Final (Ch. 1-14)

Chapter 1: Introduction to Biology

Biology and Society: A Passion for Life

Biology is the scientific study of life, driven by human curiosity about the natural world. Understanding biology is essential for human and societal well-being, as it informs decisions about health, environment, and society.

• Curiosity about Life: Humans have an inherent interest in living things and the environment.

• Relevance: Biological knowledge helps us make informed decisions about health, conservation, and society.

The Scientific Study of Life

Science uses a systematic approach to understanding the natural world through inquiry, observation, and evidence-based conclusions.

• Scientific Inquiry: Involves searching for information, evidence, and answers to specific questions.

• Natural Causes: Science focuses on phenomena that can be observed and measured.

Exploration in Science

• Data: Recorded observations that serve as evidence for scientific inquiry.

• Hypothesis: A testable and falsifiable proposed explanation for a set of observations.

• Theory: A comprehensive, well-substantiated explanation supported by extensive evidence.

Controlled Experiments

• Variables: Factors that change in an experiment.

• Independent Variable: Manipulated by researchers as a potential cause.

• Dependent Variable: The response or effect measured in the experiment.

Blind and Double-Blind Studies

Type of Study	Test Subjects Know Which Group Is Which?	Researchers Know Which Group Is Which?
Not Blind	Yes	Yes
Single Blind	No	Yes
Double Blind	No	No

Evaluating Scientific Claims

• Pseudoscience: Falsely presented as scientific, often based on anecdotal evidence and lacking repeatability or peer review.

• Science: Adheres to established methods, produces repeatable results, and is open to scientific review.

Features of Science	Features of Pseudoscience
Adheres to scientific method	Does not adhere to accepted processes
Repeatable results	Results cannot be duplicated
Testable claims	Unprovable or unreliable claims
Open to outside review	Rejection of external review
Multiple lines of evidence	Observation as anecdotal evidence

The Properties of Life

Living organisms display a set of properties that distinguish them from nonliving objects.

• Order

• Cells

• Growth and Development

• Energy Processing

• Regulation

• Response to Environment

• Reproduction

• Evolution

Property	Description
Order	Highly organized structure
Cells	Basic unit of life
Growth and Development	Increase in size and change over time
Energy Processing	Use of energy to power activities
Regulation	Maintaining internal stability
Response to Environment	Reacting to stimuli
Reproduction	Producing new organisms
Evolution	Change over generations

Chapter 2: Essential Chemistry for Biology

Elements and Compounds

All biological systems are composed of matter, which is made up of elements and compounds.

• Element: A pure substance that cannot be broken down by chemical means.

• Compound: A substance consisting of two or more elements in a fixed ratio.

Abbreviated Periodic Table of the Elements

• Atomic number: Number of protons in an atom.

• Atomic mass: Mass of the average atom of that element.

Chemical Composition of the Human Body

Element	Body Percentage
Oxygen (O)	65.0%
Carbon (C)	18.5%
Hydrogen (H)	9.5%
Nitrogen (N)	3.3%
Calcium (Ca)	1.5%
Phosphorus (P)	1.0%
Others (trace)	<0.01%

Atoms and Chemical Bonds

• Atom: Smallest unit of matter retaining element properties.

• Subatomic particles: Protons (positive), Neutrons (neutral), Electrons (negative).

• Chemical bonds: Atoms interact by transferring or sharing electrons.

Types of Chemical Bonds

• Ionic bonds: Formed between oppositely charged ions.

• Covalent bonds: Atoms share one or more pairs of electrons.

• Hydrogen bonds: Weak electrical attractions between water molecules.

Water and Life

• Cohesion: Tendency of molecules to stick together, stronger in water due to hydrogen bonds.

• Temperature moderation: Water resists temperature changes due to hydrogen bonding.

• Solvent of Life: Water dissolves many substances, facilitating chemical reactions.

Acids, Bases, and pH

• Acid: Releases H+ ions into solution.

• Base: Accepts H+ ions and removes them from solution.

• pH scale: Measures hydrogen ion concentration; lower pH is more acidic, higher pH is more basic.

