EOC Notes for BIO

🌱 Unit 1: Cells (SB1) – In-Depth Notes for Georgia Biology EOC

🔹 SB1a – Cellular Reproduction (Mitosis) in Growth & Maintenance

🔬 What is Mitosis?

• Purpose: Growth, tissue repair, and asexual reproduction in multicellular organisms.
  
  

• Produces: Two identical diploid (2n) daughter cells.
  
  

• Occurs in: Somatic (body) cells.
  
  

📈 Importance in Growth & Maintenance

• Allows organisms to grow from a single cell.
  
  

• Replaces damaged or old cells (e.g., skin healing).
  
  

• Maintains genetic consistency across cells.
  
  

🌀 Stages of Mitosis

1. Prophase: Chromosomes condense; nuclear envelope dissolves; spindle fibers form.
   
   

2. Metaphase: Chromosomes line up at the cell's equator.
   
   

3. Anaphase: Sister chromatids pulled apart to opposite poles.
   
   

4. Telophase: Nuclear membranes reform; chromosomes begin to uncoil.
   
   

5. Cytokinesis: Cytoplasm divides, forming two identical cells.

(Meiosis 1 and 2)

🔹 SB1b – Mitosis, Meiosis & Differentiation

⚖ Comparison: Mitosis vs. Meiosis

🧬 Meiosis: Generating Genetic Diversity

• Crossing Over: Exchange of genetic material between homologous chromosomes (Prophase I).
  
  

• Independent Assortment: Random alignment of chromosomes (Metaphase I).
  
  

• Essential for sexual reproduction.
  
  

🌟 Differentiation

• Process where unspecialized cells become specialized (e.g., muscle, nerve, blood).
  
  

• Regulated by gene expression.
  
  

• Enables multicellular complexity.
  
  

🔹 SB1c – DNA: Storage of Genetic Information

📚 Structure of DNA

• Double helix made of nucleotides (sugar, phosphate, base).
  
  

• Bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G).
  
  

  • A pairs with T; C pairs with G.
    
    

📦 Function

• Stores instructions for building proteins.
  
  

• DNA → RNA → Protein (central dogma of biology).
  
  

• Packaged into chromosomes in the nucleus.
  
  

🔹 SB1d – Protein Synthesis (DNA to Protein)

🧾 Step 1: Transcription

• Location: Nucleus.
  
  

• DNA is used as a template to make messenger RNA (mRNA).
  
  

• RNA base pairs: A-U, C-G.
  
  

⚙ Step 2: Translation

• Location: Ribosome (in cytoplasm).
  
  

• mRNA is read in codons (3-letter sequences).
  
  

• Each codon codes for one amino acid.
  
  

• tRNA brings correct amino acids to build a polypeptide (protein).
  
  

🔹 SB1e – Enzymes

⚡ What Are Enzymes?

• Biological catalysts that speed up chemical reactions.
  
  

• Mostly proteins.
  
  

🔑 How They Work

• Substrate binds to enzyme’s active site.
  
  

• Follows the lock-and-key or induced fit model.
  
  

🧪 Factors Affecting Enzyme Function

• Temperature: Too high → denaturation; Too low → slow activity.
  
  

• pH: Each enzyme works best at a specific pH.
  
  

• Concentration: More enzyme = faster reaction (to a point).Substrate concentration: Increasing substrate concentration generally increases the rate of reaction until the enzymes become saturated.

🌱 Unit 2: Patterns in Living Systems – In-Depth Notes (Georgia Biology EOC)

🔹 SB2a – Cell Theory

🔬 The 3 Parts of Cell Theory:

1. All living things are made of one or more cells.
   → Even the simplest organisms like bacteria are made of cells.
   
   

2. The cell is the basic unit of structure and function in living organisms.
   → Everything a living thing does (grow, respond, reproduce) happens at the cell level.
   
   

3. All cells come from pre-existing cells.
   → Cells reproduce by dividing (mitosis or binary fission), not spontaneously.
   
   

📜 Historical Contributors:

• Robert Hooke: Named "cells" while looking at cork.
  
  

• Schleiden & Schwann: Proposed plants and animals are made of cells.
  
  

• Virchow: All cells come from existing cells.
  
