M4 - Genetics

• MENDELIAN GENETICS
• DNA REPLICATION
• DNA Replication


  1. Initiation

  2. Elongation

  3. Termination
• Helicases


  Unwind DNA double helix
• Single Stranded Binding Protein


  Binds to and stabilizes single-stranded DNA
• Primase


  Synthesizes RNA primers
• RNA Primer


  Short RNA sequence that provides a starting point for DNA synthesis
• DNA Polymerase 3


  Synthesizes new DNA strand
• Leading Strand


  DNA strand synthesized continuously
• Lagging Strand


  DNA strand synthesized discontinuously in Okazaki fragments
• Okazaki Fragment


  Short DNA fragments synthesized on the lagging strand
• DNA Polymerase 1


  Fills in gaps between Okazaki fragments
• Ubiquitin Ligase Complex


  Marks proteins for degradation
• CELL DIVISION
• Mitosis


  1. Interphase

  2. Prophase

  3. Metaphase

  4. Anaphase

  5. Telophase

  6. Cytokinesis
• Meiosis I


  1. Interphase

  2. Prophase

  3. Metaphase

  4. Anaphase

  5. Telophase

  6. Cytokinesis
• Meiosis II


  Four non-identical, haploid daughter cells<|>Two identical, diploid daughter cells
• Life of Gregor Mendel
• Gene


  A unit of heredity; a section of DNA sequence encoding a single protein
• Genome


  The entire set of genes in an organism
• Alleles


  Two genes that occupy the same position on homologous chromosomes and that cover the same trait
• Locus


  A fixed location on a strand of DNA where a gene or one of its alleles is located
• Genotype


  The genetic makeup of an organism
• Phenotype


  The physical appearance of an organism (Genotype + environment)
• Dominant Allele


  Stronger allele that expresses its phenotype in both heterozygous and homozygous states
• Recessive Allele


  Weaker allele that expresses its phenotype in homozygous state only when dominant allele is absent
• Homozygous


  Having identical genes (one from each parent) for a particular characteristic
• Heterozygous


  Having two different genes for a particular characteristic
• Punnett Square


  A useful tool to do genetic crosses
• Monohybrid Cross


  • Crossing two pea plants that differ in stem size, one tall one short
• Mendel's Principles
• Principle of Dominance


  One allele conceals another, one allele is dominant over the other in the F1 generation
• Principle of Segregation


  Every organism has two factors (genes) for each trait, one inherited from each parent, which separate during gamete formation and recombine during fertilization
• Principle of Independent Assortment


  The factors for different traits are distributed to sex cells (and offspring) independently of one another
• Human Case: Cystic Fibrosis

  • A lethal genetic disease affecting Caucasians, caused by a mutant recessive gene
• Dihybrid Cross


  Matings that involve parents that differ in two genes (two independent traits)