UPCAT Biology — Basic Life Functions & The CellCheat Sheet
Basic Life Functions & The Cell cheat sheet for UPCAT aspirants. If you could only take one sheet of paper into your review session, this is what it would look like. University of the Philippines's most-tested concepts, all in one place.
Exam context
On the UPCAT 2026, the Biology subtest carries a "Core" weight in University of the Philippines's pattern. Basic Life Functions & The Cell lands at position 1st out of 7 in the standard review order. Target score is UPG ≤ 2.2 typical, and roughly 20 items come from Biology on a typical UPCAT paper.
Basic Life Functions & The Cell - Cheat sheet
Your last-minute revision companion for Basic Life Functions & The Cell - all the key facts, processes, and diagrams you need for exam success.
Sections
Section Title
Basic Life Functions (MRS GREN)
Important Facts
- MRS GREN acronym covers all 7 basic life functions
- Excretion differs from egestion (undigested food removal)
- All living things must exhibit ALL seven functions
- Functions work together - nutrition provides energy for movement
Key Definitions
Term
Movement
Example
Blood circulation, muscle contraction, cytoplasmic streaming
Definition
All living organisms exhibit movement at molecular, cellular, or organism level
Term
Respiration
Example
Cellular respiration using glucose and oxygen to produce ATP
Definition
Breakdown of nutrients to release energy for cellular processes
Term
Sensitivity
Example
Plants bending toward light, animals fleeing from danger
Definition
Ability to respond to internal and external stimuli
Term
Growth
Example
Cell division, individual cell enlargement
Definition
Increase in size through anabolic reactions exceeding catabolic reactions
Term
Reproduction
Example
Sexual reproduction (two parents), asexual reproduction (one parent)
Definition
Production of offspring to ensure species survival
Term
Excretion
Example
Urine, sweat, CO2 through breathing (NOT feces - that's egestion)
Definition
Removal of toxic metabolic wastes and excess substances
Term
Nutrition
Example
Autotrophs make food, heterotrophs consume food
Definition
Intake and utilization of nutrients for energy and growth
Diagrams To Know
- MRS GREN concept map showing interconnections
Common Values
Value
Less than 2 micrometers
Symbol
μm
Quantity
Prokaryotic cell size
Value
2 to >100 micrometers
Symbol
μm
Quantity
Eukaryotic cell size
Section Title
Cell Theory & Types
Important Facts
- Robert Hooke - discovered cells in cork
- Schwann (animal cells) and Schleiden (plant cells) - structural/functional units
- Rudolf Virchow - cells arise from pre-existing cells
- Prokaryotes: 70S ribosomes, circular DNA, no mitosis
- Eukaryotes: 80S ribosomes, linear DNA, undergo mitosis
Key Definitions
Term
Cell Theory
Example
All life made of cells, cells from pre-existing cells
Definition
Six principles describing cell properties and behavior
Term
Prokaryotic Cell
Example
Bacteria, Archaea
Definition
Simple cell without membrane-bound nucleus or organelles
Term
Eukaryotic Cell
Example
Plant cells, animal cells, fungi, protists
Definition
Complex cell with membrane-bound nucleus and organelles
Diagrams To Know
- Prokaryotic vs Eukaryotic cell comparison diagram
- Plant vs Animal cell labeled diagrams
Section Title
Cell Organelles & Functions
Important Facts
- Only plants have chloroplasts and cell walls
- Only animals have centrioles and many small vacuoles
- Both have nucleus, mitochondria, ribosomes, ER, Golgi
- Lysosomes common in animals, rare in plants
- Plant cell walls made of cellulose
Key Definitions
Term
Nucleus
Example
Controls cell activities through protein synthesis
Definition
Control center containing genetic material (DNA)
Term
Mitochondria
Example
Cellular respiration occurs here
Definition
Powerhouse of the cell - generates ATP energy
