Comprehensive Study Guide: Foundations of General Biology

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Module 1 – Introduction to Life and Science

What is Biology?

Biology is the scientific study of life and living organisms. It encompasses a wide range of sub-fields, including genetics, ecology, physiology, and molecular biology.

Biology: The study of living organisms and their interactions with the environment.
Sub-fields: Genetics, microbiology, zoology, botany, ecology, physiology, etc.
Importance: Biology impacts medicine, agriculture, environmental science, and daily life.

Characteristics of Living Organisms

All living things share certain characteristics that distinguish them from non-living matter.

Order: Organized structure (cells, tissues, organs).
Regulation: Homeostasis (maintaining internal balance).
Growth and Development: Increase in size and complexity.
Energy Processing: Use of energy for metabolic processes.
Response to Environment: Reacting to stimuli.
Reproduction: Producing offspring.
Evolutionary Adaptation: Populations change over generations.

Levels of Biological Organization

Life is organized in a hierarchy from molecules to the biosphere.

Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Biosphere

Themes in Biology

Evolution: The process by which populations change over time.
Flow of Information: Genetic information is stored in DNA and transmitted across generations.
Structure and Function: Biological structures are adapted to their functions.
Transformation of Matter and Energy: Organisms obtain and use energy and matter.
Interactions Within and Between Systems: Organisms interact with each other and their environment.

Three Domains of Life

Archaea: Prokaryotic, often extremophiles.
Bacteria: Prokaryotic, diverse environments.
Eukarya: Eukaryotic, includes plants, animals, fungi, protists.

Scientific Method in Biology

Observation → Hypothesis → Experiment → Data Collection → Conclusion → Peer Review
Hypothesis: Testable explanation for an observation.
Theory: Broad explanation supported by evidence (different from everyday use of 'theory').

Evolution and Genetics

Charles Darwin: Developed the theory of natural selection.
Natural Selection: Differential survival and reproduction of individuals.
Common Descent with Modification: All organisms share a common ancestor.
Mendel’s Experiments: Led to the concept of the gene and heritability.
Modern Synthesis: Integration of genetics and evolution.
DNA: Encodes genetic information and is the basis for inheritance and evolution.

Module 2 – Chemistry of Life

Atoms, Elements, and Molecules

Atom: Smallest unit of an element.
Element: Pure substance, cannot be broken down further.
Compound: Substance formed from two or more elements in a fixed ratio.
Molecule: Smallest unit of a compound.

Atomic Structure

Protons (positive), Neutrons (neutral), Electrons (negative)
Atomic Number: Number of protons.
Atomic Mass: Protons + Neutrons.
Isotopes: Atoms with same number of protons, different neutrons.

Chemical Bonds

Covalent Bonds: Sharing of electron pairs (can be polar or nonpolar).
Ionic Bonds: Transfer of electrons, resulting in charged ions.
Hydrogen Bonds: Weak bonds between hydrogen and electronegative atoms.

Properties of Water

Moderates temperature, cohesion/adhesion, solvent of life, less dense as a solid.
All due to hydrogen bonding.

Acids, Bases, and pH

Acid: Increases H+ concentration.
Base: Decreases H+ concentration.
pH Scale: Measures H+ concentration (0-14; 7 is neutral).
Buffer: Minimizes changes in pH.

Chemical Reactions

Reactants → Products
Conservation of Matter: Matter is neither created nor destroyed.

Chapter 3 – The Molecules of Cells

Organic Molecules and Biochemistry

Organic Molecules: Contain carbon and hydrogen.
Functional Groups: Methyl, hydroxyl, carboxyl, amino, phosphate.
Monomers and Polymers: Monomers join to form polymers via dehydration synthesis; polymers are broken down by hydrolysis.

Four Major Biomolecule Families

Family	Monomer	Elements	Function
Carbohydrates	Monosaccharide	C, H, O	Energy, structure
Lipids	Glycerol + Fatty Acids	C, H, O (sometimes P)	Energy storage, membranes, hormones
Proteins	Amino Acid	C, H, O, N, (S)	Catalysis, structure, transport
Nucleic Acids	Nucleotide	C, H, O, N, P	Genetic information

Carbohydrates

Monosaccharides (glucose), disaccharides (sucrose), polysaccharides (starch, glycogen, cellulose).

