Scientific Method - Ch 1

Scientific Method - Ch 1

• Accuracy measures how close experimental results are to the true value. Correct thermometer calibration is essential for accurate temperature readings.
• Reliability ensures consistent results when repeating an experiment. Similar results upon repetition indicate reliability.
• Validity confirms an experiment measures what it's intended to. Controlling extraneous variables ensures results reflect the independent variable's impact.
• Example: To test temperature's effect on plant growth, maintain constant light and water levels to isolate temperature's influence.
• Hypothesis: A testable prediction of experimental outcomes. Often uses the "if... then..." format.
  • Example: "If temperature increases, then the rate of photosynthesis in plants increases."
• Independent Variable: The variable changed or manipulated in an experiment.
  • Example: Temperature in a plant growth experiment.
• Dependent Variable: The variable measured in response to changes in the independent variable.
  • Example: Photosynthesis rate in a plant growth experiment.
• Controlled Variables: Variables kept constant to confirm changes in the dependent variable result from the independent variable alone.
  • Example: Light levels, plant type, soil quality.

Biodiversity and Classification - Ch 2

• Genetic Diversity: Variation in genes within a species or population.
• Species Diversity: The variety of species within a specific region or habitat.
• Ecosystem Diversity: The variety of ecosystems within a geographical area.
  • Example: Forests, wetlands, deserts, and coral reefs in Australia represent different ecosystems.
• Taxonomic Levels:
  • Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species
  • Example: The scientific name for humans is Homo sapiens, where Homo is the genus and sapiens is the species.
• Binomial Nomenclature: The system of naming organisms using two parts: genus and species. (Genus species)
  • Example: Homo sapiens for humans; Panthera leo for lions.
• Phylogenetic Trees/Cladograms: Diagrams illustrating evolutionary relationships between species.
  • Show evolutionary pathways from common ancestors.
  • Example: A cladogram may illustrate the shared ancestry of humans, apes, and monkeys.

Chapter 3: Ecosystems and Interactions

• Ecosystem: A community of living organisms (biotic factors) and their physical environment (abiotic factors) interacting within a specific area.
  • Examples: Rainforests, coral reefs, deserts, grasslands.
• Biotic Factors: The living components of an ecosystem (e.g., plants, animals, bacteria).
• Abiotic Factors: The non-living components of an ecosystem (e.g., water, sunlight, temperature, soil).
• Ecological Niche: The role and position a species plays in its environment, including its interactions with biotic and abiotic factors.
  • Example: Bees pollinating flowers is part of their specific niche.
• Food Chain: A linear pathway illustrating energy flow from one organism to another.
• Food Web: A complex network of interconnected food chains, showing multiple feeding relationships within an ecosystem.
• Trophic Levels: Levels within a food chain or web, representing different positions in energy transfer.
• Energy Pyramid: A visualization of decreasing energy transfer with each trophic level.

Chapter 4: Population Dynamics

• Population: A group of individuals of the same species that live in a given area and interact.
• Population Size: The number of individuals in a population.
• Carrying Capacity: The maximum population size an environment can sustain, given available resources.

Chapter 5: Ecosystem Change

• Succession: The process of ecosystem development, with changes over time and in species compositions.
• Primary Succession: Ecosystem development starting on bare rock, with no initial soil.
• Secondary Succession: Ecosystem reconstruction in areas with existing soil, post-disturbance.
• Sampling Methods: Techniques to estimate populations (e.g., quadrat sampling, mark-recapture).

Chapter 6: Cells and Their Environment

• Homeostasis: Maintaining a stable internal environment within an organism despite external changes.
  • Example: Regulating human body temperature.
• Diffusion: Movement of particles from high to low concentration.
• Osmosis: The movement of water across a membrane from an area of low solute concentration to an area of high solute concentration.
• Solutions:
  • Hypertonic: Higher solute, water moves out of cells; cells shrink.
  • Hypotonic: Lower solute, water moves into cells; cells swell.
  • Isotonic: Equal solute, no net water movement; cells maintain shape.
• Endocytosis: Process of taking large molecules into cells by engulfing them.
• Exocytosis: Process of expelling large molecules from cells by merging vesicles with the membrane.

Chapter 7: Cellular Respiration and Energy Transformation

• ATP: The primary energy carrier in cells. ATP releases energy when its phosphate bonds break.
• Cellular Respiration: A process cells use to produce ATP through breaking down glucose or other molecules.
  • Aerobic respiration: Requires oxygen, produces high amounts of ATP.
  • Anaerobic respiration: Does not require oxygen, produces less ATP and byproducts like lactic acid or ethanol.

Chapter 8: Cells - Ch 8

• Cell Organelles and Functions:
  • Nucleus: Control center, contains DNA.
  • Mitochondria: Generate ATP through cellular respiration.
  • Endoplasmic Reticulum (ER): Modifies proteins or synthesizes lipids.
  • Golgi Apparatus: Processes or packages proteins for transport.
  • Ribosomes: Site of protein synthesis.

Chapter 9: Membranes and Transport - Ch 9

• Plasma Membrane Components and Function:
  • Phospholipid Bilayer: Barrier that regulates substance passage.
  • Proteins: Channel, carrier, and receptor proteins facilitate substance transport.
• Passive Transport: Movement of substances across a membrane without energy use. (e.g., diffusion, osmosis).
• Active Transport: Movement of substances against a concentration gradient, requiring energy (e.g., sodium-potassium pump).

Chapter 10: Enzymes, Photosynthesis, and Respiration - Ch 10

• Enzymes: Biological catalysts that speed up biochemical reactions by lowering activation energy.
• Enzyme Function: Lock-and-key model: The active site fits the specific substrate (molecule it acts upon).
• Induced Fit Model: The enzyme's active site changes shape to accommodate substrate.
• Metabolism: Biochemical reactions within living organisms.
  • Catabolism: Breaking down complex molecules.
  • Anabolism: Building complex molecules.

Chapter 11: Animal Systems - Ch 12

• Circulatory Systems:
  • Single Circulatory System: Blood passes through the heart once during circulation (e.g., fish).
  • Double Circulatory System: Blood passes through the heart twice (e.g., mammals).
• Open Circulatory System: Blood (hemolymph) bathes organs directly; pressure is low.
• Closed Circulatory System: Blood travels through vessels; pressure is high.

Chapter 13: Plant Systems - Ch 13

• Vascular Plants:
  • Xylem: Transports water and minerals.
  • Phloem: Transports sugars.
• Stomata and Guard Cells: Pores and surrounding cells regulating gas exchange and water loss.