B250WT3F04 - M .CO 411 MED - PR E BIL 250/GU “Genetics”...

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Unformatted text preview: M .CO 411 MED - PR E BIL 250/GU “Genetics” 11/23/04 Form 1 D41 1.C OM Exam 3 UM Student ID#: P - PR EME Name: - PR EME D41 1.C OM - PR EME D41 1.C OM 1. Mark down your name, student ID, form number, and your seat number on the scantron (Answer sheet). 2. Write down your name and your student ID on the short answer question page now! 3. When you finish, please return your exam question sheet, your answer sheet (scantron) and your answers to the short answer questions. 4. Please silence your cell phones during exam! D41 1.C OM Multiple choice format (select the most appropriate choice to answer each question. Each question is worth 1 point) - PR EME D41 1.C OM - PR EME 1. For linked genes A, B, and C, if the A-B map distance is 1.56 map units and the B-C map distance is 4.06 map units and the number of double crossover events out of 10,000 offspring is 6, what is the coefficient of coincidence? Is the interference between the two crossover events a positive or negative? OM - PR EME D41 1.C OM a. 0.15, negative b. 0.48, positive c. 0.57, no interference d. 0.89, negative e. 0.95, positive - PR EME D41 1.C 2. If you have three genes (A, B, and C) linked on the same chromosome, how can you determine the gene order? - PR EME D4 11. COM - PR EME D41 1.C OM a. Look for double crossover phenotypes involving the wild type and mutant alleles of genes A, B, and C. b. Look for single crossover phenotypes involving the wild type and mutant alleles of genes A, B, and C. c. Look for parental phenotypes. d.You cannot determine gene order by looking at the results of a cross. 3. Complete linkage results in the production of only __. ED4 11. COM - PR EME D4 11. COM a. crossover gametes b. recombinant gametes c. female gametes d. male gametes e. parental gametes PRE MED 411 .CO MPRE M 4. For 3 linked genes, the fraction of single crossovers between genes 1 and 2 and genes 2 and 3 are both 0.11 and the double crossover fraction is 0.0121. M .CO 411 MED - PR E D41 1.C OM Which of the following is true? - PR EME D41 1.C OM - PR EME a. There is evidence of substantial negative interference. b. There is evidence of substantial positive interference. c. The distance between 2 and 3 is larger than that between 1 and 2. d. The distances between 1 and 2 and 2 and 3 are comparable. e. The distance between 1 and 2 is larger than that between 2 and 3. - PR EME D41 1.C OM 5. Phenotypically wild F1 female Drosophila, whose mothers had light eyes (lt) and fathers had straw (stw) bristles produced the following offspring when crossed to homozygous light-straw males: PHENOTYPE NUMBER OM - PR EME D41 1.C OM 22 18 990 970 2,000 D41 1.C light-straw wild light straw Total - PR EME D41 1.C OM 4 6 8 2 10 1.C OM a. b. c. d. e. - PR EME The map distance between the light and straw loci is: - PR EME D41 6. Chromosomal aberrations may be characterized by all of the following except __________. 11. COM - PR EME D41 1.C OM a. chromosome loss b. chromosome duplication c. translocations d. inversions e. frameshift mutations 11. COM - PR EME D4 7. While the most frequent forms of Down syndrome are caused by a random error, nondisjunction of chromosome #21, Down syndrome occasionally runs in families. The cause of this form of familial Down syndrome is ________. PRE MED 411 .CO MPRE M ED4 11. COM - PR EME D4 a) an inversion involving chromosome #21 b) a translocation between chromosome #21 and a member of the A chromosome group c) a translocation between chromosome #21 and a member of the B chromosome group d) a translocation between chromosome #21 and a member of the C chromosome group M .CO 411 MED - PR E - PR EME D41 1.C OM e) a translocation between chromosome #21 and a member of the D chromosome group The maternal effect in Limnaea is such that the genotype of the egg determines the direction of shell coiling regardles of the genotype of the offspring. Apparently the cause of this spectacular maternal effect results from - PR EME D41 1.C OM 8. genophores present in the egg cytoplasm. orientation of the spindle apparatus in early cleavage. the F factor exerting its influence on the centrosome. colicins "poisoning" one of the cleavage centers. allelic substitution as demonstrated from RNA injection experiments. - PR EME D41 1.C OM a). b). c). d). e) - PR EME D41 1.C OM 9. Recombination in bacteria differs from recombination in eukaryotes in which of the following ways? D41 1.C OM - PR EME D41 1.C OM a). A portion of DNA from one genome is replaced with DNA from another strain of bacteria. b). Only the plasmid DNA goes through recombination in prokaryotes. c). Recombination does not occur in prokaryotes. d). Sister chromatids, instead of homologous chromosomes, exchange information during recombination. - PR EME 10. Which of the following strains is a prototroph? 