Bio_I_Final_Exam_Review_Units_I-IV_Humphries

UNIT I

CHAPTER 1: Biology

• Theory of Evolution: Explains the unity and diversity of life.

  • Darwin's concept of artificial selection parallels natural selection.

  • Populations tend to grow faster than food supplies, leading to a struggle for survival.

  • Variations occur among offspring; favorable traits enhance survival and are passed on (survival of the fittest).

• Biological Domains BAE:

  • Bacteria & Archaea: Unicellular prokaryotes, lack membrane-bound organelles, including a nucleus. Archaea are extremophiles, sharing traits with eukaryotes.

  • Eukaryotes: Can be unicellular or multicellular, possess membrane-bounded organelles.

• Biological Scale: BECPOOsOTMA

  • Biosphere, Ecosystem, Community (interacting populations), Population, Organism, Organ system, Organ, Tissue, Molecule, Atom.

• Scientific Methods:

  • Reductionism vs. Systems Biology: Breaking components down into simpler parts vs. understanding how all parts work together.

  • Observation (discovery) vs. Hypothesis-based science.

    • Hypothesis: Educated guess; tentative explanation.

    • Theory: Supported by extensive evidence, explains diverse observations.

  • Typical Steps: OQHEAC

    • Initial Observation, Question, Hypothesis, Experiment, Analyze results, Conclusion.

CHAPTER 2: Chemistry

• Atomic Mass/Atomic Number:

  • Atomic mass = protons + neutrons (varies in isotopes, e.g., 12C vs. 14C).

  • Atomic number = number of protons, determines the element.

• Key Elements for Life: Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N) - CHON.

• Periodic Table: Elements arranged in vertical columns (groups) and rows (periods) indicate similar properties and electron shell structure.

• Trace Elements: Essential in small quantities.

  • Example: Goiter due to iodine deficiency.

• Bonding:

  • Ionic Bonding: Attraction between charged ions; cations (positive) donate electrons, anions (negative) gain electrons, forming lattice crystals.

  • Covalent Bonding: Co-sharing of valence electrons to form molecules. Can be nonpolar (equal sharing) or polar (unequal sharing, leading to slight charges).

    • Hydrogen Bonds: Interactions between H (connected to O or N) of one molecule and O or N of another.

• Electronegativity: Affects ionic and covalent bonding; F is the most electronegative element.

• Van Der Waals Forces: Weak attraction due to temporary changes in electron distribution.

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CHAPTER 3: Water

• Emergent Properties of Water: Based on hydrogen bonding in polar covalent molecules.

  • Cohesion: Attraction between like molecules due to hydrogen bonding; contributes to surface tension.

  • Adhesion: Attraction to unlike substances; water droplets on leaves represent this property.

  • Temperature Moderation: Large bodies of water heat/cool slowly; high specific heat capacity due to hydrogen bonds.

  • Insulation: Ice is less dense than water, insulating objects in colder temperatures.

  • Solvent: Polar water can form hydration shells around ions.

    • Hydrophilic: Water-loving (polar/ionic); Hydrophobic: Water-fearing (non-polar).

• pH Scale: Ranges from 1 (acidic) to 14 (basic); relates to H+ concentration.

  • Water naturally dissociates into H+ (H3O+) and OH-. [H+] x [OH-] = 10^-14.

  • Buffers: Stabilize pH, e.g., carbonic acid and bicarbonate.

CHAPTER 4: Carbon

• Bonding Capacity: Carbon can bond with four different atoms, resulting in diverse organic molecules.

• Isomers: Structural isomers have the same molecular formula but different shapes.

  • Cis-trans isomers: Differ in arrangements around double bonds.

• Functional Groups: Chemically reactive groups in organic compounds that dictate properties.

  • Examples: Hydroxyl (-OH), Carbonyl (>C=O), Carboxylic acid (-COOH), Amino (-NH2), Phosphate (-PO4), Methyl (-CH3).

CHAPTER 5: Biological Molecules

• Types of Macromolecules:

  • Carbohydrates: Sugars and starches (mono-, di-, poly-).

  • Lipids: Fats, oils, steroids, phospholipids.

  • Proteins: Composed of amino acids (20 types).

  • Nucleic Acids: DNA and RNA (nucleotide monomers).

• Starch vs. Cellulose: Starch stores energy with helical glucose chains, while cellulose provides strength through linear chains; humans digest starch but not cellulose.

• Dehydration Synthesis & Hydrolysis: Removal of water links monomers into polymers; addition splits polymers into monomers.

• Triglycerides: Composed of glycerol and three fatty acids; encompass saturated and unsaturated fats.

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CHAPTER 6: The Cell

• Prokaryotic vs. Eukaryotic Cells: Prokaryotes lack membrane-bound organelles; eukaryotes have nucleus and organelles.

• Functions of Organelles:

  • Nucleus: Genetic information storage.

