Gen-Bio 2: Genetics

• Gene is a unit of heredity
• Gene is a section of DNA sequence encoding a single protein
• Genome is the entire set of genes in an organism
• Alleles are two genes that occupy the same position on homologous chromosomes and cover the same trait like 'flavors' of a trait
• Locus is a fixed location on a strand of DNA where a gene or one of its alleles is located
• Homozygous is having identical genes, one from each parent, for a particular characteristic
• Heterozygous is having two different genes for a particular characteristic
• Dominant is the allele of a gene that masks or suppresses the expression of an alternate allele, the trait appears in the heterozygous condition
• Recessive is an allele that is masked by a dominant allele, does not appear in the heterozygous condition, only in homozygous
• Genotype is the genetic makeup of an organism
• Phenotype is the physical appearance of an organism, determined by the genotype and the environment
• Monohybrid cross is a genetic cross involving a single pair of genes, focusing on one trait
• Parents in genetics differ by a single trait
• P is Parental generation in genetics
• F1 is First filial generation offspring; offspring from a genetic cross
• F2 is Second filial generation offspring of a genetic cross
• From the past decades, human beings have looked for ways to improve the quality of their lives
• Humans have transitioned from being nomads to farmers and livestock raisers
• People practice artificial selection to develop and gain the best quality of organisms
• Scientists have developed genetic engineering to modify the genetic composition of organisms to possess desired traits or phenotypes
• Genetic engineering


  Cutting DNA sequences and pasting them on a new sequence to create an organism with specific traits
• Genetic engineering is similar to playing with LEGO blocks, where scientists build up DNA to create new organisms
• Genetic engineering


  • Also known as DNA technology
• DNA technology is widely used to engineer the genes of cultured cells for practical purposes
• Genetically engineered bacteria are a remarkable breakthrough of DNA technology
• Bacteria have three modes of gene transfer: transduction, transformation, and conjugation
• Plasmid


  A circular DNA molecule smaller than and separate from bacterial chromosomes, used in DNA technology
• Genetically engineered bacteria have applications in agriculture, pollution remediation, medicine, and hormone production
• Enzymes used for cutting and pasting DNA molecules

  Bacterial enzymes called restriction enzymes are used for cutting foreign DNA
• Creating recombinant DNA using restriction enzymes and DNA ligase

  Restriction enzymes cut DNA at specific sequences

  2. Many cuts result in restriction fragments

  3. Useful restriction enzymes cut DNA in a staggered way, producing fragments with 'sticky ends' that bond with complementary ends of other fragments

  4. DNA ligase seals the bonds between restriction fragments
• Making cloned genes in recombinant plasmids

  A challenging and tedious process involving multiple steps
• DNA technology including recombinant DNA technology and other methods for studying and manipulating DNA have changed the future of the human race
• New opportunities in fields due to DNA technology

  • Mass production of gene products
  • Pharmaceutical industry and medicine
  • Agriculture
• Production of Gene Products

  1. Recombinant cells and organisms modified by DNA technology are used to manufacture many useful products

  2. Bacteria are the best candidate for manufacturing a protein product due to advantages like plasmids, phages, rapid growth, and cost-effectiveness

  3. Eukaryotic cells like Saccharomyces cerevisiae or yeast are recommended for producing protein products

  4. Mammalian cells are required for certain protein products, and genes are often cloned in bacteria before transfer
• Protein products of recombinant DNA technology

  • Insulin
  • Growth hormone
  • Blood Clotting Factor VIII
• Pharmaceutical Industry and Medicine

  1. DNA technology has had a major impact on the pharmaceutical industry and human medicine

  2. Recombinant DNA technology has influenced therapeutic hormones, diagnosis and treatment of diseases, and vaccine development
• Insulin and growth hormone were the first pharmaceutical products made using recombinant DNA technology
• Before 1982, insulin was mainly sourced from pigs and cattle tissues, causing harmful side effects in some people
• Genetic engineering developed bacteria that synthesize and secrete human insulin, solving the side effects issue
• Growth hormone was produced in E. coli using an artificial gene developed through genetic engineering