What is Biology?

The study of life

Biology is Relevant

• Global problems are often Biological ProblemsMedicineBioengineeringEnvironment

Biology can be Controversial

If I choose to limit my family size, what methods of birth control do I use?

Is it right to protect an endangered species at the expense of jobs?

Is it ethical to use fetal tissue in biomedical research?

Are there dangers in cloning humans?Are irradiated foods safe to eat?

What is Life?

Give your own definition

Living Organisms:

• Are highly organized, complex entities• are composed of one or more cells• contain a blueprint of their characteristics• acquire and use energy• carry out and control numerous chemical

reactions• produce offspring similar to themselves• respond to changes in the environment• may evolve into new types of organisms

Inanimate objects may possess some of these characteristics, but not all of them.

Biology is a Branch of Science

• Biology, physics, chemistry, geology, etc. are branches of science

• All branches:– pursuit of information– bodies of knowledge– have unique features/attributes

Study of Life Has Unique Questions

Question #1: “What happens when you push a stationary ball?”

Question #2: “What happens when you push a sleeping dog?”

Physical sciences are deterministic

Action A leads to Response B

Biology is probabilistic

Action A leads to Response B, C, D or E with each having W, X, Y and Z probabilities of occurring

Disciplines of Biology

The disciplines of biology are all interrelated and should not be

viewed as separate, independent entities.

Key Course Concept

The living world is a hierarchy, with

each level of biological structure

building on the level below it.

Hierarchy of Life

Major Theories of Biology

• Evolution by Natural Selection

T. Dobzhansky (geneticist)

“Nothing in biology makes sense

except in the light of evolution”

Major Theories of Biology

• Evolution by Natural Selection• Inheritance

– Gregor Mendel’s experiments leading to the discovery of hereditary “factors” (genes)

Major Theories of Biology

• Evolution by Natural Selection• Inheritance• Cell Theory

Major Theories of Biology

• Evolution by Natural Selection• Inheritance• Cell Theory• Biological Classification

– Carolus Linnaeus’ system of nomenclture– Scientific names unique to a species– Hierarchical system based on relatedness

ItalicizedScientificName

Major Theories of Biology

• Evolution by Natural Selection• Inheritance• Cell Theory• Biological Classification• Bioenergetics

– energy that powers life– operates under same rules that govern energy in

the inanimate universe

Major Theories of Biology

• Evolution by Natural Selection• Inheritance• Cell Theory• Biological Classification• Bioenergetics• Homeostasis

– organisms function best under narrow range of conditions– maintain stable internal conditions– allows organism to live in a wider range of conditions

Major Theories of Biology

• Evolution by Natural Selection• Inheritance• Biological Classification• Bioenergetics• Homeostasis• Ecosystem

– organisms interact with each other and their environment

– “Entangled Bank”

How is Biology/Science Studied?

• Observation• Questioning• Hypothesis• Testing• Explanation• These topics comprise the Scientific

Method

Observation

“Seeing” and recognizing something that is of interest,

concern, or a curiosity

Questioning

• Asking “why does this happen”, “how does this work”, etc.

• Is it a testable question?– If yes, then it is a question that fits the

scientific method

Testing

• Develop a study or experiment that will test the hypothesis

• Should have sound experimental design• Should be repeatable

Explanation

• Interpretation of findings• Was the hypothesis rejected?• How do findings relate to those of others?• What is the significance of the findings?

Hypothesis

• A preliminary answer– previous experience– published information– best guess

• A hypothesis does not have to be correct• Scientific investigation attempts to falsify

a hypothesis

Report Your Findings!!!!

• Graphically• Numerically• Written• Orally