• Buffer: Minimizes changes in pH.

Substance	pH Value
Battery acid	1
Lemon juice	2
Human blood	7.4
Household bleach	13

Key Equations

• Mass number: $\text{Mass number} = \text{Number of Protons} + \text{Number of Neutrons}$

• Half-life calculation: $N_t = N_0 \times (1/2)^{t/t_{1/2}}$

Chapter 3: The Molecules of Life

Organic Compounds

• Organic compounds: Molecules primarily composed of carbon atoms bonded with hydrogen, oxygen, and nitrogen.

• Carbon's versatility: Forms four covalent bonds, allowing for a wide variety of molecular structures.

Macromolecules and Polymers

• Macromolecules: Large molecules essential for life, including carbohydrates, proteins, lipids, and nucleic acids.

• Polymers: Assembled by linking smaller units called monomers.

Synthesis and Breakdown of Polymers

• Dehydration reaction: Links two monomers, removing a water molecule.

• Hydrolysis: Breaks polymers by adding water.

Equation: $\text{Monomer} + \text{Monomer} \rightarrow \text{Dehydration} (\text{Polymer} + H_2O)$

Large Biological Molecules

• Carbohydrates

• Lipids

• Proteins

• Nucleic acids

Carbohydrates

• Monosaccharides: Simple sugars (e.g., glucose, fructose).

• Polysaccharides: Long chains of monosaccharides (e.g., starch, glycogen, cellulose).

Polysaccharide	Function	Location
Starch	Energy storage	Plants
Glycogen	Energy storage	Animals
Cellulose	Structural support	Plants

Lipids

• Hydrophobic: Water-fearing; lipids are hydrophobic.

• Fats: Composed of glycerol and three fatty acids.

• Saturated fats: Animal fats, solid at room temperature.

• Unsaturated fats: Plant/fish oils, liquid at room temperature.

• Trans fats: Processed foods, unhealthy type of unsaturated fat.

Type of Fat	Source	Physical State
Saturated	Animal fats	Solid
Unsaturated	Plant/fish oils	Liquid
Trans	Processed foods	Solid

Proteins

• Polymers of amino acid monomers.

• Essential for many cellular functions.

Protein Type	Function	Example
Structural	Support	Collagen
Storage	Amino acid storage	Egg albumin
Contractile	Movement	Actin, myosin
Transport	Transport substances	Hemoglobin
Enzyme	Catalysis	Amylase

Nucleic Acids

• Macromolecules that store genetic information and provide instructions for building proteins.

• Two types: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

Feature	DNA	RNA
Sugar	Deoxyribose	Ribose
Bases	A, T, G, C	A, U, G, C
Strands	Double	Single

Equation: $\text{Nucleotide} + \text{Nucleotide} \rightarrow \text{Dehydration} (\text{Polynucleotide} + H_2O)$

Chapter 4: A Tour of the Cell

Cell Theory and Cell Diversity

• All living organisms are composed of cells, which are the basic units of life.

• Cells are classified as prokaryotic (bacteria, archaea) or eukaryotic (plants, animals, fungi, protists).

Prokaryotic Cells	Eukaryotic Cells
First evolved 3.5 billion years ago	First evolved 2.1 billion years ago
Bacteria and archaea	Plants, fungi, animals
Smaller, simpler	Larger, more complex

Cell Structure: Prokaryotic and Eukaryotic Cells

• Prokaryotic: Plasma membrane, cell wall, capsule, nucleoid, ribosomes, flagella.

• Eukaryotic: Plasma membrane, nucleus, organelles (ER, Golgi apparatus, mitochondria, etc.).

Membrane Structure

• Plasma membrane: Regulates the flow of materials into and out of the cell.

• Fluid mosaic model: Describes the membrane as a mosaic of proteins and phospholipids.

Cell Surfaces

• Cell wall: Provides protection and structural support (plants, fungi, bacteria).

• Extracellular matrix: Animal cells have a matrix for support and cell signaling.

The Nucleus and Ribosomes

• Nucleus: Contains most of the cell's DNA.