  

🔹 SB2b – Prokaryotic vs. Eukaryotic Cells

🦠 Examples:

• Prokaryote: E. coli (bacteria)
  
  

• Eukaryote: Human skin cells, plant leaf cells, yeast
  
  

🔹 SB2c – Organelles & Their Functions

🧬 Key Organelles (and what they do):

• Nucleus:
  
  

  • Controls cell activities
    
    

  • Stores DNA (genetic info)
    
    

• Mitochondria:
  
  

  • Site of cellular respiration
    
    

  • Produces ATP (cellular energy)
    
    

• Chloroplast (plants only):
  
  

  • Site of photosynthesis
    
    

  • Uses sunlight to make glucose
    
    

• Ribosomes:
  
  

  • Synthesize proteins
    
    

  • Can float freely or attach to rough ER
    
    

• Endoplasmic Reticulum (ER):
  
  

  • Rough ER: Modifies proteins (has ribosomes)
    
    

  • Smooth ER: Synthesizes lipids & detoxifies
    
    

• Golgi Apparatus:
  
  

  • Packages and ships proteins
    
    

• Vacuole:
  
  

  • Stores water, nutrients, and waste
    
    

  • Larger in plant cells for structure
    
    

• Cell Membrane:
  
  

  • Controls what enters/leaves the cell
    
    

  • Maintains homeostasis
    
    

• Cell Wall (plants only):
  
  

  • Provides structure and protection
    
    

  • Made of cellulose
    
    

• Lysosomes (mostly in animals):
  
  

  • Digest waste & old organelles using enzymes
    
    

🔹 SB2d – Homeostasis & Transport

🧫 What is Homeostasis?

• The process by which cells maintain a stable internal environment.
  
  

• Maintained by the cell membrane controlling movement of materials.
  
  

🌊 Types of Transport Across the Membrane:

1. Passive Transport – No energy required (moves high → low)

• Diffusion: Movement of molecules (like O₂, CO₂) down their concentration gradient.
  
  

• Osmosis: Diffusion of water across a membrane.
  
  

  • Hypertonic: Water moves out → cell shrinks.
    
    

  • Hypotonic: Water moves in → cell swells.
    
    

  • Isotonic: No net water movement.
    
    

• Facilitated Diffusion: Uses protein channels for bigger molecules (like glucose).
  
  

2. Active Transport – Requires energy (ATP) (low → high)

• Moves substances against concentration gradient.
  
  

• Examples: Na⁺/K⁺ pump, endocytosis (in), exocytosis (out).
  
  

🧬 How It All Ties Together:

• Organelles function together (e.g., DNA → mRNA in nucleus → proteins at ribosomes).
  
  

• Cells rely on transport and membrane control to survive.
  
  

• Cell types and structures reflect their role (e.g., muscle cells have more mitochondria).

🧪 SCIENTIFIC METHOD & EXPERIMENTAL DESIGN

Key Concepts:

• Hypothesis: A proposed explanation based on limited evidence. Should be testable and falsifiable. Format: If [independent variable], then [dependent variable], because [rationale].
  
  

• Independent Variable: The condition manipulated by the experimenter (e.g., temperature, pH, light).
  
  

• Dependent Variable: The response measured (e.g., enzyme activity, growth rate).
  
  

• Constants: All variables held the same across all groups to isolate the effect of the independent variable.
  
  

• Control Group: Baseline for comparison; may receive no treatment or a placebo.
  
  

• Experimental Group: Group(s) receiving the changed independent variable.
  
  

Data Interpretation:

• Graphs: Title, axis labels, proper units.
  
  

• Line Graphs: Show trends over time or continuous data.
  
  

• Bar Graphs: Compare categories or groups.
  
  

• Scatterplots: Show correlation.
  
  

• Error Bars: Represent variability (standard deviation or SEM). Overlap indicates a less significant difference.
  
  

• Replication: Increases reliability; reduces impact of outliers.
  
  

🔁 CELLULAR PROCESSES

Photosynthesis:

• Location: Chloroplasts (plants and some protists).
  
