Scientific Inquiry and Experimental Design

Overview of Scientific Inquiry

Scientific inquiry is the systematic process by which scientists investigate natural phenomena, develop explanations, and test hypotheses. It involves observation, experimentation, and communication of results.

• Observation: Using senses to gather information about the natural world.

• Inference: Logical interpretation based on observations.

• Hypothesis: A testable, falsifiable explanation for an observation.

• Prediction: A specific outcome expected if a hypothesis is true.

• Experiment: A procedure to test a hypothesis under controlled conditions.

• Variable: Any factor that can change in an experiment.

Types of Variables

• Independent Variable: The factor changed by the experimenter (manipulated variable).

• Dependent Variable: The factor measured in the experiment (responding variable).

• Controlled Variables (Constants): Factors kept the same in all groups to ensure a fair test.

Experimental Groups

Blind and Double-Blind Experiments

Outcomes of Experiments

• Support the Hypothesis: Data is consistent with the hypothesis (not 'proven').

• Refute the Hypothesis: Data contradicts the hypothesis, leading to revision or new hypotheses.

• Inconclusive: More data or a different design is needed.

Distinguishing Good Science from Pseudoscience

• Good Science: Based on empirical evidence and falsifiable hypotheses.

• Pseudoscience: Lacks empirical support and proper methodology.

Key Scientific Terms

• Theory: A well-supported, broad explanation of natural events (e.g., evolution).

• Law: A statement describing consistent, universal patterns in nature.

• Fact: An observation confirmed repeatedly.

• Bias: Personal preference or opinion that may influence interpretation.

• Qualitative Data: Descriptions (e.g., color, texture).

• Quantitative Data: Numerical measurements.

Properties and Themes of Life

8 Properties of Life

• Order: Organized structure (cells, organs).

• Reproduction: Ability to produce offspring.

• Growth and Development: Change and increase in size over time.

• Energy Processing: Use of energy (e.g., food, photosynthesis).

• Regulation: Maintenance of homeostasis (e.g., body temperature).

• Evolutionary Adaptation: Change over generations.

• Cells: All life is made of one or more cells.

• Response to Environment: Reacting to stimuli.

5 Unifying Themes of Life

• Evolution: Core theme; explains unity and diversity.

• Structure and Function: Form fits function (e.g., wings for flight).

• Information Flow: DNA → RNA → proteins.

• Energy and Matter Pathways: Energy flows, matter cycles (e.g., food webs, water cycles).

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

Levels of Biological Organization

Chapter 2: Chemistry of Life

Basic Chemical Concepts

• Matter: Anything that takes up space and has mass.

• Mass: How much "stuff" is in something.

• Atom: The smallest unit of an element; building block of matter.

• Element: One kind of atom (e.g., oxygen).

• Compound: Two or more elements chemically bonded together.

Elements Essential for Life

• C-H-O-N: Carbon, Hydrogen, Oxygen, Nitrogen – the four elements that make up most living matter.

Comparing Atoms, Elements, Compounds, Matter, and Mass

Subatomic Particles

Atomic Number, Mass Number, and Isotopes

• Atomic Number: Number of protons in an atom (found on the periodic table).

• Mass Number: Number of protons plus neutrons.

• Atomic Mass: Average mass of all isotopes (decimal number on the table).

• Isotopes: Atoms of the same element with different numbers of neutrons (e.g., Carbon-12 vs. Carbon-14).

Chemical Bonds

Properties of Water (Due to Hydrogen Bonds)

• Cohesion: Water sticks to water.

• Adhesion: Water sticks to other substances.

• High Specific Heat: Water resists temperature change.

• Ice Floats: Ice is less dense than liquid water.

Chapter 3: Biological Molecules

Monomers and Polymers

• Monomer: One building block (e.g., glucose).

• Polymer: Many monomers linked together (e.g., starch).

• Dehydration Synthesis: Water is removed to build polymers.

• Hydrolysis: Water is added to break polymers apart.

Organic Compounds and Carbon

• Carbon: Can form 4 covalent bonds, allowing for complex molecules.

• Main atom in living things: Carbon's bonding ability makes it central to life.

Types of Biological Molecules

• Carbohydrates: Sugars and starches; main energy source.

• Lipids: Fats and oils; energy storage and cell membranes.

• Proteins: Made of amino acids; perform most cellular functions.

• Nucleic Acids: DNA and RNA; store genetic information.

Carbohydrates: Monosaccharides, Disaccharides, Polysaccharides

• Monosaccharide: Single sugar molecule (e.g., glucose, fructose, galactose).

• Disaccharide: Two sugars linked (e.g., sucrose = glucose + fructose).

• Polysaccharide: Many sugars linked (e.g., starch, glycogen, cellulose, chitin).

Examples of Carbohydrates

Lipids

• Fats: Made of glycerol and fatty acids; store energy.

• Steroids: Ring-shaped lipids (e.g., cholesterol, hormones).

Proteins

• Made of amino acids: 20 different types.

• Functions: Build body parts, enzymes, hormones, etc.

*Additional info: Some explanations and examples were expanded for clarity and completeness based on standard biology curriculum.*