Science
"USTET Science? It's heavy on Bio and Chem. Don't cram this part! UST has strong science programs, so expect thorough testing on fundamental concepts!"
1. Biology - Life Sciences π§¬
USTET Biology covers cell structure, genetics, and body systems. These are the foundational concepts you must know!
Cell Structure & Function
| Organelle | Function | Memory Tip |
|---|---|---|
| Nucleus | Control center, contains DNA | "Brain" of the cell |
| Mitochondria | ATP production (energy) | "Powerhouse" of the cell |
| Ribosomes | Protein synthesis | "Protein factory" |
| Endoplasmic Reticulum | Transport, protein folding | "Highway system" |
| Golgi Apparatus | Packaging, modification | "Post office" |
| Lysosomes | Digestion of waste | "Garbage disposal" |
| Chloroplast | Photosynthesis (plants only) | "Solar panels" |
Genetics Fundamentals
Key Terms
- Gene: Unit of heredity (DNA segment)
- Allele: Different versions of a gene
- Genotype: Genetic makeup (AA, Aa, aa)
- Phenotype: Physical expression
- Dominant: Masks recessive (A > a)
- Recessive: Only shows if homozygous (aa)
Punnett Square Ratios
- Aa x Aa: 3:1 phenotypic ratio
- Aa x aa: 1:1 phenotypic ratio
- AA x aa: All heterozygous (Aa)
- Dihybrid (AaBb x AaBb): 9:3:3:1
Human Body Systems
- Circulatory: Heart pumps blood; arteries (away), veins (toward)
- Respiratory: Lungs exchange O2 and CO2; diaphragm controls breathing
- Digestive: Mouth β Esophagus β Stomach β Small intestine β Large intestine
- Nervous: Brain, spinal cord, nerves; neurons transmit signals
- Excretory: Kidneys filter blood, produce urine
2. Chemistry Essentials π§ͺ
USTET Chemistry focuses on atomic structure, chemical reactions, and stoichiometry.
Atomic Structure
Subatomic Particles
- Proton (+): In nucleus, determines element (atomic number)
- Neutron (0): In nucleus, affects mass (isotopes differ here)
- Electron (-): Orbits nucleus, determines chemical properties
Mass Number = Protons + Neutrons
Atomic Number = Number of Protons = Number of Electrons (neutral atom)
Chemical Bonding
| Bond Type | Description | Example |
|---|---|---|
| Ionic | Metal + Nonmetal (transfer electrons) | NaCl (table salt) |
| Covalent | Nonmetal + Nonmetal (share electrons) | H2O, CO2 |
| Metallic | Metal + Metal (sea of electrons) | Cu, Fe, Au |
| Hydrogen | Weak, between molecules (H attached to F, O, N) | Water molecules |
Balancing Chemical Equations
Steps to Balance
- Write unbalanced equation
- Count atoms on each side
- Add coefficients (NOT subscripts) to balance
- Start with most complex molecule
- Balance hydrogen and oxygen LAST
- Check: same number of each atom on both sides
3. Physics Principles π‘
Physics in USTET covers motion, forces, and energy. Know these fundamental concepts!
Kinematics (Motion)
Key Equations
- v = vβ + at
- d = vβt + (1/2)atΒ²
- vΒ² = vβΒ² + 2ad
- d = ((v + vβ)/2) Γ t
Where: v = final velocity, vβ = initial velocity, a = acceleration, t = time, d = displacement
Newton's Laws of Motion
1st Law: Inertia
Objects at rest stay at rest; objects in motion stay in motion (unless acted upon by force)
2nd Law: F=ma
Force = mass Γ acceleration
More mass = more force needed
3rd Law: Action-Reaction
Every action has an equal and opposite reaction
Energy Concepts
- Kinetic Energy: KE = (1/2)mvΒ² (energy of motion)
- Potential Energy: PE = mgh (stored energy due to position)
- Conservation of Energy: Total energy remains constant (KE + PE = constant)
- Work: W = Fd cos(ΞΈ) (force Γ displacement)
- Power: P = W/t (rate of doing work)
4. Earth Science & Environment π
Basic earth science concepts also appear in USTET!
Rock Types
- Igneous: Cooled magma/lava (granite, basalt)
- Sedimentary: Compressed sediments (limestone, sandstone)
- Metamorphic: Changed by heat/pressure (marble, slate)
Atmosphere Layers
- Troposphere (weather happens here)
- Stratosphere (ozone layer)
- Mesosphere (meteors burn)
- Thermosphere (aurora)
- Exosphere (outer edge)
5. USTET Science Tips π―
Study Strategies
- Understand Concepts: Don't just memorize - understand WHY
- Use Diagrams: Draw cells, body systems, chemical structures
- Practice Calculations: Especially stoichiometry and physics formulas
- Connect Topics: Biology, Chemistry, Physics are interconnected
- Review SHS Lessons: USTET science is based on SHS curriculum
6. Practice Questions π
Q1: What organelle is responsible for ATP production?
Answer: Mitochondria - "Powerhouse of the cell"
Q2: In a Punnett square, if Aa x Aa, what fraction will be homozygous dominant?
Answer: 1/4 or 25% (AA:Aa:aa = 1:2:1)
Q3: A 2kg object accelerates at 3 m/sΒ². What force is applied?
F = ma = 2 Γ 3 = 6 Newtons
Test Your Knowledge! π§
Ready ka na ba? Take the practice quiz for Science to reinforce what you just learned.
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