  

• Equation:
  6CO₂ + 6H₂O + light energy (from sun) → C₆H₁₂O₆ + 6O₂
  
  

• Light-dependent reactions (in thylakoid membranes):
  
  

  • Use sunlight to split water (photolysis), releasing O₂
    
    

  • Produce ATP and NADPH
    
    

• Calvin Cycle (in stroma):
  
  

  • Fixes CO₂ into glucose using ATP and NADPH
    

Cellular Respiration:

• Location: Mitochondria (aerobic); cytoplasm (anaerobic).
  
  

• Equation:
  C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP(energy)
  
  

• Steps:
  
  

  1. Glycolysis (cytoplasm): Glucose → 2 pyruvate, 2 ATP, 2 NADH
     
     

  2. Krebs Cycle (mitochondrial matrix): CO₂ released, 2 ATP, 6 NADH, 2 FADH₂

3. Electron Transport Chain (ETC) (inner mitochondrial membrane): Oxygen is final electron acceptor → H₂O produced; 32–34 ATP made
   
   

Anaerobic Respiration:

• Occurs in absence of O₂
  
  

• Lactic Acid Fermentation (muscle cells): Glucose → Lactic acid + 2 ATP
  
  

• Alcoholic Fermentation (yeast): Glucose → Ethanol + CO₂ + 2 ATP
  
  

Enzymes:

• Catalysts: Speed up reactions by lowering activation energy.
  
  

• Specificity: Active site binds specific substrate.
  
  

• Affected by: Temperature, pH, inhibitors.
  
  

• Denaturation: Enzyme loses shape and function.
  
  

🧬 CELL STRUCTURE & FUNCTION

Organelles and Their Functions:

• Nucleus: Contains DNA; site of transcription.
  
  

• Ribosomes: Site of protein synthesis (can be free or bound to rough ER).
  
  

• Rough ER: Produces proteins for export or membrane use.
  
  

• Smooth ER: Synthesizes lipids, detoxifies drugs.
  
  

• Golgi Apparatus: Modifies, packages, and ships proteins and lipids.
  
  

• Mitochondria: Site of aerobic respiration (produces ATP).
  
  

• Chloroplasts: Site of photosynthesis in plants.
  
  

• Lysosomes: Contain hydrolytic enzymes; breakdown waste.
  
  

• Vacuoles: Storage (large central vacuole in plants).
  
  

• Cell Membrane: Phospholipid bilayer; selectively permeable.
  
  

Transport Across Membrane:

• Passive Transport (no energy):
  
  

  • Diffusion: Molecules move from high → low concentration.
    
    

  • Osmosis: Water moves across membrane.
    
    

  • Facilitated Diffusion: Uses proteins for transport (e.g., glucose).
    
    

• Active Transport (uses ATP):
  
  

  • Moves against gradient (low → high).
    
    

  • Examples: Sodium-potassium pump, endocytosis, exocytosis.
    
    

🧬 MOLECULAR GENETICS

DNA Structure:

• Double helix (Watson and Crick model).
  
  

• Nucleotides: Sugar (deoxyribose), phosphate, nitrogen base (A-T, C-G).
  
  

• Base pairing: A with T, C with G via hydrogen bonds.
  
  

DNA Replication:

• Semi-conservative: Each new molecule = 1 old + 1 new strand.
  
  

• Enzymes:
  
  

  • Helicase: Unzips DNA
    
    

  • DNA Polymerase: Adds nucleotides
    
    

  • Ligase: Seals fragments
    
    

Protein Synthesis:

• Transcription (in nucleus): DNA → mRNA
  
  

  • RNA Polymerase binds promoter, makes RNA strand.
    
    

• Translation (in cytoplasm/ribosome): mRNA → protein
  
  

  • Codons (3-base mRNA sequences) code for amino acids.
    
    

  • tRNA carries amino acids, anticodon pairs with codon.
    
    

  • Peptide bonds form → polypeptide chain
    
    

Types of RNA:

• mRNA: Messenger RNA (carries code).
  
  

• tRNA: Transfer RNA (brings amino acids).
  
  

• rRNA: Ribosomal RNA (structural part of ribosome).
  
  

Mutations:

• Point Mutation: Single nucleotide change (e.g., sickle cell).
  