Lipids

Fats (triglycerides), phospholipids (membranes), steroids (cholesterol).
Saturated vs. unsaturated fatty acids.

Proteins

Made of amino acids; structure determines function.
Enzymes are proteins that catalyze reactions.

Nucleic Acids

DNA and RNA; store and transmit genetic information.

Chapter 4 – A Tour of the Cell

Cell Theory and Cell Types

All living things are made of cells; cells are the basic unit of life; all cells come from pre-existing cells.
Prokaryotes (Bacteria, Archaea) vs. Eukaryotes (Eukarya).
Plant vs. animal cells: Plant cells have cell walls, chloroplasts, and large central vacuoles.

Cell Structure and Function

Organelle	Function
Nucleus	Stores genetic material
Ribosome	Protein synthesis
Endoplasmic Reticulum (Smooth/Rough)	Lipid/protein synthesis
Golgi Apparatus	Modifies, sorts, ships proteins
Mitochondrion	ATP production (cellular respiration)
Chloroplast	Photosynthesis (plants/algae)
Plasma Membrane	Selective barrier
Cell Wall	Support (plants, fungi, some protists)

Endosymbiosis: Theory that mitochondria and chloroplasts originated as free-living bacteria.

Chapter 5 – The Working Cell

Membrane Structure and Function

Fluid Mosaic Model: Membrane is a phospholipid bilayer with embedded proteins.
Selective Permeability: Only certain molecules can cross freely.

Transport Mechanisms

Type	Energy Required?	Direction	Example
Simple Diffusion	No	High to low	O2, CO2
Facilitated Diffusion	No	High to low	Glucose via transporter
Active Transport	Yes	Low to high	Na+/K+ pump
Exocytosis	Yes	Out of cell	Secretion of hormones
Endocytosis	Yes	Into cell	Uptake of nutrients

Osmosis and Tonicity

Osmosis: Diffusion of water across a membrane.
Hypotonic: Lower solute outside; water enters cell.
Isotonic: Equal solute; no net water movement.
Hypertonic: Higher solute outside; water leaves cell.

Energy and Enzymes

First Law of Thermodynamics: Energy cannot be created or destroyed.
Second Law of Thermodynamics: Entropy (disorder) increases.
ATP: Main energy currency of the cell.
Enzymes: Biological catalysts; lower activation energy.

Chapter 6 – Harvesting Chemical Energy

Cellular Respiration

Process by which cells extract energy from glucose.
Three main stages: Glycolysis, Krebs Cycle, Oxidative Phosphorylation.
Occurs in mitochondria (eukaryotes).

Summary Equation:

Glycolysis: Glucose → Pyruvate (cytoplasm).
Krebs Cycle: Pyruvate → CO2 (mitochondrial matrix).
Oxidative Phosphorylation: Electron transport chain and chemiosmosis (inner mitochondrial membrane).
ATP Yield: Up to 32 ATP per glucose.
Fermentation: Anaerobic process; less ATP produced.

Chapter 7 – Photosynthesis

Photosynthesis Overview

Process by which photoautotrophs convert light energy to chemical energy.
Occurs in chloroplasts.

Summary Equation:

Light Reactions: Convert light energy to ATP and NADPH (thylakoid membranes).
Calvin Cycle: Uses ATP and NADPH to fix carbon into glucose (stroma).
Pigments: Chlorophyll absorbs light energy.

Chapter 8 – The Cellular Basis of Reproduction and Inheritance

Cell Division

Functions: Growth, repair, reproduction.
Prokaryotic Division: Binary fission.
Eukaryotic Division: Mitosis (somatic cells), Meiosis (gametes).
Cell Cycle: Interphase (G1, S, G2), Mitosis, Cytokinesis.
Chromosome Structure: Chromatin, chromatids, centromere.

Meiosis and Genetic Variation

Reduces chromosome number by half; produces gametes.
Crossing over and independent assortment increase genetic diversity.

