General Terminology and Key Concepts

Introduction

This study guide covers essential terms and concepts for a comprehensive General Biology final exam. It is organized by major topics, with definitions, explanations, and examples to support your understanding.

Characteristics of Life and Classification

Characteristics of Life

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

• Metabolism: All living things carry out chemical reactions (anabolism and catabolism).

• Homeostasis: Maintenance of a stable internal environment.

• Growth: Increase in size and number of cells.

• Reproduction: Ability to produce new organisms.

• Response to Stimuli: Reacting to environmental changes.

• Evolution: Populations change over generations.

Classification of Life

• Domains: Bacteria, Archaea, Eukarya

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

The Scientific Method

• Observation: Gathering information about phenomena.

• Hypothesis: A testable explanation for an observation.

• Experimentation: Testing the hypothesis under controlled conditions.

• Analysis: Interpreting data to draw conclusions.

• Conclusion: Accepting, rejecting, or modifying the hypothesis.

Macromolecules

Hydrolysis Reactions

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

• Example: Digestion of starch into glucose.

Types of Carbohydrates

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

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

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

Cell Structures

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 DNA, controls cell activities.

• Mitochondria: Site of cellular respiration and ATP production.

• Ribosomes: Protein synthesis.

• Endoplasmic Reticulum (ER): Rough ER synthesizes proteins; Smooth ER synthesizes lipids.

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

• Lysosome: Digests macromolecules.

• Peroxisome: Breaks down fatty acids and detoxifies substances.

• Plasma Membrane: Regulates entry and exit of substances.

• Histones: Proteins that package DNA in the nucleus.

Process of Creating and Secreting Proteins

• DNA (in nucleus) → mRNA (transcription) → Ribosome (translation) → Protein enters ER → Modified in Golgi → Secreted via vesicles.

Plasma Membrane

Types of Transport Across Membranes

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

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

Metabolic Respiration

Steps of Cellular Respiration & ATP Production

• Glycolysis: Occurs in cytoplasm; glucose → 2 pyruvate, 2 ATP, 2 NADH.

• Citric Acid Cycle (Krebs Cycle): In mitochondria; produces 2 ATP, 6 NADH, 2 FADH2 per glucose.

• Oxidative Phosphorylation: Electron transport chain and chemiosmosis; produces ~34 ATP.

• Total ATP Yield: Up to 38 ATP per glucose (theoretical maximum).

Key Enzymes

• ATP Synthase: Enzyme that synthesizes ATP from ADP and Pi using the proton gradient.

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 progression through the cell cycle.

DNA Replication

Steps of DNA Replication and Repair

• Initiation: DNA unwinds at origins of replication.

• Elongation: DNA polymerase adds nucleotides to new strand.

• Termination: Replication ends; DNA ligase joins fragments.

• Repair: Proofreading and repair enzymes correct errors.

Key Enzymes

• DNA Polymerase: Synthesizes new DNA strands.

Protein Synthesis

Overview

• Transcription: DNA → mRNA (by RNA polymerase).

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

Steps of Translation

• Initiation: Ribosome assembles at start codon of mRNA.

• Elongation: tRNAs bring amino acids; peptide bonds form.

• Termination: Stop codon reached; protein released.

Mitosis and Meiosis

Phases of Mitosis

• Prophase: Chromosomes condense, spindle forms.

• Metaphase: Chromosomes align at cell equator.

• Anaphase: Sister chromatids separate.

• Telophase: Nuclear envelope reforms.

• Cytokinesis: Division of cytoplasm.

Diploid and Haploid Cells

• Diploid (2n): Two sets of chromosomes (somatic cells).

• Haploid (n): One set of chromosomes (gametes).

Genetics

Genetic Terminology

• Allele: Different forms of a gene.

• Dominant/Recessive: Dominant alleles mask recessive ones.

• Homozygous: Two identical alleles.

• Heterozygous: Two different alleles.

Types of Inheritance Patterns

• Complete Dominance: One allele completely masks another.

• Incomplete Dominance: Heterozygote shows intermediate phenotype (e.g., pink flowers from red and white parents).

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

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

• Sex-linked/X-linked: Genes on sex chromosomes; often affect males more (e.g., hemophilia).

Chromosome Abnormalities

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

• Deletion: Loss of chromosome segment.

• Translocation: Segment moves to another chromosome.

Punnett Squares

• Used to predict genotypes and phenotypes of offspring.

• Monohybrid: One trait; Dihybrid: Two traits.

Pedigree Charts

• Used to track inheritance patterns in families.

Evolution

Evidence for Evolution

• Fossil record, comparative anatomy, molecular biology, biogeography.

Types of Anatomical Structures

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

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

• Vestigial: Reduced or unused structures.

Mechanisms of Evolution

• Natural Selection: Differential survival and reproduction.

• Genetic Drift: Random changes in allele frequencies (e.g., bottleneck effect, founder effect).

• Gene Flow: Movement of alleles between populations.

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 Homo Species

• Homo habilis, Homo erectus, Homo sapiens, Sahelanthropus tchadensis

Evolutionary Trees

• Diagram relationships among species based on common ancestry.

Population Dynamics

Key Terms

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

• Community: All populations in an area.

• Ecosystem: Community plus abiotic environment.

• Biotic Potential: Maximum reproductive capacity.

Population Growth Curves

• Exponential Growth: J-shaped curve; unlimited resources.

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

Population Calculations

• Growth Rate:

• Doubling Time (Rule of 72):

Carrying Capacity and Environmental Resistance

• Carrying Capacity (K): Maximum population size environment can support.

• Environmental Resistance: Factors that limit population growth.

Tissues

Classification and Types of Epithelial Tissue

• Simple Epithelium: One cell layer (e.g., simple squamous, cuboidal, columnar).

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

• Goblet Cells: Secrete mucus in epithelial linings.

Types of Junctions in Epithelial Tissue

• Tight Junctions: Seal cells together.

• Adhesion Junctions (Desmosomes): Anchor cells together.

• Gap Junctions: Allow communication between cells.

Classification and Types of Connective Tissue

• Fibrous Connective Tissue: Dense (tendons, ligaments) and loose (under skin).

• Special Connective Tissue: Cartilage, bone, blood, adipose tissue.

• Fibroblasts: Cells that produce fibers in connective tissue.

Types of 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/glands.

Additional Key Terms

• Basement Membrane: Thin layer anchoring epithelium to underlying tissue.

• Pangea: Ancient supercontinent.

• Catabolism: Breakdown of molecules for energy.

• Anabolism: Synthesis of complex molecules from simpler ones.

Sample Table: Types of Cell Junctions

Example Problem: Punnett Square for Monohybrid Cross

• Cross: Aa x Aa (A = dominant, a = recessive)

• Genotype Ratio: 1 AA : 2 Aa : 1 aa

• Phenotype Ratio: 3 dominant : 1 recessive

Additional info: This guide expands on the exam outline by providing definitions, explanations, and examples for each listed term and concept. For more detailed study, refer to your textbook chapters corresponding to each topic.