General Terminology and Key Concepts

Overview

This study guide covers essential terms and concepts for a comprehensive General Biology final exam. It includes definitions, processes, and examples relevant to cell biology, genetics, evolution, population dynamics, and tissue classification.

Characteristics and Classification of Life

Characteristics of Life

• Organization: Living things are composed of one or more cells.

• Metabolism: All living things carry out chemical reactions to obtain and use energy.

• Homeostasis: Maintenance of a stable internal environment.

• Growth and Development: Organisms increase in size and complexity.

• Reproduction: Ability to produce new individuals.

• Response to Stimuli: Reacting to environmental changes.

• Evolutionary Adaptation: Populations change over generations.

Classification of Life

• Domains: Bacteria, Archaea, Eukarya

• Kingdoms: Examples include Animalia, Plantae, Fungi, Protista, etc.

The Scientific Method

Steps of the Scientific Method

• Observation

• Question

• Hypothesis: A testable explanation.

• Experiment

• Analysis

• Conclusion

Scientific Hypotheses: Must be testable and falsifiable.

Macromolecules

Hydrolysis Reactions

• Hydrolysis: Breaking down polymers into monomers by adding water.

Types of Carbohydrates

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

• Disaccharides: Two monosaccharides joined (e.g., sucrose).

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

Cell Structures and Functions

Cell Theory (The Cell Doctrine)

• All living things are made of cells.

• Cells are the basic unit of structure and function.

• All cells arise from pre-existing cells.

Advantages for Cells to Stay Small

• Higher surface area-to-volume ratio for efficient exchange of materials.

Structure & Functions of Organelles in Eukaryotic Cells

• Nucleus: Contains genetic material.

• Mitochondria: Site of ATP production.

• Ribosomes: Protein synthesis.

• Endoplasmic Reticulum (ER): Protein and lipid processing.

• Golgi Apparatus: Modifies and packages proteins.

• Lysosome: Digestion of macromolecules.

• Peroxisome: Breakdown of fatty acids and detoxification.

Process of Creating and Secreting Proteins

• DNA → mRNA (transcription in nucleus)

• mRNA → Protein (translation at ribosome)

• Protein processed in ER and Golgi, then secreted via vesicles.

Plasma Membrane and Transport

Types of Transport Across Membranes

• Passive Transport: Diffusion, facilitated diffusion, osmosis (no energy required).

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

Metabolic Respiration

Steps of Cellular Respiration & ATP Production

• Glycolysis: Glucose → 2 pyruvate, 2 ATP, 2 NADH

• Citric Acid Cycle (Krebs Cycle): Acetyl-CoA → CO2, NADH, FADH2, 2 ATP

• Oxidative Phosphorylation: Electron transport chain and chemiosmosis, produces most ATP

ATP Synthase: Enzyme that synthesizes ATP using the proton gradient.

Overall Equation:

The Cell Cycle

Steps of the Cell Cycle

• Interphase: G1 (growth), S (DNA synthesis), G2 (preparation for division)

• M Phase: Mitosis and cytokinesis

Cyclins: Proteins that regulate the cell cycle.

DNA Replication and Repair

Steps of DNA Replication

• Unwinding of DNA (helicase)

• Base pairing (DNA polymerase)

• Formation of new strands

• Proofreading and repair

DNA Polymerase: Enzyme that synthesizes new DNA strands.

Protein Synthesis

Transcription and Translation

• Transcription: DNA → mRNA (by RNA polymerase)

• Translation: mRNA → Protein (at ribosome, involving tRNA and rRNA)

Steps of Translation

• Initiation: Ribosome assembles at start codon.

• Elongation: Amino acids added to growing chain.

• Termination: Stop codon reached; protein released.

Mitosis and Meiosis

Phases of Mitosis

• Prophase

• Metaphase

• Anaphase

• Telophase

• Cytokinesis

Meiosis

• Reduces chromosome number by half; produces gametes.

Genetics

Types of Inheritance Patterns

• Complete Dominance: One allele masks another.

• Incomplete Dominance: Heterozygote shows intermediate phenotype.

• Co-dominance: Both alleles expressed equally (e.g., AB blood type).

• Polygenic Inheritance: Multiple genes affect a trait (e.g., skin color).

• Sex-linked/X-linked: Genes located on sex chromosomes.

Genetic Terminology

• Dominant/Recessive Alleles

• Homozygous: Two identical alleles

• Heterozygous: Two different alleles

Chromosome Abnormalities

• Nondisjunction: Failure of chromosomes to separate properly (e.g., Trisomy-X, Turner Syndrome)

• Deletion: Loss of chromosome segment

• Translocation: Segment moves to another chromosome

Punnett Squares

• Used to predict genotypes and phenotypes in crosses (monohybrid, dihybrid)

Pedigree Charts

• Used to trace inheritance patterns in families

Evolution

Evidence for Evolution

• Fossil record, comparative anatomy, molecular biology, biogeography

Anatomical Structures

• Homologous: Similar structure, different function (common ancestry)

• Analogous: Different structure, similar function (convergent evolution)

• Vestigial: Reduced or unused structures

Antigenic Shift

• Major change in viral antigens due to gene reassortment

Classification of Primates

• Hominoids: Apes and humans

• Hominids: Great apes and humans

• Hominins: Modern humans and extinct relatives

Key Evolutionary Differences Between Homo Species

• Homo habilis: Earliest tool use

• Homo erectus: First to use fire, migrate out of Africa

• Homo sapiens: Modern humans, advanced culture

Evolutionary Trees

• Show relationships among species; read from root to tips

Population Dynamics

Key Terms

• Biotic Potential: Maximum reproductive capacity

• Population: Group of individuals of same species

• Ecosystem: Community plus environment

• Community: All populations in an area

Population Growth Curves

• Exponential Growth: J-shaped curve, unlimited resources

• Logistic Growth: S-shaped curve, limited by carrying capacity

Population Dynamic Calculations

• Growth Rate:

• Doubling Time (Rule of 72):

Tissue Classification

Epithelial Tissue

• Simple: One layer (e.g., simple squamous)

• Stratified: Multiple layers (e.g., stratified squamous)

• Shapes: Squamous (flat), cuboidal (cube), columnar (tall)

• Goblet Cells: Secrete mucus

• Basement Membrane: Supports epithelium

Types of Junctions in Epithelial Tissue

Connective Tissue

• Fibrous Connective Tissue: Dense, provides support (e.g., tendons)

• Special Connective Tissue: Includes bone, cartilage, blood

• Fibroblasts: Cells that produce fibers

Muscle Tissue

• Skeletal Muscle: Voluntary movement

• Cardiac Muscle: Involuntary, heart only

• Smooth Muscle: Involuntary, walls of organs

Types of Neurons

• Sensory Neurons: Carry signals to CNS

• Motor Neurons: Carry signals from CNS to muscles

Additional Key Terms

• Catabolism: Breakdown of molecules for energy

• Anabolism: Synthesis of complex molecules

• Gene Flow: Movement of genes between populations

• Genetic Drift: Random changes in allele frequencies

• Bottleneck Effect: Population size reduction causes loss of diversity

• Founder Effect: New population started by few individuals

• Pangea: Ancient supercontinent

• Sahelanthropus tchadensis: Early hominin species

Example: In a monohybrid cross between two heterozygous pea plants (Yy x Yy), the Punnett square predicts a 3:1 ratio of yellow to green seeds.

Additional info: This guide expands on brief terms with academic context to ensure completeness for exam preparation.