Chapter 9 – Patterns of Inheritance

Mendelian Genetics

Gene: Unit of heredity.
Allele: Variant form of a gene.
Genotype: Genetic makeup.
Phenotype: Observable traits.
Dominant/Recessive: Dominant alleles mask recessive ones.
Monohybrid/Dihybrid Crosses: One or two traits.
Law of Segregation: Alleles separate during gamete formation.
Law of Independent Assortment: Genes on different chromosomes assort independently.

Extensions and Applications

Incomplete dominance, codominance, multiple alleles, polygenic inheritance, X-linkage.
Pedigree analysis for human genetics.

Chapter 10 – Molecular Biology of the Gene

DNA Structure and Function

DNA is the hereditary material (Hershey-Chase experiment).
Double helix structure (Watson, Crick, Franklin).
Nucleotides: Sugar, phosphate, nitrogenous base.
Base pairing: A-T, G-C.
Antiparallel strands (5' to 3').

DNA Replication

Semiconservative: Each new DNA has one old and one new strand.
Key enzymes: DNA polymerase, ligase.

Gene Expression

Transcription: DNA → RNA (nucleus in eukaryotes).
Translation: RNA → Protein (ribosome).
Genetic code is universal and redundant.

Mutations

Point mutations, frameshifts, chromosomal mutations.
Can be neutral, harmful, or beneficial.

Chapter 11 – How Genes Are Controlled

Gene Regulation

Prokaryotes: Operons (e.g., lac operon).
Eukaryotes: DNA packing, transcription factors, enhancers/silencers, alternative splicing, microRNA.
Gene expression can be regulated at multiple levels (transcription, translation, protein modification).

Chapter 34 – The Biosphere

Ecology and the Biosphere

Organisms interact with their environment at multiple levels (individual, population, community, ecosystem, biosphere).
Abiotic Factors: Non-living (temperature, water, sunlight).
Biotic Factors: Living (other organisms).
Distribution of life is influenced by both abiotic and biotic factors.

Major Terrestrial Biomes

Biome	Climate	Species Diversity
Tropical Forest	Warm, high rainfall	Very high
Savanna	Warm, seasonal rainfall	Moderate
Desert	Dry, extreme temperatures	Low
Chaparral	Mild, wet winters; hot, dry summers	Moderate
Temperate Grassland	Cold winters, hot summers	Moderate
Temperate Broadleaf Forest	Moderate rainfall, cold winters	High
Coniferous Forest	Cold, moderate rainfall	Moderate
Tundra	Very cold, low precipitation	Low
Polar Ice	Extremely cold, very low precipitation	Very low

Chapter 36 – Population Ecology

Population Growth

Population: Group of individuals of the same species in an area.
Population Density: Number of individuals per unit area.
Dispersion Patterns: Clumped, uniform, random.

Population Growth Models

Exponential Growth: J-shaped curve; unlimited resources.
Logistic Growth: S-shaped curve; limited by carrying capacity (K).

Exponential Growth Equation:

Logistic Growth Equation:

Carrying Capacity (K): Maximum population size environment can support.
Limiting Factors: Density-dependent (competition, disease) and density-independent (weather, disasters).

Human Population

Currently growing, but rate is decreasing (demographic transition).
Age Structure Diagrams: Predict future growth and resource needs.
Ecological Footprint: Measure of resource use per person.

Chapter 37 – Communities and Ecosystems

Interspecific Interactions

Competition: Both species harmed.
Predation: Predator benefits, prey harmed.
Mutualism: Both benefit.
Herbivory: Animal eats plant.
Parasitism: Parasite benefits, host harmed.

Trophic Structure and Energy Flow

Food chains: Producers → Primary consumers → Secondary consumers → Tertiary consumers → Quaternary consumers.
Energy flows; chemical elements cycle.

The Carbon Cycle

Photosynthesis: Plants convert CO2 to organic molecules.
Cellular Respiration: Organisms release CO2 back to atmosphere.
Carbon cycles between atmosphere, organisms, and environment.

Example: Following a Carbon Atom

CO2 in air → Plant (photosynthesis) → Glucose → Animal (eating plant) → Respiration → CO2 released.

Additional info: Where original notes were brief, standard academic context was added for completeness and clarity.