1. Biology - The Study of Life 🧬
Cell Biology
Animal Cell
- Cell Membrane: Selectively permeable
- Nucleus: Control center (DNA)
- Mitochondria: Powerhouse (ATP)
- Ribosomes: Protein synthesis
- Centrioles: Cell division
Plant Cell (Additional)
- Cell Wall: Rigid structure (cellulose)
- Chloroplast: Photosynthesis
- Large Vacuole: Storage, turgor pressure
- Plasmodesmata: Cell communication
🧬 DNA & Genetics
DNA Structure: Double helix, A-T, G-C base pairs
Replication: Semi-conservative (each strand as template)
Transcription: DNA → mRNA (in nucleus)
Translation: mRNA → Protein (at ribosome)
Mendel's Laws:
- Law of Dominance
- Law of Segregation
- Law of Independent Assortment
| Process | Location | Formula/Product |
|---|---|---|
| Photosynthesis | Chloroplast | 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ |
| Cellular Respiration | Mitochondria | C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP |
| Mitosis | Somatic cells | 2n → 2n (2 identical diploid cells) |
| Meiosis | Gametes | 2n → n (4 haploid cells) |
2. Chemistry - The Central Science ⚗️
Atomic Structure & Periodic Table
Subatomic Particles
- Proton: +1 charge, in nucleus (atomic #)
- Neutron: 0 charge, in nucleus (mass #)
- Electron: -1 charge, orbits nucleus
Periodic Trends
- Atomic Radius: ↓ across period, ↑ down group
- Electronegativity: ↑ across, ↓ down (F highest)
- Ionization Energy: ↑ across, ↓ down
🔗 Chemical Bonds
- Ionic: Metal + Nonmetal (electron transfer)
- Covalent: Nonmetal + Nonmetal (electron sharing)
- Metallic: Metal + Metal (electron sea)
- Hydrogen: H bonded to F, O, N (intermolecular)
⚖️ Balancing Equations
Law of Conservation of Mass: Matter cannot be created or destroyed.
Example:
H₂ + O₂ → H₂O
2H₂ + O₂ → 2H₂O ✓
🧪 Acids & Bases
| Property | Acid | Base |
|---|---|---|
| pH | < 7 | > 7 |
| Taste | Sour | Bitter |
| Litmus | Blue → Red | Red → Blue |
| Arrhenius | Produces H⁺ | Produces OH⁻ |
3. Physics - Laws of Nature 🚀
Newton's Laws of Motion
1st Law: Law of Inertia
An object at rest stays at rest; an object in motion stays in motion unless acted upon by an external force.
Example: Seatbelts - body continues moving when car stops suddenly
2nd Law: F = ma
Force equals mass times acceleration. More mass = more force needed.
Example: Pushing empty cart vs full cart
3rd Law: Action-Reaction
For every action, there is an equal and opposite reaction.
Example: Rocket propulsion, swimming
⚡ Energy
- Kinetic (KE): ½mv² (energy of motion)
- Potential (PE): mgh (stored energy)
- Law of Conservation: Energy cannot be created or destroyed, only transformed
🌊 Waves
- Transverse: Perpendicular (light, water)
- Longitudinal: Parallel (sound)
- v = fλ (velocity = frequency × wavelength)
🔌 Electricity & Magnetism
Ohm's Law: V = IR
Power: P = IV = I²R = V²/R
Series: Same current, R total = R₁ + R₂
Parallel: Same voltage, 1/R = 1/R₁ + 1/R₂
Electromagnetic Spectrum:
Radio → Microwave → Infrared → Visible → UV → X-ray → Gamma
(Increasing frequency & energy →)
4. Earth Science 🌍
Earth's Structure
Inner Core
Solid iron-nickel
Hottest layer
Outer Core
Liquid iron-nickel
Creates magnetic field
Mantle
Semi-solid rock
Convection currents
Crust
Solid rock
Continental & Oceanic
🌋 Plate Tectonics
- Convergent: Plates collide (mountains, trenches)
- Divergent: Plates separate (mid-ocean ridges)
- Transform: Plates slide past (earthquakes)
- Ring of Fire: Pacific plate boundaries (PH included!)
🌧️ Weather vs Climate
- Weather: Short-term atmospheric conditions
- Climate: Long-term weather patterns
- Factors: Latitude, altitude, proximity to water, ocean currents
🪨 Rock Cycle
| Rock Type | Formation | Examples |
|---|---|---|
| Igneous | Cooling of magma/lava | Granite (intrusive), Basalt (extrusive) |
| Sedimentary | Compaction & cementation | Sandstone, Limestone, Shale |
| Metamorphic | Heat & pressure transformation | Marble (from limestone), Slate (from shale) |
5. Scientific Method & Inquiry 🔬
Steps of the Scientific Method
1. Observation
Notice a phenomenon
2. Question
Ask "why" or "how"
3. Hypothesis
Educated prediction (If...then)
4. Experiment
Test hypothesis (control variables)
5. Data Analysis
Collect and interpret results
6. Conclusion
Accept or reject hypothesis
📊 Variables
- Independent: What you CHANGE (manipulated)
- Dependent: What you MEASURE (responding)
- Controlled: What you KEEP THE SAME
🎯 Types of Inquiry
- Structured: Teacher provides question & procedure
- Guided: Teacher provides question only
- Open: Student-driven (most autonomy)
6. Science Teaching Strategies 👩🔬
| Strategy | Description | Best For |
|---|---|---|
| 5E Model | Engage → Explore → Explain → Elaborate → Evaluate | Inquiry-based learning |
| POE | Predict → Observe → Explain | Demonstrations, conceptual change |
| Lab Work | Hands-on experimentation | Process skills, scientific method |
| STS Approach | Science-Technology-Society connections | Real-world applications, values |
🔬 Science Process Skills:
📋 Practice Questions
1. What is the powerhouse of the cell?
Show Answer
Mitochondria - produces ATP through cellular respiration.
2. What type of bond is formed between Na and Cl in NaCl?
Show Answer
Ionic bond - electron transfer from metal (Na) to nonmetal (Cl).
3. According to Newton's 2nd Law, if mass doubles while force stays constant, what happens to acceleration?
Show Answer
Acceleration is halved. F = ma, so a = F/m. If m doubles, a is divided by 2.
4. What type of plate boundary creates mountains like the Himalayas?
Show Answer
Convergent boundary (continental-continental collision).
5. In the 5E Model, which phase comes after "Explore"?
Show Answer
Explain - where students articulate their understanding and teacher clarifies concepts.
🎯 Exam Strategy Tips
🧬 Biology
Memorize cell parts and their functions. Know photosynthesis vs cellular respiration formulas. Understand Mendel's laws.
⚗️ Chemistry
Know periodic trends (atomic radius, electronegativity). Understand bond types. Practice balancing equations.
🚀 Physics
Newton's Laws are ALWAYS asked. Know formulas: F=ma, KE=½mv², v=fλ, V=IR. Practice problem solving.
🌍 Earth Science
Know Earth's layers and plate boundaries. Understand rock cycle. Philippines is in the Ring of Fire!
🔬 Scientific Method
Variables: Independent (change), Dependent (measure), Controlled (constant). Know the steps in order.
👩🔬 Teaching Strategies
5E Model: Engage-Explore-Explain-Elaborate-Evaluate. Know process skills and inquiry types.
Science Major = Bio + Chem + Physics + Earth Sci + Pedagogy. Integration is key! 🔬