• Ribosomes: Sites of protein synthesis.

The Endomembrane System

• Endoplasmic reticulum (ER): Synthesis and transport of proteins and lipids.

• Golgi apparatus: Modifies, sorts, and ships cellular products.

• Lysosomes: Digestive enzymes for breakdown of macromolecules.

• Vacuoles: Storage and transport in plant and animal cells.

Chapter 5: The Working Cell

Energy and Cellular Work

• Energy: The capacity to cause change; exists in kinetic and potential forms.

• ATP (adenosine triphosphate): The primary energy carrier in cells.

Equation: $\text{ATP} \rightarrow \text{ADP} + P_i + \text{energy}$

Enzymes and Metabolism

• Enzymes: Biological catalysts that speed up chemical reactions.

• Activation energy: The initial energy needed to start a chemical reaction.

• Enzyme inhibitors: Molecules that inhibit enzyme activity.

Membrane Structure and Function

• Transport across membranes: Includes passive (diffusion, osmosis) and active transport.

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

Active Transport and Bulk Transport

• Active transport: Requires energy to move molecules against their concentration gradient.

• Endocytosis/Exocytosis: Bulk movement of materials into/out of the cell.

Chapter 6: Cellular Respiration

Obtaining Energy from Food

• Cellular respiration: The process by which living organisms extract energy from food molecules.

• Aerobic capacity: The maximum rate at which oxygen can be taken in and used by muscle cells.

Energy Flow and Chemical Cycling

• Producers: Organisms that produce organic matter from inorganic ingredients (e.g., plants).

• Consumers: Organisms that consume producers (e.g., animals).

Process	Inputs	Outputs
Photosynthesis	CO2, H2O, sunlight	Glucose, O2
Cellular Respiration	Glucose, O2	CO2, H2O, ATP

Stages of Cellular Respiration

• Glycolysis: Occurs in the cytoplasm; splits glucose into pyruvic acid.

• Citric Acid Cycle: Completes breakdown of glucose; produces CO2, NADH, FADH2, ATP.

• Electron Transport: Transfers electrons to generate ATP.

Overall equation: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + 36-38 \text{ATP}$

Stage	Main Inputs	Main Outputs	ATP Yield
Glycolysis	Glucose, 2 ATP, 2 NAD+	Pyruvic acid, 2 ATP, 2 NADH	2
Citric Acid Cycle	Acetyl CoA, NAD+, FAD	CO2, NADH, FADH2, ATP	2
Electron Transport	NADH, FADH2, O2	CO2, H2O, ATP	~28

Chapter 7: Photosynthesis

Using Light to Make Food

• Photosynthesis: The process by which plants, algae, and some bacteria convert solar energy into chemical energy.

• Autotrophs: Organisms that produce their own organic matter from inorganic ingredients.

Equation: $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$

Chloroplasts: Sites of Photosynthesis

• Chloroplasts: Organelles in plant cells where photosynthesis occurs.

• Thylakoid: Location of light reactions.

• Stroma: Location of Calvin cycle.

The Light Reactions

• Light reactions: Convert solar energy to chemical energy (ATP and NADPH).

• Calvin cycle: Uses ATP and NADPH to convert CO2 into glucose.

Component	Function
Chlorophyll	Site of photosynthesis
Thylakoid	Location of light reactions
Stroma	Location of Calvin cycle
ATP & NADPH	Energy carriers for Calvin cycle
G3P	Product of Calvin cycle; precursor to glucose

Chapter 8: Cellular Reproduction & Meiosis

Introduction to Cellular Reproduction

• Cell division: The process by which a parent cell divides into two daughter cells.

• Asexual reproduction: Offspring are genetically identical to the parent.

• Sexual reproduction: Offspring inherit a unique combination of genes from two parents.

The Cell Cycle and Mitosis

• Interphase: Cell growth, normal functions, and duplication of DNA.

• Mitosis: Division of the nucleus, producing two genetically identical daughter cells.

Meiosis: The Basis of Sexual Reproduction

• Meiosis: Reduces chromosome number by half, producing gametes for sexual reproduction.

