Comprehensive Biology Honors Final Exam Study Guide

Chapter 1: Biology – The Study of Scientific Life

1.1 What is Life?

• Characteristics of Life: All living things share certain properties, including organization, metabolism, homeostasis, growth, reproduction, response to stimuli, and adaptation. Example: Plants grow toward light (response to stimulus).

• Homeostasis: The maintenance of a stable internal environment. Example: Human body temperature regulation.

• Unicellular vs. Multicellular: Unicellular organisms consist of one cell (e.g., Amoeba), while multicellular organisms have many cells (e.g., humans).

• Autotrophs vs. Heterotrophs: Autotrophs produce their own food (e.g., plants via photosynthesis); heterotrophs consume other organisms (e.g., animals).

1.4–1.5 The Process of Science

• Scientific Method: Involves observation, hypothesis formation, experimentation, and analysis.

• Hypothesis: A testable statement; can be null (no effect) or alternative (effect expected).

• Experimental Design: Includes control group, independent (manipulated) variable, and dependent (responding) variable.

• Claim, Evidence, Reasoning (CER): Framework for scientific explanation.

• Data Interpretation: Ability to read graphs and analyze results is essential.

Chapter 2: The Chemical Basis of Life

2.8–2.14 Water Properties

• Cohesion: Attraction between water molecules (surface tension).

• Adhesion: Attraction between water and other substances (capillary action).

• Surface Tension: Water's surface resists external force due to cohesion.

• Capillary Action: Movement of water up narrow tubes, important in plant transpiration.

• Transpiration: Water movement through plants, relying on cohesion, adhesion, and capillary action.

Chapter 3: The Molecules of Cells

3.1, 3.3–3.8, 3.12–3.14 Biomolecules

• Organic vs. Inorganic Compounds: Organic compounds contain carbon and hydrogen (e.g., glucose); inorganic do not (e.g., water).

• Major Biomolecules:

  • Carbohydrates: Energy source; monomer = monosaccharide (e.g., glucose).

  • Lipids: Energy storage, membranes; monomer = fatty acids/glycerol.

  • Proteins: Structure, enzymes; monomer = amino acid.

  • Nucleic Acids: Genetic information; monomer = nucleotide.

• Elements in Biomolecules: CHONPS (Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur).

• Protein Folding: Structure determines function; denaturation disrupts function.

• Monomer vs. Polymer: Monomers are building blocks; polymers are chains of monomers.

• Hydrolysis & Dehydration Synthesis: Hydrolysis breaks polymers; dehydration synthesis forms them.

• Energy Storage: Chemical bonds in organic molecules store energy.

Chapter 4: A Tour of the Cell & Chapter 5: The Working Cell

4.2–4.18 Cell Structure

• Cell Walls: Found in plants, fungi, bacteria; not in animal cells.

• Cell Membranes: Present in all cells; regulate entry/exit of substances.

• Eukaryotes vs. Prokaryotes: Eukaryotes have nucleus and organelles (e.g., plants, animals); prokaryotes lack nucleus (e.g., bacteria).

• Organelles: Structures with specialized functions (e.g., mitochondria, chloroplasts, nucleus).

• Cell Cooperation: Organelles work together (e.g., nucleus codes for proteins, ribosomes synthesize them, ER and Golgi process and transport).

5.1 Plasma Membrane

• Components: Phospholipid bilayer, proteins, cholesterol, carbohydrates.

• Membrane Proteins: Transport, signaling, cell recognition.

5.3–5.9 Membrane Transport

• Diffusion: Movement from high to low concentration.

• Osmosis: Diffusion of water across a selectively permeable membrane.

• Selectively Permeable: Allows some substances to pass, not others.

• Concentration Gradient: Difference in concentration; drives diffusion.

• Solution Types:

  • Hypertonic: Higher solute outside; cell loses water.

  • Hypotonic: Lower solute outside; cell gains water.

  • Isotonic: Equal solute; no net water movement.

• Active vs. Passive Transport: Passive (no energy, e.g., diffusion); active (requires energy, e.g., sodium-potassium pump).

• Facilitated Diffusion: Passive transport via proteins (e.g., glucose transport).

5.12–5.13 ATP & Enzymes

• ATP: Main energy currency of the cell.

• Enzymes: Biological catalysts; lower activation energy, increase reaction rate.

• Active Site & Substrate: Enzyme binds substrate at active site; specificity due to shape.

• Denaturation: Loss of structure (due to temperature, pH) leads to loss of function.

Chapter 6: How Cells Harvest Chemical Energy

6.1–6.8, 6.11 Cellular Respiration

• Stages: Glycolysis, Krebs Cycle, Electron Transport Chain (ETC)/Chemiosmosis.

• Aerobic vs. Anaerobic: Glycolysis is anaerobic; Krebs and ETC are aerobic.

• ATP Yield: Aerobic respiration produces more ATP than anaerobic.

• Formulas:

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

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

Chapter 7: Photosynthesis

7.2–7.5 Photosynthesis Overview

• Energy Source: Sunlight is the ultimate energy source.

