General Biology 2 Third Quarter Examination Reviewer PDF

General Biology 2 – Third Quarter Examination Reviewer I. Recombinant DNA (rDNA) 1. Definition of Recombinant DNA rDNA is artificially formed DNA by combining genetic material from different organisms. Used in biotechnology, medicine, agriculture, and research. 2....

General Biology 2 – Third Quarter Examination Reviewer I. Recombinant DNA (rDNA) 1. Definition of Recombinant DNA rDNA is artificially formed DNA by combining genetic material from different organisms. Used in biotechnology, medicine, agriculture, and research. 2. Tools Used in Recombinant DNA Restriction Enzymes (Endonucleases): Cut DNA at specific sites. Ligases: Join DNA fragments. Vectors: Carriers of foreign DNA (e.g., plasmids, bacteriophages). Polymerase Chain Reaction (PCR): Amplifies DNA. Electrophoresis: Separates DNA fragments. 3. History of rDNA in the Laboratory Paul Berg (1972): First scientist to create rDNA, combining bacterial and viral DNA. Stanley Cohen & Herbert Boyer (1973): Developed genetic engineering by inserting rDNA into bacteria using plasmids. 4. Steps/Process of Recombinant DNA 1. Isolation of desired gene. 2. Cutting DNA using restriction enzymes. 3. Insertion of gene into vector (plasmid/virus). 4. Introduction (Transformation) into host cell. 5. Cloning and Selection of successfully modified cells. 6. Expression of the inserted gene. 5. Process of Insertion of rDNA Transformation: Uptake of foreign DNA by a bacterial cell. Vectorless Gene Transfer: Electroporation: Electric pulses create pores in cell membranes for DNA entry. Protoplast Fusion: Enzyme removes cell wall, allowing fusion of different cells. Microinjection: Directly injecting DNA into the nucleus. Transduction: Viral-mediated transfer of DNA into a host cell. 6. rDNA in Health, Medicine, Agriculture, Environment, and Industry Gene Therapy: Correcting genetic disorders (e.g., CRISPR). Agriculture: GMOs for pest resistance, drought tolerance. Environment: Bioremediation (bacteria degrading pollutants). Industry: Production of insulin, vaccines, and enzymes. II. History of Life on Earth 1. Nicholas Steno & the Principle of Faunal Succession Nicholas Steno: Father of geology, proposed the law of superposition. Principle of Faunal Succession: Fossils appear in a specific sequence in rock layers, helping date Earth’s history. 2. Geological Eras Precambrian (Longest Era): Formation of Earth, first life (bacteria). Paleozoic: Age of jawless fishes, first land plants, and early reptiles. Mesozoic (Age of Reptiles): Dinosaurs dominated, first birds and mammals appeared. Cenozoic (Age of Mammals): Mammals flourished, modern humans appeared. 3. Formation of Mountain Ranges Result of plate tectonics and continental drift, forming the Himalayas, Andes, etc.  III. Relevance, Mechanism, and Evidence of Evolution 1. Mechanisms of Evolution Genetic Drift: Random changes in allele frequency. Mutation: Source of genetic variation. Natural Selection: Survival of the fittest. Gene Flow: Exchange of genes between populations. Recombination: Shuffling of genes during reproduction. 2. Evidences of Evolution Fossils: Show transitional species. Comparative Embryology: Similar embryonic stages suggest common ancestry. Anatomical Evidence: Homologous Structures: Similar structure, different function (e.g., human arm and whale flipper). Analogous Structures: Different structure, same function (e.g., bird wing and butterfly wing). Biochemical Evidence: DNA/protein similarities show common ancestry. Biogeography: Distribution of species supports evolution. 3. Scientists with Evolutionary Thought Charles Darwin: Theory of Natural Selection. Jean-Baptiste Lamarck: Theory of Acquired Characteristics. Alfred Russel Wallace: Independently proposed natural selection. IV. Taxonomy and Systematics  1. Definition of Taxonomy and Systematics Taxonomy: Science of classifying organisms. Systematics: Study of evolutionary relationships among organisms. 2. Carl Linnaeus and His Classification System Father of modern taxonomy. Developed the binomial nomenclature (Genus species). 3. Cladistics and Cladograms Cladistics: Classification based on common ancestry. Cladogram: Diagram showing evolutionary relationships. 4. Phylogenetic Tree Represents evolutionary history and divergence of species. 5. Three Domains of Life Bacteria: Prokaryotic, unicellular, no nucleus. Archaea: Prokaryotic, survive in extreme environments. Eukarya: Have a nucleus, include plants, animals, fungi, protists.