  • Smooth ER: Lipid synthesis and detoxification.

  • Rough ER: Protein synthesis.

  • Golgi Apparatus: Modifies and ships proteins.

  • Mitochondria: Energy production via cellular respiration.

  • Cytoskeleton: Provides structure and movement.

  • Lysosomes: Contain digestive enzymes.

• Cell Theory:

  • All organisms are made of at least one cell.

  • Cells are the basic unit of life.

  • All cells arise from preexisting cells.

• Organelle Differences in Plants and Animals:

  • Plant cells possess chloroplasts and a central vacuole.

• Membrane Structure and Function:

  • Plasma Membrane: Phospholipids and proteins create a fluid mosaic model.

  • Transport Mechanisms:

    • Passive Transport: No energy required; substances move down the concentration gradient.

    • Active Transport: Energy (ATP) required to move substances against their gradient.

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CHAPTER 8 & 9: Metabolism and Cellular Respiration

• Energy Transfer: Energy cannot be created or destroyed (First Law of Thermodynamics).

• Metabolism: Set of chemical reactions to maintain life; includes:

  • Exergonic Reactions: Release energy (e.g., cellular respiration).

  • Endergonic Reactions: Require energy (e.g., photosynthesis).

• ATP: Energy currency of the cell.

  • Produced during cellular respiration:

    • Glycolysis: Glucose to pyruvate, net gain of 2 ATP.

    • Citric Acid Cycle: Further processes pyruvate; produces ATP and electron carriers (NADH and FADH2).

    • Oxidative Phosphorylation: ATP synthesized using electron transport chain and chemiosmosis.

    • Osmosis Effects: Solute concentration affects water transport across membranes.

CHAPTER 10: Photosynthesis

• Photosynthesis Process:

  • Converts light energy into chemical energy (glucose).

  • Light-dependent reactions produce ATP and NADPH, which power the Calvin cycle.

  • Overall Reaction: 6H2O + 6CO2 + light → C6H12O6 + 6O2.

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UNIT III

CHAPTER 16: DNA Replication

• Components of DNA Replication: helicase, primase, DNA polymerase, ligase.

  • Synthesized in 5’-3’ direction with an anti-parallel structure.

  • Continuous and lagging strands formed due to Okazaki fragments.

CHAPTER 12: Cell Cycle & Mitosis

• Cell Cycle Phases: G1, S (DNA replication), G2, Mitotic phase (prophase, metaphase, anaphase, telophase), followed by cytokinesis.

CHAPTER 13: Meiosis

• Meiosis: Reduction division creating gametes with half the chromosome set; two phases (Meiosis I and II).

CHAPTER 14: Mendel Genetics

• Genetic Principles:

  • Punnett Squares: Used to predict offspring genotype ratios.

  • Laws: Segregation & Independent Assortment.

  • Phenotypic Ratios: 3:1 (monohybrid), 9:3:3:1 (dihybrid).

  • Inheritance Patterns: Co-dominance, multiple alleles, polygenic inheritance.

CHAPTER 15: Chromosomal Basis of Inheritance

• Traits: Sex-linked traits (color-blindness) and linked genes.

• Chromosomal Changes: Non-disjunction, insertions, inversions; genetic imprinting examples.

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CHAPTER 17: From Gene to Protein

• Genetic Information Flow: From DNA to RNA to protein; key processes are Transcription and Translation.

• Transcription: DNA to mRNA via RNA polymerase; involves splicing of introns/exons.

• Translation: Ribosomes translate mRNA codons into polypeptides, using tRNA.

ALTERNATE GENE SPLICING

• Different exon combinations can produce various proteins from the same gene.

CHAPTER 18: Gene Expression

• Prokaryotes: Use operons to control gene expression.

• Eukaryotes: Complex regulation includes transcription factors, chromatin modifications, and signaling proteins.

• Gene Expression Control: Enhancers and repressors modulate expression levels based on signals.

CHAPTER 19: Viruses

• Viruses: Obligate intracellular parasites requiring a host to replicate.

• Structural Components: Genetic material (DNA or RNA) and a protective capsid; some possess envelopes.

• Reproductive Cycles: Lytic (active) and lysogenic (integration into host genome).

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CHAPTER 20: Biotechnology

• Biotechnology: Manipulating organisms to create products; includes genetic engineering techniques (e.g., DNA cloning).

• Applications: PCR, sequencing, reproductive cloning, and therapeutic uses of stem cells.

CHAPTER 21: Genomes and Their Evolution

• Genomics: Study of entire gene sets; compares genomes to understand evolution.

  • Techniques: Shotgun sequencing, microarrays, bioinformatics.

  • Eukaryotic Gene Complexity: Includes alternative splicing producing diverse proteins.

  • Chromosomal Structuring: Changes contribute to evolutionary processes; the analysis of pseudogenes can reveal common ancestry.