5.2 Integrated Science: Biology, Chemistry, Physics & Earth Science

Ateneo College Entrance Test ACET

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1 Chapter 1: Mathematics

1.1 Real Numbers, Ratios, Rates & Percentages 1.2 Algebraic Expressions, Polynomials & Linear Equations 1.3 Functions, Domain/Range, Graphs & Transformations 1.4 Quadratic, Polynomial, Exponential & Logarithmic Equations 1.5 Plane Geometry: Triangles, Circles, Polygons & Perimeter/Area 1.6 Coordinate Geometry: Lines, Distance, Midpoints & Conic Sections 1.7 Trigonometry: Right Triangle Ratios, Unit Circle & Basic Identities 1.8 Arithmetic & Geometric Sequences, Series & Word Patterns 1.9 Permutations, Combinations, Probability & Statistics

2 Chapter 2: English Proficiency

2.1 Subject-Verb Agreement, Verb Tenses & Aspect 2.2 Pronoun-Antecedent Agreement, Case, Misplaced & Dangling Modifiers 2.3 Sentence Structure, Run-Ons, Fragments & Parallelism 2.4 Contextual Vocabulary, Word Roots, Prefixes & Suffixes 2.5 Advanced Synonyms, Antonyms & Nuanced Vocabulary 2.6 Verbal Analogies: Relationship Types & Solving Strategies 2.7 Punctuation, Capitalization, Mechanics & Common Errors 2.8 Diction, Idiomatic Expressions, Prepositions & Frequently Confused Words

3 Chapter 3: Reading Comprehension

3.1 Identifying Main Ideas, Central Themes & Paragraph Summaries 3.2 Locating Explicit Details, Supporting Evidence & Data 3.3 Drawing Logical Inferences & Unstated Conclusions 3.4 Analyzing Author's Purpose, Point of View, Tone & Attitude 3.5 Interpreting Figurative Language, Tone Words & Context Clues 3.6 Text Structure, Rhetorical Devices & Evaluating Arguments

4 Chapter 4: Logical and Abstract Reasoning

4.1 Number & Letter Series Patterns & Formulas 4.2 Abstract Reasoning: Matrix Patterns & Figure Rotations 4.3 Formal Syllogisms, Categorical Logic & Deductive Proofs 4.4 Coding-Decoding, Cipher Patterns & Symbol Operations 4.5 Spatial Visualization, Paper Folding & Venn Diagram Logic

5 Chapter 5: General Knowledge

5.1 Philippine History, Government, Constitution & Civics 5.2 Integrated Science: Biology, Chemistry, Physics & Earth Science 5.3 Philippine & World Geography, Basic Economics & Cultural Facts 5.4 Current Events, World Landmarks, Literature & General Trivia

6 Chapter 6: ACET Essay Writing & Exam Strategies

6.1 ACET Essay: Thesis Development, Structuring & Argumentation 6.2 Time Allocation, Pacing Strategies & Subtest Tactics 6.3 Guessing Strategies (No Penalty), Test Anxiety & Exam Day Readiness

5.2 Integrated Science: Biology, Chemistry, Physics & Earth Science

Key Takeaways Explain This Topic AI

Cell biology emphasizes organelle specialization: Mitochondria produce ATP via cellular respiration, Chloroplasts conduct photosynthesis, and Ribosomes synthesize proteins.

Mendelian genetics yields predictable phenotypic ratios, such as the 3:1 ratio in a monohybrid cross of heterozygous dominant parents (Aa x Aa).

The periodic table displays predictable periodic trends: Electronegativity and Ionization Energy increase up and to the right, whereas Atomic Radius increases down and to the left.

Newton's Three Laws of Motion govern classical mechanics: Inertia (1st Law), F = ma (2nd Law), and Action-Reaction (3rd Law).

Plate tectonics drives geological processes along convergent, divergent, and transform boundaries, while atmospheric dynamics dictate weather patterns in the Troposphere.