• Genetic variation: Results from independent assortment and crossing over during meiosis.

Mitosis	Meiosis
One division	Two divisions
Produces 2 diploid cells	Produces 4 haploid cells
Daughter cells genetically identical	Daughter cells genetically unique
Growth, repair, asexual reproduction	Sexual reproduction (gametes)

Chapter 9: Patterns of Heredity

Genetics and Heredity

• Genetics: The scientific study of heredity.

• Heredity: Transmission of traits from parents to offspring.

Mendel's Experiments

• Hybrid: Offspring of two different parental varieties.

• Cross: Cross-fertilization between different varieties.

Mendel's Laws

• Law of Segregation: Each organism inherits two alleles for each gene, which segregate during gamete formation.

• Law of Independent Assortment: Inheritance of one character does not affect inheritance of another.

Human Traits Controlled by a Single Gene

Disorder	Major Symptoms
Albinism	Lack of pigment in skin, hair, and eyes
Cystic fibrosis	Mucus in lungs, increased infection risk
Phenylketonuria (PKU)	Accumulation of phenylalanine, intellectual disability
Sickle-cell disease	Misshapen red blood cells, tissue damage
Achondroplasia	Dwarfism
Alzheimer's disease (some types)	Mental deterioration
Huntington's disease	Uncontrollable movements, cognitive impairment
Hypercholesterolemia	Excess cholesterol, heart disease

Probability in Genetics: $P(A \, \text{and} \, B) = P(A) \times P(B)$

Punnett Square Ratio: Monohybrid cross: 1:2:1 genotypic ratio; 3:1 phenotypic ratio

Chapter 10: The Structure and Function of DNA

DNA and RNA Structure

• DNA: Double helix composed of nucleotides (deoxyribose sugar, phosphate group, nitrogenous base).

• RNA: Single strand, ribose sugar, uracil instead of thymine.

Component	DNA	RNA
Sugar	Deoxyribose	Ribose
Bases	A, T, G, C	A, U, G, C
Structure	Double helix	Single strand

DNA Replication

• Template mechanism: Each strand serves as a template for a new complementary strand.

• Base pairing: A pairs with T; G pairs with C.

From DNA to RNA to Protein

• Transcription: DNA information is transcribed into RNA.

• Translation: RNA information is used to build polypeptides (proteins).

DNA Codon	RNA Codon	Amino Acid
ATG	AUG	Methionine (Start)
TAA	UAA	Stop
GGC	GGC	Glycine

Chapter 11: How Genes Are Controlled

Biology and Society: Breast Cancer and Chemotherapy

Breast cancer is a major health concern, with early detection and treatment significantly improving survival rates. Genetic analysis allows for personalized approaches to treatment.

• Early Treatment: Nearly 100% five-year survival rate if detected early.

• Advanced Cancer: Less than 25% five-year survival rate if cancer has spread.

• Targeted Medicine: Surgery, chemotherapy, and radiation are standard options.

• Genetic Testing: Can reveal gene mutations, enabling more effective therapies.

How and Why Genes are Regulated

Gene regulation is the process by which cells control gene expression, allowing cells to differentiate and respond to environmental changes.

• Gene Regulation Mechanisms: Control which specific genes are on or off, allowing cells to specialize.

• Gene Expression: The process by which genetic information flows from genes to proteins.

• Examples: Bacteria regulate genes in response to environmental stimuli; multicellular organisms use gene regulation for development and differentiation.

Gene Regulation in Bacteria

Bacteria primarily regulate gene expression by controlling transcription, often using operons.

• Operon Model: Groups related functions as grouped and regulated together.

• Repressor Proteins: Can block RNA polymerase, preventing transcription of genes.

• Inducers: Molecules that can remove repressors, allowing gene expression.

• Diagram: The lac operon shows how the presence or absence of lactose controls gene expression in bacteria.

Gene Regulation in Eukaryotic Cells

Eukaryotic gene regulation is more complex, with multiple control points from DNA to protein.

• DNA Packing: Chromatin structure can inactivate genes (e.g., X chromosome inactivation in female mammals).

