BIO 304 Genetics Exam #2 Name____KEY__________________ SSN____________________________ incomplete dominance conditional mutation penetrance expressivity Southern blotting hybridization epistasis co-dominance nonsense mutation translocation syngamy transformation missense mutation clone vector crossover electrophoresis nitrocellulose â-galactosidase ampicillin transduction silent mutation prototroph polymerase reverse transcriptase heterokaryon bacteriophage duplication auxotroph plasmid probe restriction enzyme lytic transversion episome suppression lysogeny complementation stringency dideoxy sequencing Northern blotting library inversion F factor pleiotropy PCR ligase polymorphism frameshift Prozac expression vector independent assortment conjugation reversion cDNA Ti plasmid sister chromatids RFLP biotechnology heteroduplex DNA complementation nonsense suppressor transition tautomeric shift thymine dimers intercalating agent polyploid aneuploid temperate phage prophage loss-of-function gain-of-function Use one of the above terms to best complete each sentence #1-15 below. (2 pts. each) 1. Crossing two mutants to determine whether the mutations are in the same gene is called a ___complementation______________ test. 2. A mutation within the anticodon of a tRNA that leads to insertion of an amino in response to an UGA, UAA, or UAG codon is called a ____nonsense suppressor_____________ . 3. ______Ti plasmid____________ is a chromosomal element from Agrobacterium that is used to genetically engineer plants. 4. A ______missense__ mutation results in substitution of one amino acid for another in a protein. 5. ___penetrance________ is the measure of the frequency with which a particular genotype results in its corresponding phenotype. 6. When expression of one gene masks expression of a non-allelic gene, we call that interaction ______epistasis_______________. 7. _____pleiotropy______________ is the phenomenon whereby a change of one gene has multiple phenotypic consequences. 8. ______transduction__________ is transfer of genes among organisms by viruses or virus particles. 9. _________RFLP_______________ is a polymorphism in which distance between two restriction sites varies, which can be used to map other genes.10. ___Southern blotting______ is the technique whereby DNA fragments are transferred from an electrophoretic gel to a nitrocellulose membrane. 11. Some viruses can integrate and maintain their genomes in host cell genomes, a process we call ___lysogeny__________________. 12. ___reverse transcriptase_____________ is a DNA polymerase that utilizes an RNA template. 13. A karyotype that lacks a chromosome (2n - 1) is a type of ___aneuploid___________ genome. 14. Most recombinant DNA clones consist of a _______vector__________________ sequence (for propagation in a host cell) and the DNA fragment that has been “cloned”. 15. A _____library_________________ is a collection of DNA clones. * * * * * * * * * * * * * 16. Consider the following two non-homologous chromosomes I and II, with genes a-j and centromeres represented by the small white squares: a b c d e f g h i j I II Draw a diagram of each of the following chromosome rearrangements (2 pts. each): a. A deletion of genes c and d a b e b. A reciprocal translocation a b c g f e d h i j c. A pericentric inversion of chromosome II f g i h j 17. Two phenotypically wild-type fruit flies were crossed, resulting in 88 females and 43 male progeny. Provide a brief explanation of this result. (4 pts.) The female was heterozygous for a sex-linked lethal gene, resulting in lethality of half of her sons. 18. Damage that results in distortion of the DNA helix is often repaired by the general excision repair pathway, that involves at least three distinctive steps. Briefly describe the steps of this pathway. (5 pts.) a. The repair components recognize the distortion and create endonucleolytic cleavages on either side of the defective DNA strand; the fragment is removed. b. DNA polymerase synthesizes a replacement strand, using the “good” strand as template. c. DNA ligase covalently closes the gap at the 3´ end of the new DNA.19. The following pedigree records transmission of two genes in dog: the dod gene, responsible for a recessive genetic disease, and an RFLP locus with haplotypes producing an 8 kb or 6+2 kb DNA fragments. A cross was carried out between a phenotypically dod female and male from a pure-breeding normal strain. F1 males and females were crossed, producing an F2 that included 12 puppies. a. Are the dod and RFLP loci linked? (3 pts.) Yes (most dod individuals are 6+2 / 6+2; most dod+ individuals received the 8 haplotype) b. What is the most likely genotype (for both dod and the RFLP locus) for dog #12? (3 pts.) Probably dod / dod+ and certainly 8 / 6+2 c. What advice would you provide the owner of dog #11 pertaining to the likelihood that this animal is a carrier for dod? (3 pts) Probably not a carrier, but there is some chance that he is, due to crossingover 20. You are called in as an expert witness in a legal case to determine whether a man of blood group A is the father of a child of blood group B. The child’s mother is blood group B. Do you advise the court that the father is / could be / cannot be the father of this child? Using diagrams, explain your conclusion. (5 pts.) Man could be the father, if he is heterozygous IA / i and contributed the i allele to the child. The cross could have been: IA /i man X IB /_ woman IB / i child 21. What are the karyotopes associated with each of the following syndromes in humans, and what are the primary sexual phenotypes associated with each: (2 pts. each) a. Turner syndrome XO female b. Klinefelter syndrome XXY male c. Down syndrome trisomy-21; can be either sex, depending upon sex chromosomes22. From a single F+ strain of E. coli that was entirely wild-type for most genes, five different Hfr strains are obtained. Each strain was crossed to a multiple-mutant F- strain, using the conjugation-disruption technique. It was found that each Hfr strain transferred genes in the order shown: Hfr strain A mal+ strS ser+ ade+ his+