  

• Frameshift: Insertion or deletion shifts reading frame.
  
  

• Results: Silent, Missense (wrong aa), Nonsense (stop codon).
  
  

🧬 GENETICS

Mendelian Laws:

• Law of Dominance: Dominant allele masks recessive.
  
  

• Law of Segregation: Alleles separate in gamete formation.
  
  

• Law of Independent Assortment: Genes for different traits segregate independently.
  
  

Punnett Squares:

• Used to predict genotype and phenotype ratios.
  
  

• Monohybrid: 1 trait (Aa x Aa → 1:2:1 geno, 3:1 pheno)
  
  

• Dihybrid: 2 traits (AaBb x AaBb → 9:3:3:1 pheno)
  
  

Complex Patterns:

• Incomplete Dominance: Blend (e.g., red + white = pink).
  
  

• Codominance: Both alleles expressed (e.g., AB blood).
  
  

• Multiple Alleles: More than 2 alleles (e.g., blood types A, B, O).
  
  

• Sex-Linked Traits: Located on X chromosome (e.g., hemophilia, colorblindness).
  
  

🧫 BIOTECHNOLOGY

Key Techniques:

• Gel Electrophoresis:
  
  

  • Separates DNA fragments by size.
    
    

  • DNA moves toward positive electrode.
    
    

• PCR (Polymerase Chain Reaction):
  
  

  • Amplifies DNA using primers and DNA polymerase.
    
    

• Cloning: Copying entire organisms or genes.
  
  

• CRISPR: Gene editing tool using guide RNA and Cas9.
  
  

• Recombinant DNA: Inserting foreign genes into organisms.
  
  

🌱 ECOLOGY

Energy Flow:

• Producers: Autotrophs (photosynthetic organisms).
  
  

• Consumers:
  
  

  • Primary: Herbivores
    
    

  • Secondary: Carnivores
    
    

  • Tertiary: Top predators
    
    

• Decomposers: Break down dead matter (e.g., fungi, bacteria)
  
  

Trophic Levels:

• 10% Rule: Only 10% of energy moves up each level.
  
  

Biogeochemical Cycles:

• Carbon Cycle: CO₂ → photosynthesis → consumers → respiration
  
  

• Nitrogen Cycle: N₂ fixation → nitrification → uptake by plants
  
  

• Water Cycle: Evaporation → condensation → precipitation → runoff
  
  

Symbiosis:

• Mutualism: Both benefit
  
  

• Commensalism: One benefits, one unaffected
  
  

• Parasitism: One benefits, one harmed
  
  

🌍 EVOLUTION

Natural Selection:

• Variation, Overproduction, Competition, Differential survival → Adaptation
  
  

• Individuals with favorable traits reproduce more
  
  

Types of Evolution:

• Convergent: Similar traits in unrelated species
  
  

• Divergent: Differences in closely related species
  
  

• Coevolution: Species evolve in response to one another
  
  

Evidence:

• Fossil Record, Homologous Structures, DNA similarities, Vestigial structures, Embryology

🧪 ENZYMES (Deep Dive)

What They Do:

• Biological catalysts made of proteins.
  
  

• Lower activation energy required for chemical reactions.
  
  

• Speed up the rate of metabolic processes.
  
  

Key Properties:

• Specificity: Each enzyme acts on a specific substrate (like a key to a lock).
  
  

• Reusability: Enzymes aren’t consumed in the reaction.
  
  

• Optimal Conditions:
  
  

  • Temperature: High temps can denature enzymes (change their shape and stop function).
    
    

  • pH: Each enzyme has a specific pH range (e.g., pepsin works in stomach acid; amylase works in neutral saliva).
    
    

  • Substrate Concentration: Reaction rate increases with more substrate until saturation.
    
    

Inhibition:

• Competitive Inhibitor: Blocks active site.
  
  

• Non-competitive Inhibitor: Changes enzyme shape by binding elsewhere.
  
  

Examples:

• Catalase: Breaks down hydrogen peroxide into water + oxygen.
  
  

• Amylase: Breaks down starch in saliva.
  
