BIO 305 1st EditionExam 1 Study Guide: Lectures 1 - 7Lecture 1Introduction to GeneticsDescribe chromosomal structure: where is the telomere, centromere, and kinetochore? Which is the p-arm and q-arm? (Hint: P for Petite) What is the difference between a homologous chromosome and sister chromatids? (Hint: what is the difference between chromosomes and chromatids? Which are pulled apart in Mitosis? Meiosis II or I? Be able to visualize them)Centromere Location: Submetacentric (between middle and end), Metacentric (middle), Acrocentric (close to the end), Telocentric (at the end)Germ Cells (diploid/haploid) – be able to do problems is given the diploid or haploid number of an organism and asked how many structures there may be at different stages of division or fertilizationThe Cell Cycle: Interphase  (S)  (G2)  Mitosis (Prophase, Metaphase, Anaphase, Telophase)  (G1) (Some cells undergo a special stage: (G0) – non-dividing cell phase after G1)What are the three checkpoints for regulation? What do they regulate?Mitosis vs. Meiosis – very important to know this! Know every stage of I-P-M-A-T. What are the differences between the two (How many chromosomal structures (n) at each stage in each cell?How are the chromosomes aligned in the center of the cell, pre-division? Which undergoes synapsis? Can you draw PMAT?Disjunction – be able to state how many chromosomal structures are in each phase of oogenesisin both disjunction (normal) and non-disjunction (How many in the primary oocyte? Second polar body? Mature ovum? What if there is non-disjunction in first division? Second division?Lecture 2 Briefly know the various scientists covered (see scientists section below) and what they contributed to genetics: especially Mendel and T. H. Morgan. Know the diseases (see diseases below) and briefly what causes themWhat was Mendel’s experiment and why did it succeed? Why do we do a test-cross? What is thedifference between selfing vs. crossing?What are Mendel’s four postulates of inheritance? What do they mean? Where in the cell at what stage do laws #3 and #4 arise? (aka what is the molecular explanation?)Understand how to analyze crosses involving multiple contrasting traits: dihybrid cross or forked-line diagram. Be able to recognize reoccurring ratios and the ratios within the ratios (for example, how can the 3:1 ratio be seen in the dihybrid cross having a 9:3:3:1 ratio? If you look at the traits separately, can see that the 3:1 ratio applies to each)What are the four laws of probability? When do you use them? (For example, you use binomial theorem when the order of the phenotypes of resulting progeny matters)Statistics: Know how to take a chi-square test, find the degrees of freedom, find p-value from the chart (will be given on exam) and know what these values mean for rejecting/accepting the null hypothesis. What are the two reasons for you to reject the null hypothesis? Accept? If p < 5% / .05, REJECT null hypothesisLecture 3Pedigrees:1) Before anything, look at the patterns of inheritance to distinguish how the observed trait is inherited. If it is rare or skips a generation, there is a high likelihood it is recessive (unless we are looking at bloodtype). Next, check to see if it is X-linked. If it is 50/50, then it is autosomal. If it is mostly males are affected, X-linked recessive, if it is about 1/3 male and 2/3 female, X-linked dominant. Again, these are rules of thumb.2) Know try to write the genotypes for important individuals on the pedigree. Fill in the homozygous recessive genotypes first, because they are the easiest. Homozygous dominant vs. heterozygous is trickier. Remember that in order for a child to have a recessive trait, both parents usually have to be a carrier (and vice versa).3) Lastly, you will usually be asked a probability question based on what you have figuredout for yourself (i.e. what are the chances individual II.a and III.v have an affected boy, etc.) Recall that you often must consider the likelihood that the parents are a carrier AND the chances that they will pass it on. Don’t forget to include the ½ factor if the gender of the child matters.Dominance:Be able to recognize full dominance, partial dominance (often characterized by a 1:2:1 ratio), co-dominance (ex: bloodtype). Understand how bloodtypes work:Multiple Gene Interaction: Be able to recognize modified dihybrid ratios and be able to attributethem to different possible causes (what is the gene pathway?)Lecture 4What did T.H. Morgan find in his experiments? Why are drosophila model organisms?3 X-linked Inheritance Rules: 1) Y is ALWAYS paternally transmitted2) For a male, the X comes from the mother: MOM  Son’s X3) For a female, receives an X from both parents: MOM + DAD  Daughter’s XXWhat were C. B. Bridges’ findings? Know the outcome of disjunction in sex chromosomes. ¼ Drosophila: XX/X, which is lethal in flies (not humans!) so they died¼ Drosophila X/0, which results in sterile males¼ Drosophila XX/Y resulted in white-eyed females, because the two X chromosomes came from the mother¼ Drosophila 0/Y, also lethalBe able to describe how chromosomal diseases (such as XXY) occurs as a result of nondisjunction.How might lethal alleles or genotypes explain unexpected ratios you might see?Understand imprinting (the expression of a trait depends on whether the trait has been inherited from a male or female parent), which often results in the silencing of certain phenotypes depending on the gene inherited by the mother.X-linked dominant diseases: If a male is affected, ALL daughters are affectedIf a female is affected, half the kids are affected (only one X from mom)Lecture 5Chromosome mapping (what would happen if you have complete linkage? All the genes are inherited together and expect a 1:1:1:1 ratio. If there is linkage? Then 2 parental (non-crossover gametes) occur along with 2 recombinant gametes)Recombination rate = proportion of recombinants (Why is the maximum 50%? Why does distance apart affect the rate of recombination? Hint: think of potential area on the chromosome in which crossover can occur)The higher frequency of recombinance = distance between genes is larger = likelihood of incomplete linkage% of tetrads involved in an exchange between two genes = 2*recombination rateThis is important to use when given the map distance between two genes and asked for how many phenotypes will result after n number of progeny produced (where the