Unit 1: Climate Change

Unit 1: Climate Change

• Greenhouse Gases (Most Impactful):

  • Carbon Dioxide (CO₂): Primarily from burning fossil fuels & deforestation. Leading human-caused greenhouse gas.
  • Methane (CH₄): Potent greenhouse gas, from livestock, landfills, and agriculture.
  • Nitrous Oxide (N₂O): Released largely from agriculture (fertilizers) and industry (waste).
  • Fluorinated Gases: Synthetic gases used industrially in refrigerants, solvents. High global warming potential.

• Major Methane Sources:

  • Agriculture (livestock digestion, mainly cattle).
  • Landfills (organic waste decomposition).
  • Fossil Fuel Extraction (leaks during production/transport).
  • Wetlands (natural decomposition processes in waterlogged soils).

• Climate Change Problem/Solution:

  • Problem: Global warming due to excess CO₂.
  • Severity: Rising temperatures lead to ice melt, extreme weather, sea-level rise, and harm biodiversity/human life.
  • Solution: Transition to renewable energy.
    • Renewable Energy (Examples): Solar, Wind, Hydroelectric.
    • Impact: Reduced dependence on fossil fuels lowers CO₂ emissions, and thus global warming.
    • Benefits of Renewable Energy: Sustainable & clean, decreases greenhouse gases, and mitigates climate change impacts.

Unit 2: Biology

• Cell Division:

  • Purpose: Growth, repair, and reproduction.
  • Human Chromosome Count: 46 (23 pairs) in most cells.
  • Daughter Cells: Identical cells from a single parent cell.

• Genetics Concepts:

  • DNA: Carries genetic instructions.
  • Chromosome: Thread-like structure of DNA in the nucleus.
  • Gene: Segment of DNA coding for traits/proteins.

• Mitosis Stages:

  • Interphase: Cell preparation (G1, S, G2 phases).
  • Prophase: Chromosomes condense, nuclear membrane dissolves.
  • Metaphase: Chromosomes line up at the cell's center.
  • Anaphase: Chromosomes pulled towards opposite poles.
  • Telophase: New nuclear membranes form.
  • Cytokinesis: Cytoplasm divides, making two separate cells.

• Cell Types - Organelles (Plant & Animal):

  • Plant Cells: Cell wall, chloroplasts (photosynthesis), large central vacuole.
  • Animal Cells: No cell wall, no chloroplasts, small/no vacuoles, rough/smooth ER, Golgi apparatus, lysosomes.

• Plant vs. Animal Cell Differences:

  • Cell wall (plants only).
  • Chloroplasts (plants only).
  • Large central vacuole (plants only).

• Tissues & Organs:

  • Tissue Types: Epithelial, Connective, Muscle, Nervous.
  • Organization Levels: Cells → Tissues → Organs → Organ Systems.
  • Example: Blood (connective tissue) → Heart (organ) → Circulatory system (organ system).

• Organ Systems in Humans:

  • Circulatory System: Transports oxygen, nutrients, waste.
  • Respiratory System: Facilitate gas exchange.
  • Digestive System: Breaks down food for absorption.

Unit 3: Chemistry

• Atomic Structure:

  • Neutron: Neutral particle in the nucleus.
  • Proton: Positive particle in nucleus.
  • Electron: Negative particle orbiting the nucleus.
  • Ion: Atom with a charge (gained/lost electrons).
    • Cation: Positive ion (lost electrons);
    • Anion: Negative ion (gained electrons).

• Atomic Mass: Sum of protons and neutrons.

• Bohr Rutherford Diagram: Shows electron arrangement in energy levels around the nucleus.

• Ionic Compound Formation: Example: Na⁺ + Cl⁻ → NaCl (sodium chloride).

• Periodic Table:

  • Metals: Left/center, tend to lose electrons.
  • Nonmetals: Right, tend to gain electrons.
  • Metalloids: Combination of metal/nonmetal properties.

• Types of Compounds:

  • Ionic Compounds: Metals transfer electrons to nonmetals (NaCl).
  • Polyatomic Compounds: Contain multiple elements grouped together (Na₂CO₃).
  • Molecular Compounds: Nonmetals share electrons (CO₂).

• Stable Octet Rule: Atoms bond to have 8 electrons in outer shell.

• Nomenclature:

  • Ionic Compounds: Metal first, nonmetal with -ide ending (NaCl = Sodium chloride).
  • Molecular Compounds: Use prefixes (CO₂ = Carbon dioxide).

• Balancing Chemical Equations:

  • Law of Conservation: Number of atoms remains same on both sides.

• Types of Chemical Reactions:

  • Synthesis: A + B → AB
  • Decomposition: AB → A + B
  • Single Displacement: A + BC → AC + B
  • Double Displacement: AB + CD → AD + CB

• Acids & Bases:

  • Acid: Donates H⁺ ions (HCl).
  • Base: Accepts H⁺ or donates OH⁻ ions (NaOH).
  • Naming Acids: Hydrochloric acid (HCl), sulfuric acid (H₂SO₄).
  • Naming Bases: Sodium hydroxide (NaOH).
  • pH Scale: Measures acidity/alkalinity (0-7 acidic , 7 neutral, 8-14 basic).

Explore the impacts of greenhouse gases on climate change in this quiz. Understand the major sources of methane and their contributions to global warming. Learn about the severity of climate change and potential solutions to mitigate its effects.