• Transcriptional Regulation: Transcription factors bind enhancers and promoters to regulate gene expression.

• RNA Processing: Addition of a cap and tail, removal of introns, and splicing of exons.

• Alternative RNA Splicing: Different mRNAs can be produced from the same gene.

• microRNAs and RNA Interference: Small RNAs bind to complementary mRNA sequences, blocking translation or causing degradation.

The Initiation of Translation and Protein Activation/Breakdown

Gene expression can be regulated at the level of translation and post-translational modifications.

• Translation Control: Regulatory molecules can affect whether mRNA is translated.

• Protein Activation: Some proteins require chemical modifications to become active.

• Protein Breakdown: Selective degradation of proteins affects cellular protein levels.

Cell Signaling

Cells communicate through chemical signals that regulate gene expression in target cells.

• Signal Transduction Pathway: A series of molecular changes triggered by a signal.

• Example: Hormones can regulate gene expression in distant cells.

Homeotic Genes

Homeotic genes are master control genes that regulate the development of body structures during embryogenesis.

• Function: Control the expression of groups of genes, determining the location and pattern of body parts.

• Example: Mutations in homeotic genes can cause dramatic changes in organismal structure.

Chapter 12: DNA Technology

Introduction: Are More Genes Better?

Humans have about the same number of genes as a microscopic worm, highlighting that gene number alone does not directly correlate with organismal complexity.

• Human Genome: ~21,000 genes; fruit flies ~40,000 genes; microscopic worms ~20,000 genes.

• Gene Regulation: Complexity arises from gene regulation and interactions, not just gene number.

Biology and Society: Using DNA to Establish Guilt and Innocence

DNA profiling is used in forensics to identify individuals and establish guilt or innocence.

• Polymerase Chain Reaction (PCR): Amplifies specific DNA segments for analysis.

• Short Tandem Repeat (STR) Analysis: Compares highly repeated DNA sequences at specific sites.

• Gel Electrophoresis: Separates DNA fragments by size for comparison.

Technique	Main Purpose
PCR	Amplify DNA segments
STR Analysis	Compare repeat lengths at specific loci
Gel Electrophoresis	Sort DNA fragments by size

Genetic Engineering and Biotechnology

Biotechnology involves the manipulation of organisms or their components to make useful products.

• Genetically Modified Organisms (GMOs): Organisms that have acquired one or more genes by artificial means.

• Transgenic Organisms: Host organisms that contain genes from another species.

Recombinant DNA Techniques

Recombinant DNA is created by combining DNA from two different sources, often different species, to form a single DNA molecule.

• Gene Cloning: Production of multiple copies of a gene for practical purposes.

• Applications: Includes production of chemicals, e.g., insulin, drugs, genetically engineered crops, and gene therapy.

Gene Editing: The CRISPR-Cas9 System

CRISPR-Cas9 allows precise editing of specific genes in living cells.

• Purpose: Can reveal gene function or correct mutations.

• Applications: Gene knockouts, mutation corrections (e.g., Duchenne muscular dystrophy).

Medical Applications of DNA Technology

• Production of Useful Proteins: Genes for useful proteins are inserted into bacteria, yeast, or other cells to produce large quantities of proteins (e.g., insulin).

• Gene Therapy: Treats disease by introducing genes into affected individuals.

• Replacement: Mutant gene replaced or supplemented with normal allele.

• Suppression: Genes inserted for short-term treatment.

Safety, Ethical, and Societal Issues

• Risks: Creation of hazardous organisms, transfer of harmful genes.

• Regulation: Strict laboratory procedures and government guidelines.

• Controversy: Issues include food safety, environmental impact, and labeling of GMOs.

• Ethical Questions: Privacy, consent, and genetic discrimination.

Chapter 13: How Populations Evolve

Introduction: The Cheetah and Genetic Diversity

Endangered species, such as the cheetah, face extinction risk due to a lack of genetic diversity. Genetic diversity is essential for populations to adapt to changing environments.

• Genetic Diversity: The variety of alleles within a population. Low diversity can make populations vulnerable to disease and environmental changes.