Term
Chloroplast
Example
Contains chlorophyll for capturing light energy
Definition
Site of photosynthesis in plant cells only
Term
Ribosome
Example
70S in prokaryotes, 80S in eukaryotes
Definition
Site of protein synthesis
Term
Endoplasmic Reticulum
Example
RER for proteins, SER for lipids
Definition
Transport system - Rough ER has ribosomes, Smooth ER lacks ribosomes
Diagrams To Know
- Complete animal cell with all organelles labeled
- Complete plant cell with all organelles labeled
- Mitochondria structure showing cristae and matrix
Formulas
Formula
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Meaning
Carbon dioxide + Water → Glucose + Oxygen (using light energy)
Watch Out
Light energy is required - write it above the arrow
When To Use
Overall photosynthesis equation
Common Values
Value
680 nanometers
Symbol
nm
Quantity
P680 wavelength
Value
700 nanometers
Symbol
nm
Quantity
P700 wavelength
Section Title
Photosynthesis
Important Facts
- Occurs in chloroplasts of plant mesophyll cells
- Two stages: Light-dependent (thylakoids) and Light-independent (stroma)
- O₂ is byproduct from water splitting in Photosystem II
- Calvin Cycle needs 3 CO₂ to make 1 G3P
- 6 Calvin cycles needed to make 1 glucose molecule
Key Definitions
Term
Light-Dependent Reaction
Example
Photosystem I and II, chemiosmosis
Definition
Converts light energy to chemical energy (ATP, NADPH) in thylakoids
Term
Calvin Cycle
Example
Carbon fixation, G3P formation, RuBP regeneration
Definition
Light-independent reaction fixing CO₂ into glucose in stroma
Term
Photosystem II
Example
Water splitting releases O₂
Definition
First light-capturing complex using P680 chlorophyll
Term
Photosystem I
Example
Reduces NADP⁺ to NADPH
Definition
Second light-capturing complex using P700 chlorophyll
Diagrams To Know
- Chloroplast structure showing thylakoids and stroma
- Light-dependent reaction showing both photosystems
- Calvin Cycle showing 3 phases
Reactions Or Equations
Note
Source of oxygen released during photosynthesis
Equation
2H₂O → 4H⁺ + 4e⁻ + O₂
Conditions
Photolysis in Photosystem II
Note
NADPH used in Calvin Cycle
Equation
NADP⁺ + H⁺ + 2e⁻ → NADPH
Conditions
End of light-dependent reactions
Formulas
Formula
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Meaning
Glucose + Oxygen → Carbon dioxide + Water + Energy
Watch Out
This is opposite of photosynthesis
When To Use
Overall cellular respiration equation
Common Values
Value
32-38 ATP
Symbol
ATP
Quantity
ATP yield from 1 glucose
Section Title
Cellular Respiration
Important Facts
- Total yield: 32-38 ATP per glucose molecule
- Glycolysis is anaerobic, other stages need oxygen
- NADH yields 2.5-3 ATP, FADH₂ yields 1.5-2 ATP
- 4 protein complexes in electron transport chain
- Water is final electron acceptor product
Key Definitions
Term
Glycolysis
Example
10-step process, anaerobic
Definition
Breakdown of glucose to pyruvate in cytoplasm, produces 2 ATP net
Term
Pyruvate Oxidation
Example
Decarboxylation, oxidation, CoA attachment
Definition
Conversion of pyruvate to acetyl CoA in mitochondria
Term
Krebs Cycle
Example
Citric Acid Cycle, releases 2 CO₂ per cycle
Definition
8-step cycle in mitochondrial matrix producing NADH, FADH₂, ATP
Term
Oxidative Phosphorylation
Example
32-34 ATP produced in inner mitochondrial membrane
Definition
Electron transport chain and chemiosmosis producing most ATP
Diagrams To Know
- Complete cellular respiration overview
- Glycolysis pathway with 10 steps
- Electron transport chain with 4 complexes
Reactions Or Equations
Note
Net gain of 2 ATP
Equation
Glucose + 2 ATP → 2 Pyruvate + 4 ATP + 2 NADH
Conditions
Glycolysis in cytoplasm
Note
Entry into mitochondria
Equation
2 Pyruvate → 2 Acetyl CoA + 2 NADH + 2 CO₂
Conditions
Pyruvate oxidation
Section Title
Cell Reproduction
Important Facts
- Mitosis: PMAT (Prophase, Metaphase, Anaphase, Telophase)