1.C OM - PR EME D41 1.C OM a). thr+ leu- met+ b). thr- leu+ metc). thr- leu+ met+ d). thr+ leu+ met+ e). None of the above - PR EME D41 11. Hfr strains result from integration of ___. - PR EME D4 11. COM - PR EME D4 11. COM a). a chromosomal DNA into a bacterium b). the integration of the F factor into the bacterial chromosome of an F+ strain c). the integration of the F factor into a phage d). the integration of the F factor into a bacterium e). the integration of the F factor into the bacterial chromosome of an Fstrain PRE MED 411 .CO MPRE M ED4 11. COM 12. A virus that can reproduce by either the lytic cycle or the lysogenic cycle is called ___. a). A virulent phage b). A temperate phage M .CO 411 MED - PR E - PR EME D41 1.C OM c). A lysogenic phage d). A nonvirulent phage e). None of the above 1.C OM - PR EME D41 1.C OM 13. The restriction enzyme DdeI recognizes a DNA sequence, CTNAG (where N is any base) and cuts the sequence at that point. A portion of the ßhemoglobin sequence encoding normal hemoglobin is CTGAGGAG. The allele responsible for sickle cell anemia is CTGTGGAG. Which allele will the restriction enzyme DdeI recognize and cut? - PR EME D41 1.C OM - PR EME D41 a. Normal beta chain allele b. Sickle beta chain allele c. Both normal and beta alleles d. Neither normal nor sickle alleles will be cut. D41 1.C OM - PR EME D41 1.C OM 14. Recombinant DNA research is dependent on __________. a. cloning b. hosts c. vectors d. restriction endonucleases e. All of the above are correct. OM - PR EME 15. Restriction enzymes that produce staggered cuts known as “sticky ends” are useful because: - PR EME D41 1.C OM - PR EME D41 1.C a. sticky ends stick to almost anything b. DNA fragments cut with the same enzyme can anneal to each other c. blunt cuts are never desirable in DNA engineering d. staggered cuts won’t join with other DNA fragments regardless of how they were cut e. sticky ends allow fragment ends to reanneal, which is usually desirable - PR EME D4 11. COM 16. A library representing the genes active in a specific cell type at a specific time (genes being expressed) is called a: - PR EME D4 11. COM a. chromosome-specific library b. genomic library c. cDNA library d. phage library e. transposon library PRE MED 411 .CO MPRE M ED4 11. COM 17. Compared with prokaryotic chromosomes, eukaryotic chromosomes are a). large, mainly organized in monocistronic transcription units without introns. M .CO 411 MED - PR E small, mainly organized in monocistronic transcription units with introns. large, mainly organized in polycistronic transcription units without introns. small, mainly organized in polycistronic transcription units without introns. large, linear, less densely packed with protein-coding genes, mainly organized in monocistronic units with introns. - PR EME D41 1.C OM b). c). OM d). - PR EME D41 1.C e). D41 1.C OM - PR EME D41 1.C OM 18. You have made a mouse DNA library by cloning mouse DNA fragments into the circular vector pBR322 at the BamHI (DNA restriction enzyme) site and then transforming the plasmid into E. coli. You select one bacterial colony (derived from a single individual) and extract plasmid DNA. You digest the plasmid DNA with BamHI. You get a single 4.36 kb fragment (pBR322 is 4.36 kb in size). Does this plasmid contain a cloned gene? 1.C OM - PR EME a). Yes b). No OM - PR EME D41 19. Under strictly-controlled conditions, a probe can be used which will hybridize only with its complementary sequence and not with other sequences that may vary by as little as one nucleotide. What are such probes called? mutation-specific probes short, variable repeats VNTRs allele-specific oligonucleotides (ASOs) microsatellites - PR EME D41 1.C OM - PR EME D41 1.C a). b). c). d). e). 1.C OM 20. If a normal (wild type) repressor is added in vitro, which DNA fails to bind the repressor? - PR EME D4 11. COM - PR EME D41 a). I+ O+ Z+ b). I+ Oc Z+ c). I- O+ Z+ d). I+ O+ Ze). All of the above will bind the repressor. COM 21. A mutation in the I gene of the lac operon directly affects __________. MPRE M ED4 11. COM - PR EME D4 11. a). B-galactosidase b). the repressor c). the promoter d). permease e). the operator region PRE MED 411 .CO 22. What would be the effect of a mutation in the operator that blocked the lac M .CO 411 MED - PR E D41 1.C OM repressor binding? - PR EME D41 1.C OM - PR EME a). The lacZYA genes would not be expressed. b). The lacZYA genes would be repressed by lactose. c). The genes would be inducible by lactose. d). The lacZYA genes would be expressed constitutively. e). None of the above. 