis, about some condition that should exist if the hypothesis is not wrong 5. Test the accuracy of the prediction by experiments or gathering information (tests may be performed on a model)

Common Research Practices 6. Assess the results of the tests (data) to see if they support or disprove the hypothesis 7. Conclusions: Report all steps of your work and conclusions to the scientific community

Making Observations: A Field Study

A Scientific Theory Scientific theory  A hypothesis that has not been disproven after many years of rigorous testing  Useful for making predictions about other phenomena

Laws of Nature Law of nature  Generalization that describes a consistent and universal natural phenomenon for which we do not yet have a complete scientific information  Example: gravity

Examples of Scientific Theories

1.7 The Power of Experiments Natural processes are often influenced by many interacting variables Variable  A characteristic or event that differs among individuals

The Power of Experiments Experiments simplify interpretations of complex biological systems by focusing on the effect of one variable at a time Experiment  A test to support or falsify a prediction

Experimental and Control Groups Experimental group  A group of objects or individuals that display or are exposed to a variable under investigation Control group  A group of objects or individuals that is identical to an experimental group except for one variable

Peacock Butterfly Defenses

Example: Butterflies and Birds Question  Why does a peacock butterfly flick its wings? Two hypotheses  Exposing wing spots scares off predators  Wing sounds scare off predators Two predictions  Individuals without spots are eaten more often  Individuals without sounds are eaten more often

Peacock Butterfly Defenses

Experiments and Results Four groups of butterflies were exposed to predators (birds)  Butterflies without spots  Butterflies without sounds  Butterflies without spots or sounds  Control group Test results support both original hypotheses

Results: Peacock Butterfly Experiment

How would you graph this data?