Introduction to Biology and Scientific Inquiry

Biology is the study of life across scales ranging from microscopic to global.
Science is an approach to studying and understanding the natural world through inquiry.

Inductive Reasoning: Discovery-based logic moving from specific observations to general conclusions.
Deductive Reasoning: Hypothesis-based logic moving from general premises to specific results.
Scientific Method Process: Involves sequential steps of Observations, Questions, Hypothesis, Predictions, Experimentation, and Conclusions.
Types of Data:
- Qualitative Data: Descriptive, non-numerical observations.
- Quantitative Data: Numerical measurements analyzed using statistics to test significance.
Hypotheses: Tentative, testable, and falsifiable answers to specific questions.

Variables in Experimentation:
- Independent Variable: The factor manipulated or changed.
- Dependent Variable: The observed outcome resulting from the manipulation.
Experimental Setup: Utilizes control groups and experimental groups.
Model Systems: Organisms used to test hypotheses when human testing poses ethical or practical issues.
- C. Elegans: Used for studying animal development and genetics.
- Lab rat: Used for testing drugs and treatments designed for humans.
- HeLa cells: Used for research on HIV, human growth hormone, and other fields.
- Zebrafish (Danio rerio): Used in developmental biology, cancer, toxicology, and drug discovery.
Scientific Theories: Broad explanations supported by extensive evidence, such as evolution by natural selection or coat coloration adaptation in mice like Peromyscus polionotus.

Biological Hierarchy: Atoms, Molecules, Organelles, Cells, Tissues, Organs and Organ Systems.
Cell Unit: The cell is the basic structural and functional unit of life.
- Cell Types: Prokaryotic and Eukaryotic.
Key Organizational Approaches:
- Reductionism: Reducing complex systems to simpler, manageable components.
- Emergent Properties: New properties arising at higher hierarchy levels due to component interactions.
- Systems Biology: Analyzing interactions across an entire biological system.
Structure and Function: A direct correlation exists between structure and function at every biological level.

DNA and Genes: DNA contains genetic code, with genes serving as discrete hereditary units.
Central Dogma and Gene Expression: Process of transferring genetic information from DNA to RNA to Protein.
Analytical Fields:
- Genomics: Study of whole sets of genes and species genome comparisons.
- Proteomics: Study of sets of proteins (proteomes) and their properties.
- Bioinformatics: Use of computing tools, software, and mathematical models to analyze large biological data sets.

Biological Work: Moving, growing, reproducing, and cellular activities require energy.

Symbiotic Relationships: Close, prolonged associations between different biological species, including Mutualism, Commensalism, and Parasitism.
Environmental Interactions: Organisms interact with environments; human-driven climate change impacts species behavior, such as Sceloporus lizards spending more time in heat refuges and less time foraging.

Definition: Genetic change in a population over time.
Core Importance: Highlighted by Theodosius Dobzhansky: "Nothing in Biology makes sense except in the light of Evolution."
Three Domains of Life:
- Bacteria: Widespread prokaryotes.
- Archaea: Diverse prokaryotes.
- Eukarya: Eukaryotic organisms divided into Kingdom Plantae, Kingdom Fungi, Kingdom Animalia, and Protists.
Charles Darwin and The Origin of Species:
- Concept 1: Descent with modification (unity and kinship from common ancestors).
- Concept 2: Natural selection (driven by Competition, Variation, Heritability, and Differential Reproduction).