Lecture 1 Introduction Genotypes produce phenotypes phenotypes population characteristics DNA transcription RNA translation Protein Lecture 2 Mendel Part 1 o DNA RNA proteins protein interactions cell phenotypes organism True Breeding self fertilized plants produce only progeny like themselves Reciprocal Cross outcome of the cross is independent of whether the trait came from the male or female parent Principle of segregation Genes separate segregate into reproductive cells one to each o Gametes unite at random in fertilization Test Cross cross between a dominant phenotype and a recessive phenotype for the purpose of determining the genotype of the dominant phenotype individual Dihybrid an F1 individual hybrid for two characteristics o Phenotype ratios in a dihybrid cross are 9 3 3 1 Addition Rule the probability of one or the other of two mutually exclusive possibilities A or B is the sum of their separate probabilities Multiplication Rule the probability of two independent possibilities A and B occurring at the o Prob A or B Prob A Prob B same time o Prob A and B Prob A x Prob B Transposable element motile DNA element that can hop in and disrupt a gene DNA gel electrophoresis a method for separating DNA molecules by size Lecture 3 Mendel Part 2 Autosomal Recessive Inheritance the trait affects both sexes o Most affected persons have parents who are not affected Parents are heterozygous for recessive allele carriers Autosomal Dominant Inheritance the trait affects both sexes o Every affected person has affected parent Incomplete Dominance phenotype of heterozygous genotype is intermediate between the phenotypes of the homozygous genotypes Codominance the heterozygous genotype exhibits the traits associated with both homozygous genotypes o More frequent for molecular traits than for morphological traits Multiple Alleles presence in a population of more than two alleles of a gene Penetrance the proportion of individuals whose phenotype matches their genotype for a given tait o Incomplete penetance discrete categories are defined Rolling and not yellow or green round or wrinkled Lecture 5 Meiosis and Mitosis Mitosis process of chromosome segregation and cell division that results in two genetically identical diploid daughter cells o S or DNA Synthesis 9 hrs G2 Post DNA Synthesis 4 hrs Mitosis 1 hr G1 Pre DNA Synthesis 10 hrs Interphase chromosomes are not lined up and are not as condensed Stages of Mitosis o Prophase chromosomes condense Chromatids are attached to the centromere o Metaphase mitotic spindle forms and attaches to the chromatids near the centromere at a structure called a kinetochore Chromosomes move to the metaphase plate Proper chromosome alignment is essential o Anaphase centromeres divide Sister chromatids separate and move to opposite poles o Telophase and cytokinesis nuclear membrane forms around each compact group of chromosomes Chromosomes become de condensed In cytokinesis the cell divides to from two daughter cells Meiosis the process of chromosome segregation and cell division that results in four haploid daughter cells o Meiosis 1 four stages Prophase 1 chromosomes condense pair and cross over Metaphase 1 bivalents align at the center Anaphase 1 chromosomes separate to the poles Telophase 1 cell gets set up for Meiosis II o Meiosis II four stages Prophase II spindle reforms Metaphase II chromosomes align Anaphase II chromosomes separate Telophase II cells divide nuclei re form Lecture 6 Chromosome Structure Heterochromatin in interphase these regions are compact o Few genes and long stretches of repeat sequences called satellite DNA Euchromatin condense only during mitosis or meiosis o Contains many active genes in interphase Telomere essential for maintenance of chromosome ends Centromere essential for proper chromosome segregation Nondisjunction two chromosomes fail to separate from each other during meiosis o One cell gets two copies while the other cell gets zero Lecture 8 Linkage and Mapping Genes can be linked if they are located in close proximity on the same chromosome Crossing over of homologous chromosomes in Prophase I of Meiosis causes gene combinations to recombine and produces different allele combinations than parental types o This is called Recombination Frequency of recombination serves as a measure of genetic distance between genes and allows us to construct genetic maps Cis or coupling configuration the wild type alleles are on one chromosome and the mutant alleles are on the other chromosome Trans repulsion configuration each chromosome has one wild type and one mutant allele Parental types are the allele combos that match the parent s chromosomes o Always be the most common types Recombinant types are allele combos produced by crossing over o Least common types Recombination frequency recombination total o Max is 50 percent between any two genes Lecture 9 Recombination and DNA Polymorphisms Polymorphism a genetic difference that is relatively common in a population o Provide convenient genetic markers on each of the chromosomes Restriction enzymes are proteins that cut DNA at specific sequences DNA polymorphisms are phenotypes that can be used to map genes just like visible phenotypes Lecture 10 Chromosome Behavior Dosage compensation adjusts for differences in the numbers of sex chromosomes o Barr Body inactivated X chromosome Trisomy a third copy of one of the chromosomes Aneuploidy not having the same number of each chromosome Polyploidy an extra set or 2 of ALL of the chromosomes Monosomy only one of a particular chromosome Univalent one chromosome is unpaired Trivalent two chromosomes try and pair up with one chromosomes o Either way abnormal gametes result Duplications are caused by unequal cross over Crossing over within the inversion loop results in acentric and dicentric chromatids o Acentric lack centromeres o Dicentric two centromeres Translocations chromosomal abnormalities which occur when chromosomes break and the fragments rejoin to other chromosomes Lecture 11 DNA chemistry and DNA replication DNA is comprised of o A sugar deoxyribose o Phoshporic acid o And 4 nitrogen containing bases Purines adenine and guanine Pyrimidines cytosine and thymine The 5 phosphate is chemically linked to the 3 OH of the next nucleotide o Antiparallel the arrangement of the two strands in a double helix Bases pair through hydrogen bonding o Hydrogen bonds weak bonds in which F O or N share a hydrogen atom A T form two and G C form three