- Meiosis has two divisions: Meiosis I and II
- Crossing over increases genetic diversity
- Binary fission in prokaryotes - simpler than mitosis
- Chromosomes condense in prophase, separate in anaphase
Key Definitions
Term
Mitosis
Example
Growth, repair, asexual reproduction
Definition
Division producing two identical diploid cells
Term
Meiosis
Example
Sexual reproduction, crossing over
Definition
Division producing four genetically different haploid gametes
Term
Cell Cycle
Example
DNA replication in S phase
Definition
Interphase (G1, S, G2) and M phase (mitosis/meiosis + cytokinesis)
Term
Crossing Over
Example
Occurs in Prophase I of meiosis
Definition
Exchange of genetic material between homologous chromosomes
Diagrams To Know
- Mitosis phases showing chromosome behavior
- Meiosis I and II showing crossing over
- Cell cycle diagram with checkpoints
- Chromosome structure with chromatids and centromere
Must Remember
- MRS GREN - all 7 basic life functions must be present in living things
- Cell Theory: All life made of cells, cells are basic units, cells from pre-existing cells
- Prokaryotes have NO nucleus, Eukaryotes HAVE nucleus
- Photosynthesis equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (with light energy)
- Cellular respiration equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
- Mitosis produces 2 identical diploid cells, Meiosis produces 4 different haploid cells
- Only plants have chloroplasts and cell walls, only animals have centrioles
- Glycolysis occurs in cytoplasm (anaerobic), Krebs cycle in mitochondrial matrix
- Light-dependent reactions in thylakoids, Calvin cycle in stroma
- Crossing over occurs in Prophase I of meiosis, increases genetic diversity
Last Minute Tips
- Remember P680 and P700 numbers - they're the wavelengths that each photosystem absorbs best
- Excretion removes metabolic wastes (urine, sweat), Egestion removes undigested food (feces)
- Calvin Cycle needs 6 turns to make 1 glucose (6 carbons), not 3
- In electron transport chain, water is the FINAL electron acceptor, not oxygen gas
- Binary fission is prokaryotic reproduction - much simpler than mitosis/meiosis
Comparison Tables
Rows
Values
- Absent
- Present
Property
Nucleus
Values
- No membrane-bound
- Membrane-bound present
Property
Organelles
Values
- 70S
- 80S
Property
Ribosomes
Values
- Circular, free-floating
- Linear, in nucleus
Property
DNA
Values
- Binary fission
- Mitosis/Meiosis
Property
Cell division
Values
- <2 μm
- 2-100+ μm
Property
Size
Columns
- Property
- Prokaryotic
- Eukaryotic
Table Title
Prokaryotic vs Eukaryotic Cells
Rows
Values
- Present
- Absent
Property
Cell wall
Values
- Present
- Absent
Property
Chloroplasts
Values
- Absent
- Present
Property
Centrioles
Values
- Rare
- Common
Property
Lysosomes
Values
- One large
- Many small
Property
Vacuoles
Columns
- Structure
- Plant Cell
- Animal Cell
Table Title
Plant vs Animal Cells
Rows
Values
- Growth, repair
- Sexual reproduction
Property
Purpose
Values
- 1
- 2
Property
Number of divisions
Values
- 2 diploid
- 4 haploid
Property
Daughter cells
Values
- Identical
- Different
Property
Genetic variation
Values
- No
- Yes (Prophase I)
Property
Crossing over
Columns
- Property
- Mitosis
- Meiosis
Table Title
Mitosis vs Meiosis
Rows
Values
- Chloroplasts
- Mitochondria
Property
Location
Values
- CO₂ + H₂O
- C₆H₁₂O₆ + O₂
Property
Reactants
Values
- C₆H₁₂O₆ + O₂
- CO₂ + H₂O + ATP
Property
Products
Values
- Stores energy
- Releases energy
Property
Energy
Values
- Plants only
- All living things
Property
Organisms
Columns
- Property
- Photosynthesis
- Cellular Respiration
Table Title
Photosynthesis vs Cellular Respiration
Ready to practise for the UPCAT 2026?
Super Tutor's AI review plan adapts to your weak areas and builds a weekly practice schedule around your target UPCAT exam date.