Comprehensive Biology Final Exam Study Guide

Characteristics of Life

Defining Features of Living Organisms

• Order and Structure: Living things exhibit organized structure, from molecules to cells to tissues and organs.

• Reproduction: The ability to produce offspring, either sexually or asexually.

• Growth and Development: Organisms grow and develop according to specific instructions coded in their DNA.

• Energy Processing: Living organisms obtain and use energy to power activities and chemical reactions.

• Adaptation: Populations evolve over generations to become better suited to their environments.

• Regulation: Homeostasis maintains stable internal conditions despite external changes.

The Cell: Prokaryotes vs. Eukaryotes

Cell Types and Their Features

• Prokaryotic Cells: Lack a nucleus, generally smaller, DNA is in the nucleoid region, no membrane-bound organelles. Example: Bacteria.

• Eukaryotic Cells: Have a nucleus, larger, contain membrane-bound organelles (e.g., mitochondria, endoplasmic reticulum).

• Similarities: Both have a plasma membrane, cytoplasm, ribosomes, and DNA.

Plant vs. Animal Cells

• Plant Cells: Rigid cell wall, chloroplasts for photosynthesis, large central vacuole.

• Animal Cells: No cell wall, contain lysosomes, smaller vacuoles.

Major Organelles and Their Functions

• Nucleus: Stores genetic material (DNA), controls cell activities.

• Mitochondria: Site of cellular respiration, produces ATP.

• Chloroplasts: (Plants) Site of photosynthesis.

• Endoplasmic Reticulum (ER): Synthesizes proteins (rough ER) and lipids (smooth ER).

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

• Lysosomes: (Animals) Digestive enzymes for waste breakdown.

• Vacuoles: Storage of water, nutrients, and waste; large in plants.

Cellular Appendages

• Cilia: Short, hair-like; move in a back-and-forth motion (e.g., lining of windpipe).

• Flagella: Long, whip-like; propel cells (e.g., sperm cell tail).

The Chemistry of Life

Atoms and Molecules

• Atoms: Basic units of matter, composed of protons, neutrons, and electrons.

• Chemical Reactions: Atoms form and break bonds to create molecules essential for life.

Metabolic Reactions

• Dehydration Synthesis: Builds macromolecules by removing water.

• Hydrolysis: Breaks down macromolecules by adding water.

Biological Macromolecules

• Carbohydrates: Energy source; monomer = glucose.

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

• Proteins: Structure, enzymes, transport; monomer = amino acids.

• Nucleic Acids: Store genetic information; monomer = nucleotides (DNA, RNA).

Energy and Life

Cellular Respiration

• Purpose: Converts glucose into ATP (energy currency of the cell).

• Aerobic Respiration: Occurs in mitochondria, requires oxygen, produces CO2, water, and ATP.

• Anaerobic Respiration (Fermentation): Begins with glycolysis in cytoplasm, does not require oxygen.

Human Body Systems

Structural Hierarchy

• Organism → Organ System → Organ → Tissue → Cell

• Tissue Types: Epithelial, connective, muscle, nervous.

Digestive System

• Alimentary Canal: Mouth, esophagus, stomach, intestines.

• Accessory Organs: Liver, pancreas, gallbladder.

• Stages of Food Processing: Ingestion, digestion, absorption, elimination.

Circulatory System

• Heart: Pumps blood.

• Arteries/Arterioles: Carry blood away from heart.

• Capillaries: Exchange of gases and nutrients.

• Veins/Venules: Return blood to heart.

Respiratory System

• Main Organs: Lungs, alveoli, diaphragm.

• Function: Gas exchange between body and environment.

Immune System

• Main Components: Lymphocytes (B cells, T cells), white blood cells, lymphatic system.

• Malfunction: Autoimmune diseases (e.g., diabetes type 1).

Endocrine System

• Main Organs: Hypothalamus, pituitary, thyroid, parathyroid, pancreas, adrenal glands, testes, ovaries.

• Hormones: Chemical messengers regulating metabolism, growth, reproduction.

Glucose Regulation and Diabetes

• Regulation: Pancreas releases insulin and glucagon to maintain blood glucose levels.

• Diabetes: Failure of regulation; insufficient insulin (Type 1), insulin resistance (Type 2), gestational (Type 3).

