Middle School End of Course Review - Earth Science

Earth and Space

  • Planets:
    • Inner (terrestrial) planets are between the Sun and asteroid belt.
    • Outer (gas giants) are beyond the asteroid belt.
  • Earth's Movements:
    • Rotation: 24 hours, causes day/night, spins on axis.
    • Revolution: 1 year, circular movement, causes seasons, moves in orbit.
  • Seasons:
    • Determined by Earth's position relative to the Sun.
  • Gravity:
    • Jupiter has the fastest acceleration due to gravity, Earth the slowest based on provided chart.
  • Celestial Objects:
    • Comet: Big ball of dirty ice and snow.
    • Asteroid: Small body between Mars and Jupiter.
    • Satellite: Body or moon orbiting a planet.
  • Eclipses:
    • Lunar: Earth between Sun and Moon, blocking the Moon.
    • Solar: Moon between Earth and Sun, blocking the Sun.
  • Tides:
    • Spring: Moon, Sun, and Earth aligned; highest high tides.
    • Neap: Moon and Sun at 90° angles to Earth; lowest low tides.
  • Moon Phases:
    • Different phases are visible as the Moon revolves around Earth.

Earth's Resources

  • Renewable resources can be replenished quickly (e.g., hydropower, wind, solar).
  • Nonrenewable resources are limited and cannot be replenished quickly (e.g., natural gas, coal, petroleum).
  • Protecting air quality is important; burning fossil fuels can cause acid rain.

Water

  • Water Cycle:
    • Evaporation: Liquid to vapor.
    • Transpiration: Evaporation from plants.
    • Condensation: Water vapor cools and forms liquid.
    • Precipitation: Rain, snow, sleet, or hail.
    • Infiltration: Water soaking into the ground.
    • Runoff: Water flowing across the land.
  • Water is a universal solvent.
  • Liquid water density: 1
    ewline g/mL. Ice is less dense, allowing it to float.
  • Weathering
    • Physical Wheathering
    • Chemical Weathering: Rust
  • Water Properties:
    • Cohesion: Water clings to water.
    • Adhesion: Water clings to other substances.
  • Oceans contain 97% of Earth's salt water.
  • Only 1% of Earth's fresh water is non-frozen and available.

Atmosphere

  • Atmospheric Layers:
    • Troposphere: Closest to Earth, contains most of the atmosphere's mass; weather occurs here. Temperature decreases as altitude increases.
    • Stratosphere: Contains ozone layer.
    • Mesosphere: Coldest layer.
    • Thermosphere: High temperatures due to absorption of sun's rays. Temperature increases as altitude increases.
    • Exosphere: Outermost layer, few air molecules.

Watershed

  • Watershed: Land area where water flows across or through on its way to a stream, lake, or wetland.
  • Drainage basin: The land area from which a river and its tributaries drain.
  • Runoff: Water that flows over the ground.
  • Divide: Ridge of land separating drainage basins.
  • Floodplain: Flat valley through which a river flows.
  • Wetlands: Transition zone between land and water bodies.
  • Alluvial Fan: Wide, sloping deposit where a stream leaves a mountain ridge.
  • Delta: Landform made of sediment at the mouth of a river.
  • Levee: Ridge of sediment alongside a river channel.
  • Tributary: Stream flowing into a larger stream.
  • Estuary: Where fresh and salt water mix.
  • Reservoir: Natural or artificial lake for water storage.
  • Eutrophication: Nutrient buildup in a lake, causing algae growth.
  • Water Quality Tests:
    • Turbidity: Measures water clarity.
    • Dissolved Oxygen: Indicates water's health.
    • Nutrients: Affect dissolved oxygen & biological availability.
    • pH: Affects solubility (phosphorus/nitrogen).
    • Temperature: Influences organisms and dissolved oxygen.
    • Salinity: Controls types of plants and animals.

Clouds/Weather

  • Clouds form when water vapor condenses.
  • Stratus clouds are associated with rain and found at low altitudes.
  • Cumulus clouds are associated with fair weather.
  • Cirrus clouds signal a change in weather.
  • Cloud Types:
    • Cirrus: Formed by ice crystals, wispy appearance.
    • Cumulus: White, fluffy masses with flat bases.
    • Stratus: Low, gray, without definite form, may give winter skies a dull color.
  • Fronts:
    • Warm: Warm air slides over cold air.
    • Cold: Colder air forces warm air upward.
    • Stationary: Neither air mass advances.
    • Occluded: Colder air closes off warm air from Earth's surface.

Cells

  • Cell Theory:
    • All living things are composed of cells.
    • Cells are the smallest unit of life.
    • Living cells come from other living cells.
  • Cell Types:
    • Prokaryotic: Simple, no recognizable organelles.
    • Eukaryotic: Larger, specialized organelles.
  • Cell Structures:
    • Cell Membrane: Keeps cytoplasm inside; allows nutrients in and waste out.
    • Cell Wall: Protects and supports (plants only).
    • Nucleus: Directs cell activities.
    • Mitochondria: Breaks down food molecules for energy.
    • Chloroplast: Captures energy from sunlight (plants only).
    • Endoplasmic Reticulum: Packages proteins for delivery.
    • Golgi Body: Modifies and ships chemical products.
    • Vacuole: Stores water and other liquids.
    • Lysosome: Breaks down substances.
    • Ribosome: Creates proteins.
    • Cytoplasm: Cellular fluid surrounding organelles.
  • Cell Division:
    • Mitosis: Asexual reproduction; single division; two identical daughter cells; occurs in all cells; genetic makeup
    • Meiosis: Sexual reproduction; two divisions; half the number of chromosomes; occurs in gonads (testes/ovaries).
  • Cell Life Cycle:
    • Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.
  • Cellular Organization:
    • Cell -> Tissue -> Organ -> Organ System -> Organism.
  • Life Functions:
    • Respiration, Excretion, Growth, Reproduction.
  • Cellular Transport:
    • Passive Transport: No energy required.
    • Active Transport: Requires energy.
    • Diffusion: Solutes move from high to low concentration.
    • Osmosis: Water moves from high to low concentration.
    • Semipermeable: Allows small particles to enter.

Classification

  • Scientific nomenclature uses genus and species (e.g., Homo sapien).
  • Taxonomic Classification:
    • Domain -> Kingdom -> Phylum -> Class -> Order -> Family -> Genus -> Species
    • Species: Most specific characteristics.
    • Domain: Broadest characteristics.
  • Kingdom Characteristics:
    • Archaebacteria: Prokaryote, unicellular, some autotrophs, some heterotrophs.
    • Bacteria: Prokaryote, unicellular, some autotrophs, some heterotrophs.
    • Protists: Eukaryote, uni (except algae), both.
    • Fungi: Eukaryote, both, heterotroph.
    • Plants: Eukaryote, multicellular, autotroph.
    • Animals: Eukaryote, multicellular, heterotroph.
  • Plant/Animal Phyla:
    • Chordate: Animals with a backbone.
    • Mollusk: Usually unsegmented and soft bodied; have a shell (snails, clams).
    • Annelid: Segmented, soft bodies that have blood and nervous systems (leeches, earthworms).
    • Arthropod: Three body parts, segmented legs and exoskeletons (crabs, spiders).
    • Ferns: Roots, underground stems, and large leaves.

Photosynthesis

  • Process:
    1. Sunlight captured.
    2. Water absorbed by roots.
    3. CO2 enters plant.
    4. O2 released by plant.
  • Formula: CO2 + H2O \rightarrow C6H{12}O6 + O2
    • carbon dioxide + Water (H2O) -> Glucose (C6H12O6) + oxygen