Scientific Method Overview

Scientific Method

• A systematic approach to investigating phenomena and acquiring knowledge.

Key Concepts in the Scientific Method

• Hypothesis: A proposed explanation for a phenomenon, testable through experiments.
• Theory: A well-supported explanation of natural phenomena, based on evidence.
• Controlled Experiment: An experiment where all variables are controlled except for the one being tested.
• Independent Variable: The variable deliberately changed in the experiment.
• Dependent Variable: The variable measured as a result of the independent variable.
• Control Group: A group not exposed to the treatment, used as a comparison.
• Experimental Group: A group exposed to the treatment being tested.
• Constants: Factors that remain the same throughout the experiment.
• Replicates: Repeating the experiment to ensure reliability.
• Quantitative Data: Numerical data collected during experiments.
• Qualitative Data: Descriptive data collected, often non-numerical.

Biology Fundamentals

• Cells: The basic units of life, found in all living organisms.
• Asexual Reproduction: Reproduction without fusion of gametes.
• Sexual Reproduction: Reproduction involving the fusion of male and female gametes.
• DNA: Deoxyribonucleic acid, carrying genetic information.
• Development: The growth and differentiation of an organism.
• Metabolism: The chemical reactions supporting life.
• Autotroph: An organism that produces its own food (e.g., through photosynthesis).
• Heterotroph: An organism that consumes other organisms for food.
• Stimulus: A detectable change in the environment causing a response.
• Homeostasis: Maintaining stable internal conditions.
• Evolution: The change in heritable characteristics of biological populations over generations.

Chemistry Fundamentals

• Atom: The basic building block of matter.
• Proton: Positively charged subatomic particle in the nucleus.
• Neutron: Neutral subatomic particle in the nucleus.
• Electron: Negatively charged subatomic particle orbiting the nucleus.
• Valence Electrons: Electrons in the outermost shell, involved in bonding.
• Covalent Bond: Atoms share electron pairs.
• Molecule: Multiple atoms bonded together.
• Ionic Bond: Transfer of electrons between atoms.
• Hydrogen Bonds: Weak attractions between hydrogen and electronegative atoms.
• Polar Molecules: Unequal charge distribution within a molecule.
• Hydrophobic: Substances repelling water.
• Hydrophilic: Substances attracted to water.
• Cohesion: Attraction between like molecules.
• Surface Tension: The resistance of a liquid's surface to external force.
• Adhesion: Attraction between unlike molecules.
• Heat Capacity: The amount of heat required to change temperature.
• Solution: Homogenous mixture of two or more substances.
• Solute: The substance dissolved in a solution.
• Solvent: The substance that dissolves the solute.
• pH: Measure of acidity or basicity of a solution.
• Acid: Substance releasing protons (H+).
• Base: Substance accepting protons (H+).

Biological Molecules

• Macromolecule: Large complex molecule, often assembled from smaller subunits.
• Carbohydrate: Organic compound with carbon, hydrogen, and oxygen (1:2:1 ratio).
• Lipid: Hydrophobic molecule (e.g., fats, oils).
• Protein: Large biomolecule made of amino acid chains.
• Nucleic Acid: Biomolecule essential for life (e.g., DNA, RNA).

Chemical Reactions

• Chemical Reaction: Transformation of one substance to another.
• Conservation of Matter: Matter isn't created or destroyed in a closed system.
• Reactants: Substances undergoing change in a reaction.
• Products: Substances formed from the reaction.
• Enzyme: Protein catalyst for chemical reactions.
• Anabolic: Building complex molecules.
• Catabolic: Breaking down complex molecules.
• Endothermic: Reaction absorbing energy.
• Exothermic: Reaction releasing energy.

Ecology

• Ecosystem: Interacting organisms and their physical environment.
• Biotic: Living components of an ecosystem.
• Abiotic: Non-living components of an ecosystem.
• Producer: Organism creating its own food.
• Consumer: Organism consuming other organisms.
• Carnivore: Meat-eating organism.
• Herbivore: Plant-eating organism.
• Omnivore: Eating both plants and animals.
• Detritivore: Consuming dead organic material.
• Decomposer: Breaking down dead organisms.
• Scavenger: Consuming dead organisms not killed by them.
• Food Chain: Linear feeding sequence through an ecosystem.
• Food Web: Complex network of interconnected food chains.
• Trophic Level: Organism's position in a food chain.
• 10% Rule: Only about 10% energy transfers between trophic levels.
• Trophic Cascade: Impact of top predators on other species.
• Water Cycle: Continuous movement of water.

Cell Structure and Function

• Cell Theory: All living organisms are composed of cells.
• Prokaryotic Cell: Lacks a nucleus and membrane-bound organelles.
• Eukaryotic Cell: Has a nucleus and membrane-bound organelles.
• Cytoplasm: Substance inside the cell, excluding the nucleus.
• Nucleus: Organelle containing cell's genetic material.
• Vesicle: Small membrane-bound sacs for transport within the cell.
• Ribosomes: Synthesize proteins.
• Endoplasmic Reticulum: Synthesizes proteins and lipids.
• Membrane Proteins: Proteins associated with biological membranes.
• Phospholipid: A major component of cell membranes.
• Semipermeable Membrane: Allows selective passage of molecules.
• Active Transport: Movement of molecules across membranes using energy.
• Osmosis: Diffusion of water across a semipermeable membrane.
• Tonicity: The ability of a solution to cause a cell to gain or lose water.
• Dilute: Low solute concentration.
• Concentrated: High solute concentration.
• Isotonic: Equal solute concentration.
• Hypertonic: Higher solute concentration outside the cell.
• Hypotonic: Lower solute concentration outside the cell.
• Lysis: Cell bursting.
• Crenation: Cell shrinking.
• ATP/ADP: Energy currency of cells (ATP) and product of its use (ADP).