  

🔁 ENERGY TRANSFER & BIOMOLECULES

Biomolecules:

1. Carbohydrates:
   
   

   • Monomer: Monosaccharide (e.g., glucose)
     
     

   • Function: Quick energy, structural support (cellulose)
     
     

   • Examples: Starch (plants), glycogen (animals)
     
     

2. Proteins:
   
   

   • Monomer: Amino acids
     
     

   • Function: Enzymes, structure (muscles), immune function
     
     

   • Examples: Hemoglobin, keratin, enzymes
     
     

3. Lipids:
   
   

   • Monomer: Glycerol + 3 fatty acids
     
     

   • Function: Long-term energy, insulation, membranes
     
     

   • Types: Saturated (solid), Unsaturated (liquid)
     
     

4. Nucleic Acids:
   
   

   • Monomer: Nucleotides
     
     

   • Function: Store and transmit genetic information
     
     

   • Examples: DNA, RNA
     
     

🧫 MITOSIS VS MEIOSIS

Mitosis:

• Purpose: Growth, repair, asexual reproduction
  
  

• # of divisions: 1
  
  

• End result: 2 diploid (2n) identical cells
  
  

• Phases: PMAT – Prophase, Metaphase, Anaphase, Telophase
  
  

• Cytokinesis: Division of cytoplasm
  
  

• Occurs in: Somatic (body) cells
  
  

Meiosis:

• Purpose: Create gametes (sex cells)
  
  

• # of divisions: 2
  
  

• End result: 4 haploid (n) genetically different cells
  
  

• Crossing over: Occurs in Prophase I (adds genetic variation)
  
  

• Independent Assortment: Random distribution of chromosomes
  
  

• Occurs in: Gonads (testes, ovaries)
  
  

🧬 DNA, RNA, & PROTEINS (Quick Summary Table)

🔬 GENETICS EXTRAS

Pedigrees:

• Circles = females, Squares = males
  
  

• Shaded = affected individuals
  
  

• Horizontal line = mating, vertical line = offspring
  
  

• Patterns show if trait is dominant, recessive, or sex-linked
  
  

Blood Type Inheritance:

• A and B are codominant; O is recessive
  
  

• Genotypes:
  
  

  • Type A: AA or AO
    
    

  • Type B: BB or BO
    
    

  • Type AB: AB
    
    

  • Type O: OO
    
    

🌱 PLANTS & PHOTOSYNTHESIS

Structures:

• Xylem: Transports water upward from roots.
  
  

• Phloem: Transports sugars from leaves.
  
  

• Stomata: Pores for gas exchange (CO₂ in, O₂ out); water can also escape (transpiration).
  
  

• Guard Cells: Open and close stomata.
  
  

Phototropism:

• Plant growth toward light (regulated by hormone auxin).
  
  

Transpiration:

• Water loss from leaves pulls water up through the xylem (cohesion-tension theory).
  
  

🧬 VIRUSES VS CELLS

🧬 IMMUNE SYSTEM

First Line (Nonspecific):

• Skin, mucous membranes, saliva, tears
  
  

Second Line:

• Inflammatory response
  
  

• Phagocytes engulf pathogens
  
  

Third Line (Specific Immunity):

• B cells: Make antibodies (humoral immunity)
  
  

• T cells: Kill infected cells (cell-mediated immunity)
  
  

• Memory cells: Enable quicker response to future exposure
  
  

Vaccines:

• Introduce a weakened or inactive form of the pathogen
  
  

• Stimulates immune memory without causing disease
  
  

🔬 PROPERTIES OF WATER (BIOCHEMISTRY FOUNDATION)

Water is essential for life due to its unique chemical and physical properties:

1. Polarity:

• Water is a polar molecule: Oxygen is slightly negative, hydrogen is slightly positive.
  
  

• Allows hydrogen bonding between molecules.
  
  

2. Cohesion:

• Water molecules stick to each other due to hydrogen bonds.
  
  

• Causes surface tension (e.g., water droplets form beads).
  
  

3. Adhesion:

• Water molecules stick to other substances.
  
  

• Enables capillary action, which helps move water through plant stems.
  
  

4. High Specific Heat:

• Water resists temperature change.
  
  

• Helps organisms maintain stable internal temperatures.
  
