Genetic Engineering Overview

Genetic Engineering

• Genetic engineering is the artificial manipulation, modification, and recombination of DNA molecules to modify organisms.
• Recombinant DNA technology uses enzymes and techniques to isolate and combine DNA segments from different species, or create genes with new functions.
• DNA recombination is the process of modifying an organism's genes for practical purposes by combining a piece of DNA with another from a different source.
• Recombinant DNA is the resulting genetic product.
• Recombinant DNA molecules from two different species are inserted into a host organism to produce new genetic combinations.
• This is useful for science, medicine, agriculture, and industry.

Processes Involved in Genetic Engineering

• Transformation using a vector: Recombinant DNA is created by taking help of vectors, such as bacterial cells. Vectors are organisms that can spread genetic material from one host to another.
• Electroporation (Electropermeabilization): An efficient method for delivering genetic material, proteins, drugs, or molecules into cells. It uses electrical pulses to temporarily create pores in the cell membrane, allowing molecules to pass.
• Protoplast fusion: Cells are treated with chemicals to initiate recombination. Bacterial cell walls are digested to form protoplasts.
• Microinjection: A method for immobilizing host cells and injecting foreign DNA using a microinjection needle to create recombinant DNA.
• Particle gun method: Host cells are bombarded with tungsten particles coated with foreign DNA. It's commonly used in agriculture.
• Transduction: Genetically engineered bacteriophages (viruses that infect bacteria) are introduced to create recombinant DNA in the target cell.

Genetic Engineering Techniques

• Artificial Selection: Breeders choose organisms to mate to produce offspring with desired traits. This technique doesn't control the genes passed. It includes selective breeding, hybridization, and inbreeding.
• Cloning: Creating an exact genetic copy of another organism. Clones are genetically identical groups of cells or organisms produced by asexual reproduction.

Types of Natural Selection

• Directional Selection: Favors extreme phenotypes, causing allele frequency to shift towards that phenotype.
• Stabilizing Selection: Maintains a population mean on a specific trait value.
• Disruptive Selection: Favors individuals at both extremes of a trait over those with the average phenotype.

Genetic Drift

• Founder Effect: A small group of individuals colonize a new habitat, leading to changes in allele frequencies due to random changes in the population.
• Bottleneck Effect: Sharp reduction in a population's size due to environmental events. Causes changes in allele frequencies due to random chance of survival.

Speciation

• Allopatric Speciation: Species separate into two isolated groups leading to speciation.
• Peripatric Speciation: A small group breaks off from a larger one into a new habitat, with a smaller group having significant differences from the group they separated from.
• Parapatric Speciation: Species spread over wide regions with mate selection between individuals in the same geographic regions.
• Sympatric Speciation: Controversial; believed to occur within the same geographic area.

Evolution of Evolutionary Thoughts

• Catastrophism: Natural history is punctuated by catastrophic events, influencing the development of life on earth and rock deposition.
• Gradualism: Profound changes to Earth occur gradually through time, shaping the Earth's landscape and evolution of species.
• Darwin's Theory of Evolution by Natural Selection: Species change over time as populations produce more offspring than can survive leading to the struggle for survival in which organisms more suited to the challenges will survive and reproduce, passing their favorable traits to the next generation.
• Artificial Selection: Demonstrating the ability of selection to affect the traits of organisms.

Evidence of Evolution

• Biogeography: The distribution of species on Earth in the past and present, influenced by abiotic factors like habitat, climate, & terrain.
• Fossil Record: Shows gaps in life's history that serve as evidence for mass extinctions.
• Comparative Anatomy: Study of body structures of different species to understand adaptive changes linked to a common ancestor.
• Homologous Structures: Similar structures in related organisms due to shared ancestry.
• Analogous Structures: Similar structures in unrelated organisms serving the same function.
• Vestigial Structures: Traits that no longer serve a function, but were present in ancestors.
• Physiology and Biochemistry: Shared molecules and biochemical mechanisms among organisms, revealing evolutionary links.
• Embryology: Similar developmental stages in embryos of different species, revealing evolutionary relationships.
• Phylogenetic Trees: Visual representations of evolutionary relationships among organisms.

Taxonomy

• Binomial Nomenclature: A standardized system for naming species using two names; the genus and species.
• Taxonomy: The science of classifying and naming organisms based on shared characteristics and relationships.
• Domains: The highest level of classification that includes Bacteria, Archaea, and Eukarya.
• Kingdoms: Subcategories of domains.
• Phyla: A higher taxonomic rank than class.
• Classes, Orders, Families, Genera, and Species: Taxonomic ranks in descending order of specificity.

Cladistics

• Cladistics: A method of classification based on derived traits & the relationships of organisms.
• Synapomorphies: Derived traits shared by all members of a clade (group of organisms).
• Monophyletic Group: Includes a common ancestor and all of its descendants.
• Paraphyletic Group: Includes a common ancestor but not all of its descendants.
• Polyphyletic Group: Does not include the common ancestor, grouping organisms based on similarities that have evolved independently.

This quiz explores the principles and processes involved in genetic engineering. Key concepts include recombinant DNA technology, DNA recombination, and the role of vectors in creating genetic modifications. Test your knowledge on how these techniques are applied in various fields such as medicine and agriculture.