Introduction to General Biology: Foundations, Methods, and Themes

Chapter 1: Introduction to Biology

What is Biology?

Biology is the scientific study of life and living organisms. Understanding biology involves learning the language and concepts that describe the natural world.

• Biology: From the Greek words bios (life) and logos (study).

• Biology covers the structure, function, growth, origin, evolution, and distribution of living organisms.

• Learning biological terminology is essential for mastering the subject.

What is Science?

Science is a systematic approach to understanding the natural and social world through observation and experimentation.

• Science: The pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence.

• Relies on empirical evidence and reproducible results.

The Scientific Method

The scientific method is a logical process used to investigate natural phenomena, develop hypotheses, and test predictions.

1. Observation: Noticing and describing phenomena in a careful, orderly way.

2. Question: Formulating a scientific question based on observations.

3. Hypothesis: Proposing a testable explanation for the observation.

4. Prediction: Making predictions that can be tested by experiments.

5. Experiment: Testing the hypothesis through controlled experiments and data collection.

6. Analysis: Using statistical methods to analyze results.

7. Conclusion: Drawing conclusions that support or refute the hypothesis.

• Hypothesis: A proposed explanation for a natural phenomenon that can be tested and is falsifiable.

• Theory: A broad explanation for a wide range of phenomena, supported by a large body of evidence.

• Scientific Law: A description of an observed phenomenon, not an explanation.

Note: Hypotheses do not become theories, and theories do not become laws. Each serves a distinct role in science.

Variables in Experiments

Experiments involve manipulating and measuring variables to test hypotheses.

• Independent Variable: The variable that is changed or controlled by the scientist.

• Dependent Variable: The variable that is measured or observed in response to changes in the independent variable.

• Controlled (Constant) Variables: All other factors that are kept the same to ensure a fair test.

Scientific Communication and Peer Review

Sharing scientific findings is essential for progress and validation in science.

• Publications: Research is published in scientific journals.

• Seminars, Meetings, Posters: Scientists present and discuss their work with peers.

• Peer Review: Other experts evaluate the quality and validity of research before publication.

Evaluating Scientific Information

Critical thinking is necessary to assess the reliability of scientific information.

• Is the information current?

• Is the source primary and are the authors qualified?

• Are there conflicts of interest?

• Are references provided?

• Is the information peer-reviewed and unbiased?

• Are experiments described in enough detail to be reproduced?

Pseudoscience

Pseudoscience consists of claims or beliefs that are presented as scientific but lack supporting evidence and cannot be reliably tested.

• Tries to appear scientific but does not follow the scientific method.

• Lacks peer review and reproducibility.

Properties of Life

Living organisms share several key characteristics that distinguish them from non-living things.

• Order: Organized structure and complexity.

• Cells: Basic unit of life.

• Growth and Development: Increase in size and change over time.

• Energy Processing: Use of energy to power activities.

• Regulation: Maintaining internal balance (homeostasis).

• Response to Environment: Reacting to stimuli.

• Reproduction: Producing new organisms.

• Evolution: Populations change over generations.

Checkpoint: Consider which properties of life apply to non-living things, such as a car, and which do not.

Major Themes in Biology

Biology is unified by several overarching themes that connect all living things.

• Structure and Function: The way something is structured determines how it functions.

• Information Flow: Genetic information is transmitted and expressed in living organisms.

• Pathways that Transform Energy and Matter: Organisms obtain, use, and transfer energy and matter.

• Interactions within Biological Systems: Organisms interact with each other and their environment.

• Evolution: The process that explains the unity and diversity of life.

Evolution: The Core Theme of Biology

Evolution explains both the similarities and differences among living organisms.

• Life is unified by common cellular processes and the universal chemical structure of DNA.

• Evolution is the process of change that has transformed life on Earth from its earliest forms to the diversity seen today.

• Charles Darwin's "On the Origin of Species" (1859) introduced the concepts of descent with modification and natural selection.

• Natural Selection: The process by which organisms better adapted to their environment tend to survive and produce more offspring.

Classification: The Three Domains of Life

All living organisms are classified into three domains based on cellular and genetic differences.

Domain	Main Characteristics	Examples
Bacteria	Prokaryotic, unicellular, diverse metabolic types	Escherichia coli, Streptococcus
Archaea	Prokaryotic, unicellular, often found in extreme environments	Halophiles, Thermophiles
Eukarya	Eukaryotic, unicellular or multicellular, complex cells with nuclei	Plants, Animals, Fungi, Protists

Additional info:

• Support services such as tutoring and mental health resources are available to students.

• Quizzes will be posted weekly and are open note/book with unlimited attempts.

• Critical thinking and scientific literacy are emphasized throughout the course.