Biology Exam 3 Study Guide PDF

**Biology Exam 3 Study Guide** **Module 7: Biotechnology** **Biotechnology Definition and Examples** Definition: The use of living organisms or their components to produce useful products Examples: Genetic engineering Fermentation Vaccine production Enzyme production **Important Processes i...

**Biology Exam 3 Study Guide** **Module 7: Biotechnology** **Biotechnology Definition and Examples** Definition: The use of living organisms or their components to produce useful products Examples: Genetic engineering Fermentation Vaccine production Enzyme production **Important Processes in Biotechnology** Chop: Using restriction enzymes to cut DNA at specific sequences Amplify: Making multiple copies of DNA using PCR (Polymerase Chain Reaction) Insert: Introducing DNA into host cells using vectors like plasmids Grow: Culturing modified organisms to produce desired products **CRISPR** Definition and Overview: Gene-editing technology that acts like molecular scissors Uses Cas9 enzyme to cut DNA at specific locations Allows precise modification of genes Risks of CRISPR: Off-target effects (unintended DNA modifications) Potential ecological impacts Ethical concerns about human germline editing **Agriculture** Genetic Engineering: Direct manipulation of an organism\'s genes Introduction of desired traits Recombinant DNA Technology: Combining DNA from different sources Creating organisms with new genetic combinations Factors Driving Modified Crop Adoption: Insecticides/Insect Resistance: Crops engineered to produce their own pesticides Reduced need for chemical spraying Herbicide Resistance: Crops tolerant to specific herbicides Allows better weed control Rewards vs. Risks: Transgenic Salmon Example: Faster growth rate Concerns about ecological impact Featherless Chicken Example: Easier processing Animal welfare concerns GMO Concerns: Environmental impact Gene transfer to wild species Food safety Biodiversity loss **Human Health** Treat vs. Prevent and Cure: Treatment: Managing symptoms Prevention: Stopping disease before it occurs Cure: Eliminating disease completely Applications: Diabetes: Synthetic insulin production Human Growth Hormone: Treatment for growth disorders Gene Therapy: Direct modification of genes to treat diseases Poor success record due to: Immune responses Difficulty targeting specific cells Complex nature of genetic diseases Genetic Testing: Parental carrier testing Prenatal diagnosis Predictive testing for late-onset conditions **Forensic Science** DNA Sequences in Humans: 99.9% identical between individuals 0.1% variation makes each person unique STRs (Short Tandem Repeats): Repeated DNA sequences Vary between individuals Used for identification DNA Fingerprinting: Pros: Highly accurate Small sample needed Long-term stability Cons: Cost Privacy concerns Processing time **Module 8: Genes and Inheritance** **Key Definitions** Heredity: Transmission of traits from parents to offspring Dominant vs. Recessive Traits: Dominant: Expressed when only one copy is present Recessive: Expressed only when two copies are present Test-cross: Crossing with homozygous recessive to determine genotype Pedigrees: Family trees showing inheritance patterns Incomplete Dominance: Neither allele completely dominant Codominance: Both alleles expressed equally Polygenic Traits: Traits influenced by multiple genes Additive Traits: Genes have cumulative effect Pleiotropy: One gene affecting multiple traits (e.g., Marfan syndrome) Phenotypes: Observable characteristics Dihybrid: Cross involving two traits Independent Assortment: Random separation of different gene pairs Linked Genes: Genes close together on same chromosome **Mendel\'s Research** Critical Features: Pure-breeding plants Controlled breeding Statistical analysis Important Ideas: Traits are controlled by factors (genes) Factors come in pairs Factors separate during gamete formation Law of Segregation: Allele pairs separate during gamete formation Each gamete receives one allele **Using Punnett Squares** Tool for predicting offspring genotypes Shows all possible combinations of gametes Helps calculate probability of traits **Module 9: Evolution** **Darwin\'s Contributions** Observed Patterns: Variation within species Fossil evidence Geographic distribution Origin of Species: Common descent Natural selection Gradual change **Evolution Mechanisms** Mutations: Random genetic changes Source of new alleles Can be beneficial, harmful, or neutral Genetic Drift: Random changes in allele frequencies Founder Effect: Small group establishes new population Bottleneck Effect: Population severely reduced Gene Flow: Movement of genes between populations Migration and interbreeding Natural Selection: Conditions: Variation exists Traits are heritable Differential reproduction Fitness Elements: Survival Reproduction Resource acquisition Sexual Selection: Mate choice Competition for mates **Types of Selection** Directional: Favors one extreme Stabilizing: Favors intermediate traits Disruptive: Favors both extremes **Evidence for Evolution** Fossil Record: Radiometric dating determines age Fossilization preserves remains Missing links show transitions Biogeography: Geographic distribution of species Example: Marsupial distribution Comparative Anatomy/Embryology: Homologous Structures: Same origin, different functions Vestigial Structures: Reduced, non-functional Convergent Evolution: Similar traits in unrelated species Molecular Biology: DNA/protein similarities Genetic code universality Laboratory/Field Studies: Observable evolution Experimental evidence