Macromolecules: Fats, Lipids, and Cholesterol

• Fats/Lipids: Energy storage, hormone production, cell structure.

• Cholesterol: Lipid in animal cell membranes; LDL ("bad"), HDL ("good").

• Saturated vs. Unsaturated Fats: Saturated = less healthy; unsaturated = healthier.

Cell Division and Genetics

Cell Division

• Reasons: Reproduction, growth, repair.

• Sexual vs. Asexual Reproduction: Sexual involves gametes; asexual produces identical offspring.

Chromosomes and Cell Cycle

• Structure: DNA and proteins (chromatin), sister chromatids.

• Cell Cycle Phases: Interphase, prophase, metaphase, anaphase, telophase, cytokinesis.

Cancer

• Originates from mutations causing loss of growth regulation.

Genetic Variation

• Mechanisms: Independent assortment, crossing over, random fertilization.

Mitosis vs. Meiosis

• Mitosis: Occurs in somatic cells; produces identical cells.

• Meiosis: Occurs in ovaries/testes; produces gametes with half the chromosome number.

Nondisjunction

• Failure of chromosomes to separate during meiosis, leading to chromosomal abnormalities.

DNA: The Molecule of Life

Nucleus Structure

• Nuclear Envelope: Double membrane with pores.

• Nucleolus: Site of ribosomal RNA synthesis.

• Chromosomes: Store genetic information.

Inheritance Patterns

• Incomplete Dominance: Blending of traits.

• Multiple Alleles: More than two alleles for a gene.

• Pleiotropy: One gene affects multiple traits.

• Polygenic Inheritance: Multiple genes affect one trait.

Sex-Linked Inheritance

• Genes on sex chromosomes; males (XY) more affected by X-linked traits.

Protein Synthesis

• Transcription: DNA → mRNA in nucleus.

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

Genetic Diseases

• Single Gene: Cystic fibrosis.

• Chromosomal: Down syndrome.

• Complex: Type 2 diabetes.

• Mitochondrial: Leber's Hereditary Optic Neuropathy.

Diagnosis and Analysis

• Pedigree analysis, gene therapy, carrier testing.

• DNA sequencing, STR analysis, PCR, gel electrophoresis.

• CODIS: National DNA database for crime solving.

DNA Replication

• Process is semi-conservative: each new DNA has one old and one new strand.

PCR and DNA Profiling

• PCR: Polymerase Chain Reaction; amplifies DNA using a thermal cycler.

• Electrophoresis: Separates DNA fragments by size.

• Short Tandem Repeats (STRs): Used for individual identification.

Evolution and Biodiversity

Natural Selection and Evolution

• Variation, environmental change, survival of the fittest, reproduction, population change.

• Evidence: Fossil records, observable adaptations, disease resistance.

• Artificial Selection: Human-directed breeding (e.g., dog breeding).

Bacterial Genetics and Resistance

• Gene Transfer: Conjugation, transduction.

• Antibiotic Resistance: Evolution of resistant strains via natural selection.

Viruses

• Not considered alive: cannot reproduce independently, no metabolism.

• Structure: Nucleic acid, capsid, recognition spikes.

• Lytic Cycle: Immediate host destruction.

• Lysogenic Cycle: Viral DNA integrates into host genome.

Immune System Defenses

• External Barriers: Skin, mucous membranes, hair, stomach acid.

• Inflammatory Response: Localizes and eliminates pathogens.

• Lymphatic System: Produces lymphocytes for specific immunity.

• Vaccines: Stimulate immune memory without causing disease.

Viral Evolution and Vaccines

• Viruses mutate, affecting immune response and vaccine effectiveness.

• Coronaviruses: Family of viruses; example: SARS-CoV-2 (COVID-19).

• COVID-19 Vaccines: Moderna/Pfizer (mRNA), Johnson & Johnson (viral vector).

Genetic Variation and Inheritance

• Mechanisms: Independent assortment, crossing over, random fertilization.

• Mitosis vs. Meiosis: Mitosis in somatic cells, meiosis in gametes.

• Nondisjunction: Chromosome separation error in meiosis.

Taxonomy and Classification

Taxonomic Hierarchy

• Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species

Domains and Kingdoms

• Domains: Bacteria, Archaea, Eukarya

• Kingdoms of Eukarya: Plantae (e.g., oak tree), Fungi, Animalia

Biodiversity and Ecology

Biodiversity

• Definition: Variety of living things; includes genetic, species, and ecosystem diversity.

