Overview
This lecture introduces the science of biology, explains the scientific method, covers key reasoning types, describes characteristics of life, explores the levels of biological organization, and outlines major sub-disciplines in biology.
The Science of Biology
- Biology is the study of life, ranging from cells to ecosystems.
- Early life consisted of microorganisms; plants and animals appeared later.
- Biology touches daily life through issues like disease outbreaks and environmental challenges.
The Scientific Method
- Science seeks knowledge through observation, experimentation, and the scientific method.
- The scientific method steps: observation, question, hypothesis, prediction, experiment, results, and conclusion.
- A hypothesis must be testable and falsifiable; experiments use variables and controls.
- Scientific reasoning often blends inductive (specific to general) and deductive (general to specific) logic.
- Scientific papers follow a set format: introduction, methods, results, discussion, and conclusion.
- Peer review ensures quality and reproducibility.
Types of Science
- Basic (pure) science expands knowledge without immediate application.
- Applied science uses research to solve real-world problems.
- Both types are important and often interdependent.
Properties of Life
- Living things share characteristics: order, sensitivity/response to environment, reproduction, adaptation, growth and development, regulation, homeostasis, energy processing, and evolution.
- Homeostasis maintains internal conditions within narrow limits.
Levels of Organization
- Biological hierarchy: atom → molecule → organelle → cell → tissue → organ → organ system → organism → population → community → ecosystem → biosphere.
- Cells are the fundamental units of life; organisms can be unicellular or multicellular.
Diversity & Classification of Life
- Evolution drives life's diversity.
- Phylogenetic trees show relationships among species using genetic and physical data.
- Three main domains: Bacteria, Archaea (both prokaryotic), and Eukarya (eukaryotic).
Biological Sub-disciplines
- Branches include molecular biology, microbiology, neurobiology, paleontology, zoology, botany, biotechnology, ecology, and physiology.
- Forensic science uses biology to provide evidence in legal contexts.
Key Terms & Definitions
- Biology — The study of life and living organisms.
- Scientific method — A series of steps for scientific inquiry: observation, hypothesis, experimentation, and conclusion.
- Hypothesis — A testable, falsifiable explanation for an observation.
- Inductive reasoning — Logical thinking that draws generalizations from specific observations.
- Deductive reasoning — Logical thinking that predicts specific outcomes from general principles.
- Homeostasis — Maintenance of stable internal conditions.
- Phylogenetic tree — Diagram showing evolutionary relationships.
- Basic Science — Research for expanding general knowledge.
- Applied Science — Research aimed at solving practical problems.
Action Items / Next Steps
- Review properties of life and levels of biological organization.
- Study examples of inductive vs. deductive reasoning.
- Read about major biological sub-disciplines for further context.