Last updated: July 2026

Integrated Science: Biology, Chemistry, Physics & Earth Science

The General Science component of the ACET spans four major scientific disciplines. Success requires a firm grasp of core vocabulary, foundational equations, biological structures, chemical reactions, physical laws, and Earth system processes.

1. Biological Sciences
Cell Biology & Organelles

All living organisms are composed of cells—prokaryotes (lacking a membrane-bound nucleus, e.g., bacteria) or eukaryotes (containing membrane-bound organelles, e.g., plants, animals, fungi).

Organelle Function Key Characteristic
Nucleus Stores genomic DNA and controls cellular activity Surrounded by a double-membrane nuclear envelope

Mitochondria Generates cellular energy (ATP) via aerobic respiration Known as the "powerhouse of the cell"; contains own mtDNA

Ribosomes Site of protein synthesis (translation) Found free in cytoplasm or bound to Rough ER

Endoplasmic Reticulum (ER) Rough ER: protein folding/transport; Smooth ER: lipid synthesis & detoxification Interconnected network of tubules and sacs

Golgi Apparatus Modifies, sorts, and packages proteins for secretion Stacks of flattened sacs (cisternae)

Chloroplasts Converts solar energy into chemical energy (glucose) Present in plants/algae; contains chlorophyll

Bioenergetics: Photosynthesis vs. Respiration

Photosynthesis Equation: 6 CO 2 + 6 H 2 O + Light Energy → Chlorophyll C 6 H 12 O 6 + 6 O 2 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Light Energy} \xrightarrow{\text{Chlorophyll}} \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 6 CO 2 + 6 H 2 O + Light Energy Chlorophyll C 6 H 12 O 6 + 6 O 2

Cellular Respiration Equation: C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + 36 – 38 ATP \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + 36\text{--}38\text{ ATP} C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + 36 – 38 ATP Respiration occurs in three stages: Glycolysis (cytoplasm, anaerobic, net 2 ATP), Krebs Cycle (mitochondrial matrix, 2 ATP), and Oxidative Phosphorylation / Electron Transport Chain (inner mitochondrial membrane, ~32–34 ATP).

Genetics & Inheritance

Gregor Mendel's Laws of Inheritance:

Monohybrid Cross ( A a × A a Aa \times Aa A a × A a ): Produces a 3:1 phenotypic ratio (Dominant : Recessive) and a 1:2:1 genotypic ratio ( 1 A A : 2 A a : 1 a a 1 AA : 2 Aa : 1 aa 1 AA : 2 A a : 1 aa ).

Dihybrid Cross ( A a B b × A a B b AaBb \times AaBb A a B b × A a B b ): Produces a 9:3:3:1 phenotypic ratio .

Central Dogma: DNA → Transcription \xrightarrow{\text{Transcription}} Transcription RNA → Translation \xrightarrow{\text{Translation}} Translation Protein. DNA uses bases A, T, C, G; RNA replaces Thymine with Uracil (U) .

2. Chemical Sciences
Atomic Structure & Periodic Trends

Subatomic Particles: Protons ( p + p^+ p + , + 1 +1 + 1 charge, mass ≈ 1 amu \approx 1\text{ amu} ≈ 1 amu ), Neutrons ( n 0 n^0 n 0 , neutral, mass ≈ 1 amu \approx 1\text{ amu} ≈ 1 amu ), Electrons ( e − e^- e − , − 1 -1 − 1 charge, negligible mass).

Atomic Number ( Z Z Z ): Number of protons (defines the element). Mass Number ( A A A ): Protons + + + Neutrons. Periodic Table Trends:

Increase Electronegativity & Ionization Energy --->
+--------------------------------------------------+
| | ^
| | |
| | |
+--------------------------------------------------+
Increase Atomic Radius <--- | Downward Increase v

Electronegativity: The ability of an atom to attract shared electrons in a bond (Fluorine is the most electronegative element).