• Benefits: Ecosystem services, human health, ecosystem stability.

• Threats: Habitat destruction, invasive species, pollution, climate change.

Ecology

• Definition: Study of interactions between organisms and their environment.

• Levels: Organism, population, community, ecosystem, biosphere.

• Biosphere: All life and environments on Earth.

• Ecosystem Services: Wetlands, coral reefs, raw materials, waste treatment, erosion control.

• Energy Flow: Energy flows one-way; chemicals cycle.

Biomes

• Definition: Ecological community in a climatic zone.

• Examples: Tropical forests, savannas, deserts, chaparrals, grasslands, broadleaf forests, coniferous forests, tundra, polar ice.

Greenhouse Gases and Climate Change

• Sources: Electricity, transportation, industry, residential/commercial use.

• Effect: Increased greenhouse gases raise global temperatures.

Plant Biology

Macronutrients vs. Micronutrients

• Macronutrients: Needed in large amounts (99.5% of plant weight).

• Micronutrients: Needed in small amounts (0.5% of plant weight).

Producers and Consumers

• Producers (plants) and consumers (animals) are linked by photosynthesis and cellular respiration.

Angiosperms

• Monocots: One cotyledon, parallel veins, floral parts in threes (e.g., grasses).

• Dicots: Two cotyledons, net-like veins, floral parts in fours or fives (e.g., roses).

Biogeochemical Cycles

• Carbon Cycle: Sugar production in plants.

• Nitrogen Cycle: Essential for proteins and nucleic acids.

• Water Cycle: Nutrient transport and photosynthesis.

Ecological Footprint

• Measures land and water area needed to sustain a person; relates to resource use in agriculture.

Genetically Modified Organisms (GMOs)

• Increase productivity, improve nutrition, and adaptability in agriculture.

Fungi and Animal Diversity

Fungi

• Characteristics: Decomposers, nutrient cycling, hyphae and mycelium structure.

• Reproduction: Asexual and sexual cycles.

Major Plant Groups

• Bryophytes: Mosses, hornworts.

• Seedless Vascular Plants: Ferns.

• Gymnosperms: Conifers, cone-bearing plants.

• Angiosperms: Flowering plants.

Animal Phylogeny

• Sponges: No tissues or symmetry.

• Cnidarians: Radial symmetry, stinging cells.

• Flatworms: Bilateral symmetry.

• Annelids: Segmented bodies.

• Mollusks: Soft bodies, often with shells.

• Roundworms: Microscopic decomposers.

• Arthropods: Jointed appendages (e.g., crabs).

• Echinoderms: Water vascular system (e.g., starfish).

• Chordates: Nerve cord, tail, notochord, pharyngeal slits; includes vertebrates.

Chordate Features

• Nerve cord, tail, notochord, pharyngeal slits.

Tables

Comparison of Prokaryotic and Eukaryotic Cells

Feature	Prokaryotic	Eukaryotic
Nucleus	No	Yes
Size	Small	Larger
Organelles	None	Membrane-bound
Examples	Bacteria, Archaea	Plants, Animals, Fungi, Protists

Types of Diabetes

Type	Cause	Features
Type 1	Autoimmune destruction of insulin-producing cells	Usually early onset, requires insulin
Type 2	Insulin resistance	Often adult onset, linked to lifestyle
Gestational (Type 3)	Pregnancy-related	Temporary, risk for mother and child

Levels of Taxonomic Classification

Level	Description
Domain	Most broad
Kingdom	Next broadest
Phylum	Major group within kingdom
Class	Group within phylum
Order	Group within class
Family	Group within order
Genus	Group within family
Species	Most specific

Key Equations and Concepts

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

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

• DNA Replication (Semi-conservative): Each new DNA molecule contains one original and one new strand.

• Genetic Variation: $\text{Variation} \xrightarrow{\text{Selection}} \text{Adaptation}$

Summary

This study guide covers the major topics in introductory biology, including the characteristics of life, cell structure, macromolecules, energy processing, human body systems, genetics, evolution, biodiversity, and ecology. It provides definitions, comparisons, examples, and key processes essential for exam preparation.