• Light Reactions: Occur in thylakoid membranes; produce ATP and NADPH.

• Calvin Cycle (Light-Independent): Occurs in stroma; uses ATP/NADPH to fix CO2 into glucose.

• Chloroplasts: Site of photosynthesis; mitochondria for respiration.

Chapter 8: The Cellular Basis of Reproduction and Inheritance

8.1, 8.3–8.10 Cell Division & Mitosis

• Cell Division: Process by which cells reproduce.

• Parent/Daughter Cells: Parent cell divides to form genetically identical daughter cells (mitosis).

• Asexual vs. Sexual Reproduction: Asexual (one parent, identical offspring); sexual (two parents, genetic variation).

• Somatic Cells vs. Gametes: Somatic = body cells (diploid); gametes = sex cells (haploid).

• Cell Cycle: Interphase (G1, S, G2), Mitosis, Cytokinesis.

• Mitosis: Prophase, Metaphase, Anaphase, Telophase; results in two identical cells.

• Chromosome Number: Humans: 46 in somatic, 23 in gametes.

8.12–8.20 Meiosis

• Meiosis: Produces gametes; reduces chromosome number by half.

• Genetic Variation: Crossing over, independent assortment.

• Haploid/Diploid: Haploid (n), diploid (2n).

• Autosomes vs. Sex Chromosomes: Autosomes = non-sex chromosomes; sex chromosomes determine gender.

• Karyotype: Chromosome chart; can show nondisjunction (abnormal number).

Chapter 9: Patterns of Inheritance

9.2–9.5 Mendelian Genetics

• Mendel: Father of genetics; studied pea plants.

• Trait, Gene, Allele: Trait = characteristic; gene = DNA segment; allele = gene variant.

• Homozygous vs. Heterozygous: Homozygous = same alleles; heterozygous = different alleles.

• Law of Segregation: Alleles separate during gamete formation.

• Dominant/Recessive: Dominant masks recessive.

• P, F1, F2 Generations: Parental, first filial, second filial.

• Punnett Squares: Predict offspring genotypes/phenotypes.

• Genotype/Phenotype: Genotype = genetic makeup; phenotype = physical trait.

• Common Ratios: Monohybrid (3:1), dihybrid (9:3:3:1).

9.8 Pedigrees & Sex-Linked Traits

• Pedigree Analysis: Track inheritance patterns (autosomal dominant/recessive, sex-linked).

• Sex-Linked Traits: Often X-linked; more common in males.

9.11–9.14 Non-Mendelian Genetics

• Incomplete Dominance: Heterozygote shows intermediate phenotype.

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

• Multiple Alleles: More than two alleles (e.g., blood types).

• Blood Types: A, B, AB, O; Rh factor.

• Karyotype & Nondisjunction: Chromosome number abnormalities (e.g., Down syndrome).

Chapter 10: Molecular Biology of the Gene

10.2–10.3 DNA & RNA Structure

• DNA vs. RNA: DNA = double helix, deoxyribose, thymine; RNA = single strand, ribose, uracil.

• Genetic Code: DNA sequence determines traits.

• Nucleotide Structure: Phosphate, sugar, base.

• Bonds: Covalent bonds in backbone; hydrogen bonds between bases.

• Base Pairing: DNA: A–T, C–G; RNA: A–U, C–G (Chargaff’s rule).

10.4–10.5 DNA Replication

• Purpose: Copy DNA before cell division.

• Leading vs. Lagging Strand: Continuous vs. discontinuous synthesis.

10.6–10.13 Protein Synthesis

• Central Dogma: DNA → RNA → Protein.

• Transcription: DNA to mRNA (nucleus).

• Translation: mRNA to protein (ribosome).

• Codons/Anticodons: Codon = mRNA triplet; anticodon = tRNA triplet.

• Mutations: Changes in DNA; can alter protein.

10.16 Locations & Organelles

• Replication: Nucleus.

• Transcription: Nucleus.

• Translation: Cytoplasm/ribosome.

• Three Bases (Codon): Code for one amino acid.

Chapter 12: DNA Technology and Genomics

• Restriction Enzymes: Cut DNA at specific sequences.

• Gel Electrophoresis: Separates DNA fragments by size; used to compare species (evolutionary relationships).

Chapter 13: How Populations Evolve

13.1–13.5 Adaptation & Evidence

• Adaptation: Trait that increases fitness.

• Evidence of Evolution: Fossils, homologous/vestigial structures, biochemistry.

13.6–13.8 Natural Selection

• Evolution: Change in allele frequencies over time.

• Darwin’s Theory: Natural selection drives evolution; requires variation, inheritance, differential survival/reproduction.

• Genetic Variation: Mutation, gene shuffling.

• Gene Pool: All alleles in a population.

13.9–13.11 Hardy-Weinberg Principle

• Equilibrium Conditions: No mutation, random mating, no gene flow, infinite population, no selection.

• Equation: $p^2 + 2pq + q^2 = 1$ (genotype frequencies); $p + q = 1$ (allele frequencies).

13.12–13.14 Types of Selection

• Directional: Favors one extreme.

• Stabilizing: Favors intermediate.