The Diversity of Life: Taxonomy and Classification

Taxonomy is the science of identifying, naming, and classifying species. The Linnaean system organizes species into a hierarchy.

Rank	Example
Species	Panthera pardus
Genus	Panthera
Family	Felidae
Order	Carnivora
Class	Mammalia
Phylum	Chordata
Kingdom	Animalia
Domain	Eukarya

Explaining the Diversity of Life: Evolutionary Theory

Charles Darwin's theory of evolution explains the origin of species and the diversity of life through natural selection.

• Evolution: Descent with modification; species change over time.

• Natural Selection: Mechanism by which individuals with advantageous traits survive and reproduce.

Evidence for Evolution

• Fossil Record: Ordered sequence of fossils in rock layers, showing changes over time.

• Homology: Similarity due to common ancestry, seen in anatomical structures and DNA sequences.

• Vestigial Structures: Remnants of features that served important functions in ancestors.

• Comparative Embryology: Similar developmental stages in vertebrate embryos indicate common ancestry.

Structure	Species
Forelimb	Human, Cat, Whale, Bat

Key Points About Natural Selection

• Struggle for Existence: Only some offspring survive to reproduce.

• Adaptive Traits: Traits that improve survival and reproduction are passed on.

• Pesticide Resistance: Not caused by pesticides, but by selection for pre-existing resistant individuals.

• Antibiotic Resistance: Overuse of antibiotics selects for resistant bacteria (e.g., MRSA).

Sources of Genetic Variation

• Mutation: Change in DNA sequence; can be beneficial, neutral, or harmful.

• Sexual Reproduction: Shuffles alleles, increasing genetic diversity through independent assortment, crossing over, and fertilization.

Population Genetics: Gene Pool and Hardy-Weinberg Equilibrium

The gene pool represents all alleles in a population. Hardy-Weinberg equilibrium describes a non-evolving population.

• Equation:

• Application: Used to calculate carrier frequencies for genetic diseases (e.g., PKU).

Mechanisms of Evolution

• Natural Selection: Differential survival and reproduction.

• Genetic Drift: Random changes in allele frequencies, especially in small populations.

• Gene Flow: Movement of alleles between populations via migration.

Natural Selection: Outcomes and Fitness

• Fitness: Measured by an individual's reproductive success relative to others in the population.

• Types of Natural Selection: Directional, disruptive, and stabilizing selection.

Chapter 14: How Biological Diversity Evolves

Biology and Society: Humanity's Footprint

Human activities have profoundly impacted Earth's ecology and geology, leaving a lasting mark known as the Anthropocene epoch.

• Human Footprint: Includes global transport of species, widespread agriculture, environmental pollution, and climate change.

The Origin of Species

Speciation is the evolutionary process by which new biological species arise, contributing to the diversity of life.

• Species: Defined by the ability to interbreed and produce fertile offspring.

• Reproductive Barriers: Prevent closely related species from interbreeding.

Barrier Type	Example
Behavioral Isolation	Different courtship rituals
Habitat Isolation	Species occupy different habitats
Temporal Isolation	Species breed at different times
Reduced Hybrid Fertility	Horse × Donkey = Sterile mule

Mechanisms of Speciation

• Allopatric Speciation: Geographic barriers isolate populations, leading to reproductive isolation and divergence.

• Sympatric Speciation: Occurs without geographic isolation, often due to polyploidy in plants.

Polyploid Speciation Type	Description
Autopolyploidy	Chromosome doubling in a single species (2n → 4n)
Allopolyploidy	Hybridization between two species, followed by chromosome doubling

Earth History and Macroevolution

Macroevolution encompasses evolutionary changes above the species level, including mass extinctions and the origin of major adaptations.

• Geologic Time Scale: Earth's history spans periods based on fossil record.

• Plate Tectonics: Movement of Earth's crust shapes the distribution of organisms.

Earth Layer	Description
Crust	Thin, solid outer layer
Mantle	Hot, viscous material beneath crust
Outer Core	Liquid metal
Inner Core	Solid metal