  

5. Universal Solvent:

• Water dissolves many polar/charged substances (e.g., salts, sugars).
  
  

• Important for nutrient transport and cellular reactions.
  
  

6. Density of Ice:

• Ice is less dense than liquid water due to hydrogen bond structure.
  
  

• Ice floats, insulating aquatic life in winter.
  
  

⚖ HOMEOSTASIS & FEEDBACK MECHANISMS

Homeostasis = Maintaining a stable internal environment despite external changes.

Negative Feedback:

• Reverses a change to maintain balance.
  
  

• Examples:
  
  

  • Blood glucose regulation by insulin and glucagon
    
    

  • Body temperature regulation (sweating/shivering)
    
    

  • Osmoregulation via ADH (controls water reabsorption in kidneys)
    
    

Positive Feedback:

• Amplifies a response until a goal is achieved.
  
  

• Examples:
  
  

  • Labor contractions (oxytocin)
    
    

  • Blood clotting cascade
    
    

🧫 IMMUNE SYSTEM (ADDITIONAL DETAILS)

Lines of Defense:

1. Barrier Defenses (1st Line):
   
   

   • Skin, mucous membranes, acidic secretions
     
     

2. Innate (2nd Line):
   
   

   • Inflammatory response (histamines, swelling, fever)
     
     

   • Phagocytes: White blood cells engulf invaders
     
     

3. Adaptive (3rd Line):
   
   

   • B cells → antibodies (target antigens in fluids)
     
     

   • T cells:
     
     

     • Helper T cells: Activate B and T cells
       
       

     • Cytotoxic T cells: Destroy infected cells
       
       

Antibodies:

• Proteins that bind to specific antigens
  
  

• Cause clumping or tagging for destruction
  
  

Memory Cells:

• Result from B and T cell activation
  
  

• Provide immunity by responding faster to future infections
  
  

🧬 GENE EXPRESSION & REGULATION

Gene Regulation in Prokaryotes (Operons):

• Operon: Cluster of genes under control of one promoter.
  
  

• Lac operon (inducible):
  
  

  • Normally off; turned on when lactose is present
    
    

• Trp operon (repressible):
  
  

  • Normally on; turned off when tryptophan is abundant
    
    

Gene Regulation in Eukaryotes:

• Transcription Factors: Proteins that bind DNA and influence gene expression
  
  

• Enhancers & Silencers: Non-coding DNA sequences that activate or repress transcription
  
  

• Epigenetics: Changes in gene expression without DNA sequence change (e.g., methylation)
  
  

🧪 EXPERIMENTAL DESIGN (ADVANCED CONSIDERATIONS)

Essential Features of a Good Experiment:

• Testable Hypothesis: Must predict an outcome based on cause-effect.
  
  

• Independent Variable: One factor changed intentionally.
  
  

• Dependent Variable: What is measured (quantitative or qualitative).
  
  

• Constants: Factors kept the same in all groups.
  
  

• Control Group: Used for baseline comparison.
  
  

• Repetition/Replication: Multiple trials and large sample size increase reliability.
  
  

• Data Analysis:
  
  

  • Use of error bars, standard deviation, or statistical tests to determine significance.
    
    

🌍 ECOLOGICAL INTERACTIONS (DETAILED)

Types of Interactions:

• Predation: One organism consumes another.
  
  

• Competition: Two organisms compete for limited resources.
  
  

• Symbiosis:
  
  

  • Mutualism: Both benefit (e.g., bees & flowers)
    
    

  • Commensalism: One benefits, one unaffected (e.g., barnacles on whales)
    
    

  • Parasitism: One benefits, one harmed (e.g., tapeworm in humans)
    
    

Population Dynamics:

• Carrying Capacity (K): Maximum number an environment can support.
  
  

• Logistic Growth: S-curve; growth slows as population nears K.
  
  

• Exponential Growth: J-curve; rapid growth under ideal conditions.
  
  

• Limiting Factors:
  
  

  • Density-dependent: Competition, disease
    
    

  • Density-independent: Natural disasters, climate
    
    

Succession:

• Primary: Begins in lifeless area (volcano/lava); pioneer species like lichens first
  
  

• Secondary: Occurs after disturbance (fire, flood); soil already present