Foundations of General Biology: Scientific Method, Evolution, and Biological Organization

Biology and Science

Definitions and Scope

Biology is the scientific study of life, encompassing the structure, function, growth, origin, evolution, and distribution of living organisms. Science is a systematic approach to understanding the natural explanations to specific questions, relying on observation, experimentation, and evidence-based reasoning.

• Biology: Focuses on living organisms and their interactions.

• Science: Uses systematic inquiry to answer questions about the natural world.

Scientific Method

Steps and Features

The scientific method is a structured process used to investigate phenomena, acquire new knowledge, or correct and integrate previous knowledge. It is fundamental to all scientific disciplines, including biology.

1. Start with observation: Record information about a phenomenon.

2. Ask questions: Scientific inquiry designed to address a gap in knowledge.

3. Hypothesis: Testable explanation for a set of observations based on available data.

4. Prediction: Forecast that follows logically from a hypothesis.

5. Scientific Test: A procedure carried out to support or reject a hypothesis (includes control group and experimental group).

6. Results: The outcome of the experiment.

7. Determination: Whether the hypothesis should be supported or rejected.

• Theory: An explanation broader in scope than a hypothesis, supported by a large body of evidence.

• Fact: A piece of information correct based on all current info; not subject to opinion and can be independently verified.

Features of Science

• Falsible

• Testable

• Logical

• Objective

• Systematic

• Repeatable

• Inquiry-based

• Observable

Key Features of Life

Characteristics and Requirements

Living organisms share several key features that distinguish them from non-living matter.

• Genetic information: Mutations can occur, leading to variation.

• Energy: Organisms require energy for survival and growth.

• Reproduction: Ability to produce offspring.

• Cells: Basic unit of life.

• Capacity to evolve: Populations change over time.

• Homeostasis: Maintenance of stable internal conditions.

• Growth and development: Organisms increase in size and complexity.

• Response to environment: Ability to react to stimuli.

Population

A population consists of all individuals living in a specific area.

Biological Diversity

• Organisms have different structures and functions.

• Interactions occur within species and between different species.

Evolution

Definition and Mechanisms

Evolution is the change in the heritable characteristics of biological populations over successive generations. It is the central unifying concept in biology.

• Biological Evolution: Change in allele frequencies over generations.

• Unit of Evolution: The generation is the basic unit for evolutionary change.

• Diploid: Organisms with two sets of chromosomes (one from each parent).

Tissues, Cells, Organelles, Molecules

Organization and Chemical Basis of Life

Living organisms are organized into hierarchical levels, from molecules to cells, tissues, organs, and organ systems. The chemical basis of life is essential for understanding biological structure and function.

• All living organisms can be broken down small enough to chemical elements.

• Matter: Anything that has mass. Light is an example of something that does not matter; it is a wave of energy. Sound and heat are also forms of energy, not matter.

• All molecules have compounds, but not all compounds are molecules; molecules can stand alone.

• Element: A substance that cannot be broken down into other substances.

• Properties of a compound are not the exact combinations of elements to make up the compound.

Additional info:

• Compound: A substance formed when two or more elements are chemically bonded together.

• Example: Water (H2O) is a compound made from hydrogen and oxygen elements, but its properties are different from those of its constituent elements.