bio EOC review

This is a comprehensive overview of a standard high school or introductory college biology course. Because of the sheer volume of information, I have synthesized the answers into clear, organized sections for each unit to help you study effectively.

UNIT 1: Scientific Inquiry & Ecology

Scientific Method & Measurement

  • Variables:

    • Independent Variable (IV): The factor you change (the "cause"). It goes on the X-axis. Ex: Amount of fertilizer given to a plant.

    • Dependent Variable (DV): The factor you measure (the "effect"). It goes on the Y-axis. Ex: Height of the plant.

  • Groups:

    • Experimental Group: Receives the independent variable.

    • Control Group: Does not receive the IV; used as a baseline for comparison. It is critical to ensure that results are actually caused by the variable being tested.

  • Data Types: Qualitative is descriptive (color, smell); Quantitative is numerical (5cm, 10 grams).

  • Scientific Method Steps: 1. Observation, 2. Hypothesis, 3. Experiment, 4. Data Collection, 5. Analysis, 6. Conclusion.

  • Theory vs. Law: A Theory explains why something happens (Cell Theory); a Law describes what happens consistently under certain conditions (Law of Gravity).

Microscopy

  • Total Magnification: Eyepiece (usually 10x) multiplied by Objective lens.

    • Low (4x) = 40x

    • Medium (10x) = 100x

    • High (45x) = 450x

  • Microscope Movement: Due to the lenses, if you move a slide left, it appears to move right through the eyepiece.

  • Light vs. Electron: Light microscopes use light and lenses (can view living things); Electron microscopes use electron beams (much higher magnification, but specimens must be dead).

Ecology & Behavior

  • Organization: Organism $\rightarrow$ Population $\rightarrow$ Community $\rightarrow$ Ecosystem $\rightarrow$ Biome $\rightarrow$ Biosphere.

  • Energy Transfer: Energy flows in one direction (Sun $\rightarrow$ Producer $\rightarrow$ Consumer). Only 10% of energy is passed to the next level; the rest is lost as heat.

  • Relationships:

    • Mutualism: Both benefit (+/+).

    • Commensalism: One benefits, one unaffected (+/0).

    • Parasitism: One benefits, one harmed (+/-).

  • Behaviors: Innate (instincts like suckling or hibernation) vs. Learned (imprinting, classical conditioning like Pavlov’s dogs).

UNIT 2: Molecular Biology

  • Bonds: Ionic involves transferring electrons; Covalent involves sharing electrons.

  • Water Properties: Water is Polar (unequal charge). Adhesion is water sticking to other things; Cohesion is water sticking to itself.

  • The 4 Biomolecules:

    1. Carbohydrates: Energy (Subunit: Monosaccharides).

    2. Lipids: Long-term energy/membranes (Subunit: Fatty acids/Glycerol).

    3. Proteins: Structure/Enzymes (Subunit: Amino Acids).

    4. Nucleic Acids: Genetic info (Subunit: Nucleotides).

  • Enzymes: These are protein catalysts that speed up reactions by lowering activation energy. They work like a Lock and Key; if they get too hot or the pH changes, they denature (lose shape and stop working).

Image of enzyme lock and key model

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UNIT 3: Cells & Cellular Processes

  • Cell Types:

    • Prokaryotes: No nucleus, no membrane-bound organelles (Bacteria).

    • Eukaryotes: Have a nucleus and organelles (Plants, Animals, Fungi).

  • Organelles:

    • Mitochondria: Powerhouse (Cellular Respiration/ATP).

    • Chloroplast: Photosynthesis (Plants only).

    • Ribosomes: Protein synthesis.

    • Plasma Membrane: Maintains homeostasis by controlling what enters/leaves.

  • Transport:

    • Passive: No energy (Diffusion, Osmosis - high to low concentration).

    • Active: Requires ATP (Low to high concentration).

  • Photosynthesis: $6CO_2 + 6H_2O + light \rightarrow C_6H_{12}O_6 + 6O_2$.

  • Respiration: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$.

UNIT 4: Reproduction & DNA

  • DNA Structure: Double helix made of nucleotides (A pairs with T, C pairs with G).

  • DNA vs. RNA: DNA is double-stranded with Deoxyribose and Thymine; RNA is single-stranded with Ribose and Uracil.

  • Protein Synthesis:

    1. Transcription: DNA $\rightarrow$ mRNA (in the nucleus).

    2. Translation: mRNA $\rightarrow$ Protein (at the ribosome).

  • Cell Division:

    • Mitosis: Creates 2 identical diploid (2n) daughter cells for growth/repair.

    • Meiosis: Creates 4 unique haploid (n) gametes (sperm/egg) for sexual reproduction.

UNIT 5: Genetics & Biotechnology

  • Mendelian Genetics:

    • Genotype: Genetic makeup (e.g., $Tt$).

    • Phenotype: Physical appearance (e.g., Tall).

    • Homozygous: Two of the same allele ($TT$ or $tt$).

    • Heterozygous: Two different alleles ($Tt$).

  • Blood Types: Type A ($I^AI^A, I^Ai$), B ($I^BI^B, I^Bi$), AB ($I^AI^B$), and O ($ii$).

  • Biotechnology:

    • Gel Electrophoresis: Separates DNA fragments by size to create a DNA Fingerprint.

    • Transgenic Organisms: Organisms containing DNA from another species.

UNIT 6: Evolution

  • Natural Selection: "Survival of the Fittest." Organisms with favorable traits survive and reproduce.

  • Evidence for Evolution:

    • Homologous Structures: Similar bone structures in different species (common ancestor).

    • Vestigial Structures: Leftover parts with no current use (e.g., whale pelvic bone).

  • Speciation: Formation of new species, often caused by Geographic Isolation (rivers, mountains).

  • Classification: Domain $\rightarrow$ Kingdom $\rightarrow$ Phylum $\rightarrow$ Class $\rightarrow$ Order $\rightarrow$ Family $\rightarrow$ Genus $\rightarrow$ Species.