BIO208 Bacterial Genetics Worksheet 1 1. Using standard bacterial genetic notation, write the genotypes of bacterial strains that have the following characteristics: a. unable to metabolize the sugar lactose (lac) b. able to make the amino acid leucine (leu) c. resistant to the antibiotic streptomycin (str) d. sensitive to the antibiotic puromycin (pur) 2. Is strain "a" in question #1 prototroph or an auxotroph? Strain "b"? (Assume the strains are wild type for all genes but the one in question). 3. Describe 5 steps involved in the lytic life cycle of bacteriophages. 4. Fill in Transformation Transduction Conjugation _______________a. naked DNA is involved _______________b. faulty head stuffing may occur _______________c. involves exconjugants _______________d. adsorption and injection of genetic material _______________e. competent cells required _______________f. an F plasmid encodes attachment proteins _______________g. used to construct the E. coli minute map _______________h. a pilus is produced _______________i. lytic cycle entered in response to stress _______________j. may be specialized or general _______________k. requires cell to cell contact _______________l. mediated by a virus _______________m. known as parasexual mating _______________n. requires competent cells _______________o. involves a phage 5. Fill in using this word bank homologous recombination extrachromosomally (episomally) F+ cell F Factor (plasmid) Hfr strain F minus (F-) generalized phage packaging lysogeny interrupted mating adsorption a. the reciprocal exchange of DNA between two DNA fragments of identical (or at least close to identical) sequences is called __________________________________ b. A plasmid can be maintained ______________ or integrate into bacterial chromosome. c. In ______________ transduction, all bacterial DNA has equal probability of being packaged. d. In ____________, phage genome integrates into bacterial genome creating a prophage. e. In _______________transduction, the phage excises, and may also clip bacterial genes f. The ________________ contains ~100,000 base pairs and contains 19 genes that encode for proteins involved in pili synthesis and other functions g. The F factor occasionally integrates randomly into the E. coli chromosome creating a (n) _______ h. In normal conjugation, recipient (female) cells remain __________ i. The __________________ technique involves conjugation and plating cells at different times j. After a phage engages in _____________, it will inject genetic material into bacterium k. Lambda bacteriophage assembles new virus during the process of ________________----BIO208 Bacterial Genetics Worksheet 2 6. What is the difference between: a. A bacterial colony and a lawn b. The log phase and the stationary phase of bacterial growth c. Minimal media and complete media d. A conditional mutant and a nutritional mutant e. Binary fission and parasexual mating f. A prototroph and an auxotroph g. A plasmid and a chromosome h. Generalized and specialized transduction i. A phage and a bacterium j. An F+, an Hfr, and an F- cell k. A donor and recipient cell l. A U tube and a blender m. Size of F factor and size of bacterial genome n. Lytic and lysogenic cycle o. A virulent and a temperate phage p. Prophage and phage q. Phage adsorption and phage packaging 7. What is the difference between a. operon inducer and repressor b. betagalactosidase and Z structural gene c. promoter and operator d. O and Oc e. I and I- f. lactose and glucose g. negative and positive operon regulation h. polycistronic and monocistronic (as in humans) mRNA i. constitutively expressed and regulated genes 8. Operons are found in (circle one) a. Prokaryotes b. Eukaryotes 9. Fill in using the following choices lactose repressor protein operator lac Z promoter beta galactosidase a. _____________________________ DNA that binds repressor to prevent transcription b. _____________________________ DNA that binds RNA polymerase c. _________________________ binds repressor to allow transcription d. _____________________________ a structural gene of the operon e. _____________________________ is bound by lactose f. _____________________________ a trans acting protein that represses the operon g. _____________________________ encoded by the I gene h. __________undergoes a conformational (shape) change which prevents binding to the operator i. _____________________________ gene that is actively transcribed when derepressed j. _____________________________ enzyme that cleaves lactose into glucose and galactose k. _____________________________ 3 DNA elements of the lac operon l. _____________________________ 2 proteins associated with the lac operon m. _____________________________ 1 sugar associated with the lac operonBIO208 Bacterial Genetics Worksheet 3 10. A normal bacterial cell is grown in lactose (sugar). The lac operon is: a. off (repressed) b. on (induced) 11. A bacterial cell has a lactose operon but the promoter is defective (mutated). All else is normal. The bacteria are transformed with a plasmid that contains a wild type (non-mutated) promoter, amp resistance gene, and origin of replication. Can the cell utilize lactose when grown in the presence of the sugar? Why or why not? 12. Match the plasmid feature to the gene _____ allows cell to deactivate ampicillin A. ara C _____ allows plasmid to replicate autonomously B. bla gene (independent of bacterium) C. ori _____ allows cells to manufacture GFP (protein) D. GFP gene _____ regulates the expression of GFP gene E. multiple cloning site _____ enables genes to be ligated into plasmid _____ known as a reporter gene _____ also called ampR _____ recognized by various restriction enzymes _____ a foreign gene not normally found in bacteria _____ enables jellyfish and other marine organisms to glow 13. Why is it useful for a cell to have