• Disruptive: Favors both extremes.

Chapter 15: Tracing Evolutionary History

• Derived Characters: Traits unique to a group.

• Kingdom Characteristics: Cell type, nutrition, multicellularity.

• Cladograms/Phylogenetic Trees: Show evolutionary relationships.

• Common Ancestry: Determined by morphology, DNA, proteins.

Chapters 20–23, 28–29: Animals & Body Systems

Chapter 20: Animal Structure & Function

• Feedback Loops: Negative (stabilizes), positive (amplifies change).

Chapter 21: Nutrition & Digestion

• Alimentary Canal: Mouth → esophagus → stomach → small intestine → large intestine → anus.

• Chemical vs. Mechanical Digestion: Mechanical (chewing, stomach churning); chemical (enzymes, starts in mouth for carbs).

• Digestive Enzymes: Amylase (carbs), protease (proteins), lipase (fats).

• Peristalsis: Muscle contractions move food.

Chapter 22: Gas Exchange

• Respiratory Pathway: Nose → pharynx → larynx → trachea → bronchi → lungs.

• Negative Pressure Breathing: Diaphragm contracts, air drawn in.

• Feedback: CO2 levels regulate breathing via nervous/circulatory systems.

Chapter 23: Circulation

• Blood Flow: Pulmonary (heart–lungs–heart), systemic (heart–body–heart).

• Arteries vs. Veins: Arteries carry blood away from heart; veins toward heart.

• Blood Pressure: Normal ~120/80 mmHg; high/low indicates health issues.

• Blood Components: Red cells (O2), white cells (immunity), platelets (clotting), plasma (fluid).

Chapter 28: Nervous Systems

• Neuron Structure: Dendrite, cell body, axon, synapse.

• Impulse Pathway: Dendrite → cell body → axon → synapse.

• Action Potential: Electrical signal; neurotransmitters transmit across synapse.

• Brain Regions: Cerebrum (thinking), cerebellum (movement), midbrain/hindbrain (basic functions).

Chapters 31–33: Plants

Chapter 31: Plant Structure & Function

• Plant Kingdom: Multicellular, autotrophic, cell walls (cellulose).

• Roots, Shoots, Root Hairs: Absorb water/nutrients, support, increase surface area.

• Tissues: Vascular (xylem: water; phloem: food), dermal (protection, guard cells, stomata).

• Cuticle: Waxy layer prevents water loss.

• Leaf & Flower Structure: Adapted for photosynthesis and reproduction.

Chapter 32: Plant Nutrition & Transport

• Transpiration: Water loss via leaves; driven by cohesion, adhesion, capillary action.

• Stomata: Open/close to regulate gas exchange; water pressure controls opening.

Chapter 33: Control Systems in Plants

• Plant Hormones: Auxin controls phototropism (growth toward light).

• Tropisms: Phototropism (light), gravitropism (gravity), thigmotropism (touch).

• Darwin’s Experiment: Showed tips of shoots sense light.

Chapters 34 & 37: Ecology

Chapter 34: The Biosphere

• Ecology: Study of interactions among organisms and their environment.

• Biotic/Abiotic Factors: Living/nonliving components.

• Levels of Organization: Population, community, ecosystem, biosphere.

• Ultimate Energy Source: Sunlight.

• Law of Conservation: Energy/matter cannot be created or destroyed.

Chapter 37: Communities & Ecosystems

• Symbiotic Relationships: Mutualism (+/+), predation (+/–), parasitism (+/–), herbivory (+/–), commensalism (+/0).

• Trophic Levels: Producers, consumers (primary, secondary, etc.), decomposers.

• Biomass: Total mass of living matter at each trophic level.

• Food Chains/Webs: Show energy flow; 10% rule (only 10% energy passed to next level).

• Limiting Factors: Density-dependent (e.g., disease), density-independent (e.g., weather).

• Carrying Capacity: Maximum population an environment can support.

• Predator-Prey Cycles: Populations fluctuate in response to each other.

• Competition: Intraspecific (within species), interspecific (between species).

• Keystone Species: Disproportionate effect on ecosystem.

• Trophic Cascades: Changes at one level affect others (e.g., Yellowstone wolves).

Table: Comparison of Cell Types

Feature	Prokaryotic Cell	Eukaryotic Cell
Nucleus	No	Yes
Organelles	No membrane-bound	Yes
Examples	Bacteria, Archaea	Plants, Animals, Fungi, Protists
Size	Small (1–10 μm)	Larger (10–100 μm)

Table: Types of Selection

Type	Description	Example
Directional	Favors one extreme phenotype	Antibiotic resistance in bacteria
Stabilizing	Favors intermediate phenotype	Human birth weight
Disruptive	Favors both extremes	Beak size in finches

Table: Blood Types and Genotypes

Blood Type	Genotype(s)
A	IAIA or IAi
B	IBIB or IBi
AB	IAIB
O	ii

Additional info: This guide synthesizes key concepts from each major biology topic, providing definitions, examples, and essential tables for exam preparation. For deeper understanding, refer to textbook figures and diagrams as indicated in the original study guide.