science

• Tectonic Plates


  • Large slabs of Earth's lithosphere that fit together like a jigsaw puzzle
• Types of Plate Boundaries

  • Divergent Boundaries
  • Convergent Boundaries
  • Transform Fault Boundaries
• Divergent Boundaries


  Plates move apart. Example: Mid-Atlantic Ridge
• Convergent Boundaries


  Plates move towards each other. Example: Himalayas
• Transform Fault Boundaries


  Plates slide past each other horizontally. Example: San Andreas Fault
• Plate Movement


  1. Driven by mantle convection

  2. Slab pull

  3. Ridge push
• Types of Convergent Boundaries

  • Oceanic-continental: subduction zones, volcanic arcs
  • Oceanic-oceanic: island arcs, deep ocean trenches
  • Continental-continental: mountain ranges (e.g., Himalayas)
• Transform Fault Boundaries


  • Earthquake activity
  • No significant vertical movement
  • Example: San Andreas Fault in California
• Pangaea


  Supercontinent that existed about 335 million years ago
• Evidence for Pangaea


  • Fossil distribution
  • Rock formations
  • Glacial deposits
• Pangaea started to break apart about 175 million years ago, leading to the formation of current continents
• Basic Physics Concepts


  • Mechanics: Study of motion and forces
  • Energy: Capacity to do work
  • Waves: Disturbances that transfer energy through matter or space
• Newton's Laws of Motion

  • First Law (Inertia): An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force
  • Second Law (F=ma): Force equals mass times acceleration
  • Third Law: For every action, there is an equal and opposite reaction
• Cell Division


  • Mitosis: Division of a somatic cell into two genetically identical daughter cells
  • Meiosis: Division of a germ cell into four genetically diverse gametes
• Mitosis Phases


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase

  5. Cytokinesis
• Meiosis Phases


  1. Meiosis I (reduction division)

  2. Meiosis II (equational division)
• DNA


  Deoxyribonucleic acid, carries genetic information
• DNA Structure


  • Double helix
• DNA Bases


  • Adenine (A)
  • Thymine (T)
  • Cytosine (C)
  • Guanine (G)
• RNA


  Ribonucleic acid, involved in protein synthesis
• RNA Types


  • mRNA (messenger)
  • tRNA (transfer)
  • rRNA (ribosomal)
• RNA Bases


  • Adenine (A)
  • Uracil (U)
  • Cytosine (C)
  • Guanine (G)
• XX Chromosomes


  Female sex chromosomes
• XY Chromosomes


  Male sex chromosomes
• Gender Determination


  The presence of a Y chromosome typically determines male sex
• Covalent Bonds


  Sharing of electron pairs between atoms
• Covalent Bond Example


  • H2O (water)
• Ionic Bonds


  Transfer of electrons from one atom to another, resulting in oppositely charged ions
• Ionic Bond Example

  • NaCl (table salt)
• Common Chemical Symbols


  • H: Hydrogen
  • O: Oxygen
  • Na: Sodium
  • Cl: Chlorine
  • C: Carbon
• The principle behind balancing chemical equations is the Law of Conservation of Mass (matter is neither created nor destroyed)
• Covalent bonding involves the sharing of electrons between atoms, forming molecules with strong bonds.
• Ionic bonding occurs when electrons are transferred from one atom to another, resulting in the formation of positively charged ions and negatively charged ions that attract each other.
• The three types of chemical bonds are ionic, covalent, and metallic.
• Metallic bonding is characterized by the attraction between positive metal ions and delocalized electrons within a lattice structure.
• Metallic bonding involves the attraction between positive metal ions and delocalized electrons, holding them together in a lattice structure.