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 variable (manipulated), and dependent variable (responding).

• 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 Properties of Water

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

• Adhesion: Attraction between water and other substances (e.g., water climbing plant vessels).

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

• Capillary Action: Movement of water within narrow spaces, important for transpiration in plants.

• Transpiration: Water movement from roots to leaves, driven by 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 and structure (e.g., cellulose in plants).

  • Lipids: Long-term energy storage, cell membranes (e.g., fats, phospholipids).

  • Proteins: Structure, enzymes, transport (e.g., keratin in hair).

  • Nucleic Acids: Store genetic information (DNA, RNA).

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

• Monomers and Polymers: Monomers are building blocks (e.g., amino acids for proteins); polymers are chains of monomers.

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

• Hydrolysis vs. Dehydration Synthesis: Hydrolysis breaks polymers (adds water); dehydration synthesis forms polymers (removes water).

• 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 and Functions: Nucleus (DNA storage), mitochondria (energy), chloroplasts (photosynthesis), ER (protein/lipid synthesis), Golgi (modification/transport), lysosomes (digestion), etc.

• Coordination: Organelles work together (e.g., nucleus codes for proteins, ribosomes synthesize, Golgi modifies/ships).

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.

• Concentration Gradient: Difference in concentration; drives diffusion rate.

• 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, osmosis); active (requires energy, e.g., sodium-potassium pump).

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

5.12–5.13 ATP and Enzymes

• ATP: Main energy currency of the cell.

• Enzymes: Biological catalysts; lower activation energy, increase reaction rate, specific to substrates, not consumed in reactions.

• Environmental Effects: Temperature and pH affect enzyme activity; extreme conditions cause denaturation (loss of structure/function).

Chapter 6: How Cells Harvest Chemical Energy

6.1–6.8, 6.11 Cellular Respiration

• Stages: Glycolysis (cytoplasm, anaerobic), Krebs Cycle (mitochondria, aerobic), Electron Transport Chain (mitochondria, aerobic).

• Reactants/Products: Glucose and oxygen produce CO2, water, and ATP.

• Final Electron Acceptor: Oxygen in aerobic respiration.

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

• Key Equations: $\text{Cellular Respiration:} \\ \mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP}$ $\text{Photosynthesis:} \\ \mathrm{6CO_2 + 6H_2O + light \ energy \rightarrow C_6H_{12}O_6 + 6O_2}$

• Chemiosmosis: Process by which ATP is produced using a proton gradient and ATP synthase.

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.

• Final Electron Acceptor (Light Reactions): NADP+ forms NADPH.

• Chloroplasts vs. Mitochondria: Recognize structure and function in diagrams.

Chapter 8: The Cellular Basis of Reproduction and Inheritance

8.1, 8.3–8.10 Cell Division and 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 (prophase, metaphase, anaphase, telophase), Cytokinesis.

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

8.12–8.20 Meiosis

• Function: Produces gametes with half the chromosome number; increases genetic variation.

• Genetic Variation: Crossing over, independent assortment.

• Key Terms: Haploid, diploid, homologous pairs, crossing over, zygote, autosomes, sex chromosomes.

• Karyotype: Visual representation of chromosomes; used to detect abnormalities (e.g., nondisjunction).

Chapter 9: Patterns of Inheritance

9.2–9.5 Mendelian Genetics

• Mendel: Father of genetics; studied pea plants.

• Key Terms: Heredity, trait, gene, homozygous, heterozygous, dominant, recessive, Law of Segregation.

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

• Punnett Squares: Used to predict genotype and phenotype ratios.

• Monohybrid vs. Dihybrid Cross: One trait vs. two traits.

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

9.8 Pedigrees and Sex-Linked Traits

• Pedigree Analysis: Traces inheritance patterns; autosomal dominant/recessive, sex-linked traits.

• Sex-Linked Inheritance: Traits on X or Y chromosome; often 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 forms of a gene (e.g., blood types).

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

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

9.20–9.21 Sex-Linked Traits

• Punnett Squares: Used for sex-linked inheritance problems.

Chapter 10: Molecular Biology of the Gene

10.2–10.3 DNA and RNA

• DNA vs. RNA: DNA is double-stranded, deoxyribose sugar; RNA is single-stranded, ribose sugar.

• Genetic Code: Sequence of DNA bases determines traits.

• Nucleotide Structure: Phosphate, sugar, nitrogenous 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; occurs in nucleus.

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

10.6–10.13 Protein Synthesis

• Central Dogma: DNA → RNA → Protein.

• Transcription: DNA to mRNA in nucleus.

• Translation: mRNA to protein at ribosome; tRNA brings amino acids.

• Codons/Anticodons: Codons (mRNA, 3 bases); anticodons (tRNA).

• Mutations: Changes in DNA sequence; can alter protein function.

10.16 Locations and Functions

• 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 evolutionary relationships.

Chapter 13: How Populations Evolve

13.1–13.5 Adaptation and Evidence

• Adaptations: Traits that improve survival/reproduction.

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

13.6–13.8 Natural Selection

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

• Genetic Variation: Mutation, gene shuffling.

• Key Terms: Mutation, gene pool, fitness, allele frequency.

13.9–13.11 Hardy-Weinberg Principle

• Conditions: Large population, random mating, no mutation, no migration, no selection.

• Equation: $p^2 + 2pq + q^2 = 1$ $p + q = 1$ Where p and q are 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 shared by a group, used in cladistics.

• Kingdom Characteristics: Cell type, nutrition, multicellularity.

• Cladograms/Phylogenetic Trees: Show evolutionary relationships.

• Determining Common Ancestry: Morphology, molecular data, biotechnology.

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

Chapter 20: Animal Structure and Function

• Feedback Loops: Negative feedback maintains homeostasis; positive feedback amplifies change.

Chapter 21: Nutrition and Digestion

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

• Chemical vs. Mechanical Digestion: Mechanical (chewing, stomach churning); chemical (enzymes, begins 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 → bronchioles → alveoli.

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

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

Chapter 23: Circulation

• Blood Flow Pathway: Body → right atrium → right ventricle → lungs → left atrium → left ventricle → body.

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

• Blood Pressure: Normal ~120/80 mmHg; high/low readings indicate 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 signal across synapse.

• Brain Regions: Cerebrum (thinking), cerebellum (coordination), midbrain, hindbrain.

Chapters 31–33: Plants

Chapter 31: Plant Structure

• Key Characteristics: Multicellular, autotrophic, cell walls of cellulose.

• Structures: Roots (absorption), shoots (support), root hairs (increase surface area).

• Tissues: Vascular (xylem, phloem), dermal (guard cells, stomata).

• Cuticle: Waxy layer prevents water loss.

• Leaf/Flower Structure: Know parts and functions.

Chapter 32: Plant Nutrition and 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 tip of plant senses light (phototropism).

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 and matter cannot be created or destroyed.

Chapter 37: Communities and Ecosystems

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

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

• Biomass: Total mass of living matter; represented in pyramids.

• Food Chains/Webs: Show energy flow; only ~10% of energy transferred to next level (10% Rule).

• 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 stability.

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

Transport Type	Energy Required?	Example
Passive (Diffusion, Osmosis, Facilitated Diffusion)	No	O2 entering cell, glucose via protein channel
Active Transport	Yes (ATP)	Sodium-potassium pump

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

Additional info: This guide covers foundational concepts in introductory biology, including cell structure, genetics, evolution, physiology, plant biology, and ecology. For deeper understanding, refer to textbook figures and diagrams as indicated in the original study guide.