General Biology Final Exam Study Guide: Key Concepts and Topics

Scientific Inquiry and Experimental Design

Independent and Dependent Variables

Understanding variables is essential for designing and interpreting experiments in biology.

• Independent Variable: The factor that is changed or manipulated in an experiment.

• Dependent Variable: The factor that is measured or observed in response to changes in the independent variable.

• Example: Testing the effect of light intensity (independent) on plant growth (dependent).

Core Themes in Biology

Major Unifying Concepts

Biology is unified by several core themes, including evolution, structure and function, energy flow, and information transfer.

• Evolution: The process by which populations change over time through natural selection.

• Structure and Function: Biological structures are adapted to their functions.

• Energy Flow: Organisms require energy to maintain life processes.

• Information Transfer: Genetic information is passed from one generation to the next.

Chemical Context of Life

Atomic Structure and Chemical Bonds

Atoms are the basic units of matter, composed of subatomic particles.

• Subatomic Particles: Protons (positive), neutrons (neutral), electrons (negative).

• Types of Chemical Bonds: Covalent (sharing electrons), ionic (transfer of electrons), hydrogen bonds (weak attractions between polar molecules).

• Example: Water molecules are held together by hydrogen bonds.

Water and Life

Properties of Water

Water is vital for life due to its unique chemical and physical properties.

• Cohesion and Adhesion: Water molecules stick to each other and to other surfaces.

• High Specific Heat: Water resists changes in temperature.

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

Carbon and Biological Molecules

Macromolecules: Structure and Function

Large biological molecules are essential for cellular structure and function.

• Carbohydrates: Energy storage and structural support.

• Lipids: Membrane structure and energy storage.

• Proteins: Enzymes, structural components, signaling.

• Nucleic Acids: Genetic information storage and transfer.

Enzymes and Metabolism

Enzyme Function and Regulation

Enzymes are biological catalysts that speed up chemical reactions.

• Hydrolysis and Dehydration Synthesis: Hydrolysis breaks polymers into monomers; dehydration synthesis joins monomers to form polymers.

• Enzyme Specificity: Enzymes are specific to their substrates due to their active site structure.

• Factors Affecting Enzyme Activity: Temperature, pH, substrate concentration.

Cell Structure and Function

Prokaryotic vs. Eukaryotic Cells

Cells are the basic units of life, with two major types: prokaryotic and eukaryotic.

• Prokaryotic Cells: Lack a nucleus and membrane-bound organelles (e.g., bacteria).

• Eukaryotic Cells: Have a nucleus and organelles (e.g., plants, animals).

• Cell Membrane: Controls movement of substances in and out of the cell.

Membrane Structure and Transport

Transport Mechanisms

Cells regulate the movement of molecules across membranes.

• Passive Transport: Diffusion and osmosis; no energy required.

• Active Transport: Requires energy (ATP) to move substances against their concentration gradient.

• Facilitated Diffusion: Uses transport proteins to move molecules across membranes.

Cellular Respiration and Photosynthesis

Energy Conversion in Cells

Cells convert energy through metabolic pathways.

• Cellular Respiration: Converts glucose to ATP; includes glycolysis, Krebs cycle, and electron transport chain.

• Photosynthesis: Converts light energy to chemical energy in plants; includes light-dependent and light-independent reactions.

• Fermentation: Anaerobic process that produces ATP without oxygen.

Cell Cycle and Division

Mitosis and Meiosis

Cells reproduce through division, ensuring genetic continuity and diversity.

• Mitosis: Produces two identical daughter cells for growth and repair.

• Meiosis: Produces four genetically unique gametes for sexual reproduction.

• Phases: Prophase, metaphase, anaphase, telophase.

Genetics and Inheritance

Mendelian Genetics and Problem Solving

Genetics explains how traits are inherited from one generation to the next.

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

• Dominant and Recessive Alleles: Dominant alleles mask recessive ones in heterozygotes.

• Monohybrid and Dihybrid Crosses: Single and double trait inheritance.

• Non-Mendelian Inheritance: Includes codominance, incomplete dominance, multiple alleles.

Inheritance Pattern	Description	Example
Mendelian	Dominant/recessive alleles	Pea plant flower color
Codominance	Both alleles expressed	AB blood type
Incomplete Dominance	Intermediate phenotype	Pink snapdragons
Multiple Alleles	More than two alleles	Blood type (A, B, O)

DNA Structure and Function

Replication, Transcription, and Translation

Genetic information is stored, copied, and expressed through molecular processes.

• DNA Replication: Semi-conservative process; each new DNA molecule has one old and one new strand.

• Transcription: DNA is used to synthesize RNA.

• Translation: RNA directs protein synthesis at ribosomes.

• Central Dogma: $\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$

Evolution and Natural Selection

Mechanisms of Evolution

Populations evolve through genetic changes over time.

• Natural Selection: Differential survival and reproduction of individuals with advantageous traits.

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

• Gene Flow: Movement of alleles between populations.

• Mutation: Source of genetic variation.

Classification and Diversity of Life

Major Groups of Organisms

Life is classified into domains and kingdoms based on shared characteristics.

• Domains: Bacteria, Archaea, Eukarya.

• Kingdoms: Protists, Fungi, Plants, Animals.

• Animal Phyla: Examples include Chordata, Arthropoda, Mollusca, Nematoda.

Domain	Key Features	Example
Bacteria	Prokaryotic, unicellular	Escherichia coli
Archaea	Prokaryotic, extremophiles	Halobacterium
Eukarya	Eukaryotic, multicellular or unicellular	Plants, animals, fungi

Ecology and Environmental Biology

Population and Community Ecology

Ecology studies interactions among organisms and their environments.

• Population: Group of individuals of the same species in an area.

• Community: All populations in a given area.

• Biotic and Abiotic Factors: Living and nonliving components of ecosystems.

• Food Webs: Show energy flow and trophic relationships.

Animal Structure and Function

Comparative Anatomy and Physiology

Animals have diverse structures and physiological adaptations.

• Differences in Plant and Animal Cells: Plant cells have cell walls and chloroplasts; animal cells do not.

• Organ Systems: Examples include circulatory, respiratory, nervous, and digestive systems.

• Homeostasis: Maintenance of stable internal conditions.

Genetic Disorders and Human Genetics

Inheritance Patterns and Disease

Genetic disorders can be inherited in various ways.

• Autosomal Dominant: Only one copy of the mutant allele needed for expression.

• Autosomal Recessive: Two copies of the mutant allele needed.

• X-linked: Associated with genes on the X chromosome.

Evolutionary Relationships

Phylogeny and Classification

Phylogenetic trees show evolutionary relationships among species.

• Cladistics: Classification based on shared derived characteristics.

• Karyotype: Chromosomal composition of an organism.

• Speciation: Formation of new species through evolutionary processes.

Additional info:

• Some topics (e.g., animal phyla, ecological relationships) were expanded for completeness.

• Tables were inferred and reconstructed for clarity.