1.C OM 23. Genes that are always transcribed are called: - PR EME D41 1.C OM - PR EME D41 a). transposons. b). operator genes. c). constitutive genes. d). operons. e). repressor genes. 1.C OM 24. Enhancer elements are found ___. - PR EME D41 1.C OM - PR EME D41 a). within the gene sequence b). downstream from the start site of the gene sequence c). upstream from the start site of the gene sequence d). in any of the above regions e). in none of the above regions; enhancers are environmental agents OM 25. Which of the following sequences contains a eukaryotic promoter? D41 1.C OM - PR EME D41 1.C a). GTCCTATATAAATGGGC b). GCATCCCGGTACGCGAC c). CGAGAGATTTTGCCGCA d). CATAGATACCCGGGACC e). None of the above sequences contain a eukaryotic promoter. 11. COM - PR EME 26. Regarding enhancers and transcription factors (TFs) and their effect on gene expression, ___. - PR EME D4 11. COM - PR EME D4 a). enhancers are trans-activating, while TFs are cis-activating b). neither are cis nor trans-activating; they are repressors c). enhancers are cis-activating, while TFs are trans-activating d). both are cis-activating e). both are trans-activating PRE MED 411 .CO MPRE M ED4 11. COM 27. In the absence of tryptophan: a). The repressor is active and does not bind to the promoter. Transcription does not occur. b). The repressor is inactive and does not bind to the promoter. M .CO 411 MED - PR E - PR EME D41 1.C OM Transcription is initiated. c). The repressor binds to the co-repressor. Transcription is initiated. d). The trp operon is repressed and transcription occurs. - PR EME D41 1.C OM 28. What is the term which refers to the regulatory events which establish a specific pattern of gene activity and developmental fate for a given cell? - PR EME D41 1.C OM a) lysogen b) differentiation c) determination d) gradient regulated e) attenuation - PR EME D41 1.C OM 29. __________ and __________ are two classes of proteins known to regulate the cell cycle checkpoints. OM - PR EME D41 1.C OM a). Protein kinases/cyclins b). Cyclin-dependent kinases/cyclins c). p53/polymerases d). Ligase/polymerases e). Protein kinases/ATP synthase - PR EME D41 1.C 30. Why is familial retinoblastoma known to be inherited as an autosomal dominant trait when the responsible gene is recessive? - PR EME D41 1.C OM - PR EME D41 1.C OM a). This recessive gene needs only one copy to express this phenotype. b). People with this mutation are always homozygous for this allele when they were born. c). If you are born with one allele mutated in every cell, the chance that the other allele will be mutated in one of the retinal cells is extremely high. d). Retinoblastoma was mischaracterized originally when it was called an autosomal dominant trait. 11. COM Extra credit question: - PR EME D4 31. Which of the following are examples of cis acting genes? COM - PR EME D4 11. COM a. lacI, lacZ b. lacI, lacY, lacZ c. lacP, lacO d. lacY, lacZ, lacA e. lacI PRE MED 411 .CO MPRE M ED4 11. 32. A news article published in “Nature” on 10 November 2004 reported a new way to lower cholesterol using RNA Interference technique. In the past, scientists often had difficulties to deliver the treatment to the right part of the patient’s body. According to M .CO 411 MED - PR E - PR EME D41 1.C OM this report, researchers from Germany and the U.S. have figured out a way to solve the problem, at least for treating high cholesterol. They modified the RNA molecule used to trigger the interference by attaching a cholesterol molecule to it. This is because: - PR EME D41 1.C OM a) Cells that make cholesterol have no cholesterol antibodies on their surface, so that the modified RNA complex can be taken up by these particular cells in the right body part. 1.C OM b) Cells that make cholesterol have no cholesterol receptors on their surface, so that the modified RNA complex can be taken up by these particular cells in the right body part. 1.C OM - PR EME D41 c) Cells that make cholesterol have cholesterol receptors on their surface, so that the modified RNA complex can be taken up by these particular cells in the right body part. - PR EME D41 d) Cells that make cholesterol have cholesterol antibodies on their surface, so that the modified RNA complex can be rejected by these particular cells in the right body part. PRE MED 411 .CO MPRE M ED4 11. COM - PR EME D4 11. COM - PR EME D4 11. COM - PR EME D41 1.C OM - PR EME D41 1.C OM - PR EME D41 1.C OM - PR EME D41 1.C OM e) None of the above is correct. ...
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This document was uploaded on 10/27/2011 for the course BIL 250 at University of Miami.

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