Ionization Energy: Energy required to remove an electron from a gaseous atom.

Atomic Radius: Distance from nucleus to valence shell; decreases across a period (left to right) and increases down a group.

Bonding & pH Scale

Ionic Bonding: Transfer of electrons from a metal (cation) to a nonmetal (anion), e.g., NaCl \text{NaCl} NaCl .

Covalent Bonding: Sharing of electron pairs between nonmetal atoms, e.g., H 2 O , CO 2 \text{H}_2\text{O}, \text{CO}_2 H 2 O , CO 2 .

pH Scale: Logarithmic scale measuring hydrogen ion concentration: pH = − log ⁡ [ H + ] \text{pH} = -\log[\text{H}^+] pH = − lo g [ H + ] .

pH < 7 \text{pH} < 7 pH < 7 : Acidic (higher [ H + ] [\text{H}^+] [ H + ] )
pH = 7 \text{pH} = 7 pH = 7 : Neutral (pure water at 25 ∘ C 25^\circ\text{C} 2 5 ∘ C )
pH > 7 \text{pH} > 7 pH > 7 : Basic / Alkaline

Logarithmic Rule: A drop from pH 6 to pH 4 represents a 100-fold ( 10 2 10^2 1 0 2 ) increase in acidity ( [ H + ] [\text{H}^+] [ H + ] ).

3. Physics & Mechanics
Classical Mechanics & Newton's Laws

First Law (Inertia): An object remains at rest or in uniform motion unless acted upon by a net external force.

Second Law ( F = m a F = ma F = ma ): Force equals mass times acceleration ( 1 N = 1 kg ⋅ m/s 2 1\text{ N} = 1\text{ kg}\cdot\text{m/s}^2 1 N = 1 kg ⋅ m/s 2 ).

Third Law (Action-Reaction): For every action, there is an equal and opposite reaction.

Work, Energy & Electricity

Work: W = F ⋅ d ⋅ cos ⁡ θ W = F \cdot d \cdot \cos\theta W = F ⋅ d ⋅ cos θ (measured in Joules, 1 J = 1 N ⋅ m 1\text{ J} = 1\text{ N}\cdot\text{m} 1 J = 1 N ⋅ m ).

Kinetic Energy: K E = 1 2 m v 2 KE = \frac{1}{2} m v^2 K E = 2 1 m v 2 | Potential Energy: P E = m g h PE = m g h PE = m g h .

Law of Conservation of Energy: Total mechanical energy ( K E + P E KE + PE K E + PE ) remains constant in an isolated system without friction.

Ohm's Law: V = I R V = I R V = I R , where V V V is Voltage (Volts), I I I is Current (Amperes), and R R R is Resistance (Ohms Ω \Omega Ω ).

4. Earth & Atmospheric Science
Earth Structure & Plate Tectonics

Earth is divided into Crust, Mantle, Outer Core (liquid iron-nickel driving the magnetic field), and Inner Core (solid iron-nickel).

Convergent Boundaries: Plates collide (subduction zones form deep trenches, volcanic arcs, and mountain ranges like the Himalayas).

Divergent Boundaries: Plates separate (mid-ocean ridges, rift valleys).

Transform Boundaries: Plates slide past each other horizontally (cause shallow earthquakes along fault lines like the Marikina Valley Fault System).

Atmospheric Layers & Weather Events

Troposphere: Lowest layer containing 75% of atmospheric mass; all weather phenomena occur here .

Stratosphere: Contains the Ozone Layer ( O 3 \text{O}_3 O 3 ), which absorbs harmful ultraviolet (UV-B and UV-C) solar radiation.

El Niño vs. La Niña: El Niño is the anomalous warming of sea surface temperatures in the central/eastern tropical Pacific, causing prolonged droughts in the Philippines. La Niña involves anomalous cooling, bringing heavy rainfall and flooding.