Zoo/Bot 3333 Genetics Quiz 4 November 20, 2006 For answers to the quiz click here: 1. Arabidopsis thaliana has among the smallest genomes in higher plants, with a haploid genome size of about 100 Mbp. Assuming B form DNA, in a single somatic cell, if the DNA from all of the chromosomes was laid end-to-end, it would stretch: a) 0.3 mm; b) 6.8 cm; c) 3 meters; d) 6 kilometers; e) from New York City to Hartford, Connecticut. 2. A kan r tet r plasmid is treated with the restriction enzyme BglI, which cleaves inside the tetracycline (tet) gene. The DNA is annealed with and ligated to a BglI digest of Neurospora DNA and then used to transform E. coli. Which phenotype is expected to contain Neurospora DNA inserts? a) kan r tet r; b) kan s tet s; c) kan r tet s; d) kan s tet r; e) tet s either kan sor kan r. 3. The accompanying table shows the presence or absence of seven sequence-tagged sites (STS’s) numbered 1-7, in each of six BAC clones, designated A-F. A “+” in the table means that PCR primers specific to the STS are able to amplify the sequence from the clone, a “-“ means that the sequence can not be amplified from the clone. BAC Clone A B C D E F 1 + + - 2 + + 3 + - STS marker 4 5 + + + + 6 + + - 7 + - The relative order of the STS sites within the cloned genome can be ordered as: a) 3427165; b) 1527634; c) 3514276; d) 7251643; e) 2541673 Gene Q Gene R Gene S Gene T Questions 4-5 pertain to the following ASO Q1 Q2 R1 R2 S1 S2 T1 T2 experiment. Four pairs of PCR primers Somatic Cell were used to amplify DNA isolated from Sperm number one man's somatic cells, and from 20 1 single sperm that he donated for this 2 3 study. Each primer pair amplifies a 4 different region of the human genome, 5 referred to as genes Q, R, S and T. Each 6 of these amplified regions was then 7 divided into 8 aliquots (i.e. 8 identical 8 subsamples) and these 8 DNA samples 9 were denatured and spotted onto 10 11 membrane strips for nucleic acid 12 hybridization analysis, as shown in the 13 figure at the right. The membranes were 14 hybridized to 8 different oligonucleotide 15 probes, which are designed to distinguish 16 single-nucleotide base differences in the 17 18 DNA. The paired oligonucleotides 19 Q1/Q2, R1/R2, S1/S2 and T1/T2 are 20 therefore regarded as allele-specific oligonucleotide probes (ASOs). A black circle on the diagram indicates that the amplified DNA hybridized to the indicated ASO probe (e.g. binding of the radiolabeled oligonucleotide to the amplified DNA, as detected by autoradiography). 4. Based on the results shown, which gene(s) could be X-linked? a) Q; b) R; c) S; d) T; e) more than one of the above. 5. Which gene(s) must be autosomal and homozygous for a particular ASO? a) Q; b) R; c) S; d) T; e) more than one of the above. Regan's DNA Butch Coolridge’s DNA Tony Contralto' s DNA victim's DNA 6. On the basis of the above data, what is the map distance between the two genes that are linked to one another? a) 5 map units; b) 10 map units; c) 15 map units; d) 20 map units; e) 25 map units. Glass #2 Glass #1 cigarette victim's fingernails Questions 7-8 pertain to the following: Lt. Sandy Hippowits of the 32rd precinct has a crime to solve. The female victim, stabbed with a kitchen knife, lies on the sofa in an apartment, which she shares with her sister, Regan. There are two empty glasses on the coffee table, a half-eaten birthday cake, and a cigarette in the ashtray. Both of the glasses have lipstick on them, but not the cigarette. The victim's purse also lies open on the coffee table; it contains her keys and lipstick, but no wallet or credit cards. It also contains a matchbook for the Dadading Club with a phone number written on the interior of the matchbook. The phone number leads to Tony Contralto, owner of the Dadading club. A credit card belonging to the deceased turns up in the hands of Butch Coolridge, an itinerant ex-boxer who says he got it out of the Dumpster at the Dadading club. The victim’s wallet was in the dumpster, wiped clean of prints. Interviews with neighbors indicate that a major quarrel was heard the night of the murder, with someone heard screaming "it’s my party and I'll cry if I want to". All suspects deny being present at the time of the murder. Forensic analysis of the crime scene indicated that the victims' fingerprints were on one of the glasses, while her sister Regan's fingerprints were on the other glass. The lipstick on the victim's glass appeared to come from the lipstick in the purse. DNA from cells located on both glasses and the cigarette could also be recovered. In addition, there was skin under the fingernails of the victim, which could also be typed using minisatellite markers. These samples were compared with the DNA of the principal suspects with the results shown. 7. Which of the following is the likely murderer? a) Regan, b) Tony Contralto; c) Butch Coolridge; d) evidence implicates them all; e) evidence suggests another potential suspect. 8. Whose birthday was it? a) the victim’s; b) Tony Contralto; c) Butch Coolridge; d) Regan; e) two of the above are correct. Questions 9 and 10 pertain to the following. Six independently derived mutants are recovered in Neurospora that are all able to grow on compound Z. The mutants are then grown on minimal media supplemented with one of 6 chemicals all known to be precursors to compound Z. A summary of the ability of the mutants to grow on media containing these chemicals is indicated below, where a “+” sign indicates growth and a “-” sign indicates no growth. Mutant number 1 2 3 4 5 6 A B Chemical Compounds C D E F Z + + + + + + + + + + + + + + + + + + + + + 9. The immediate precursor to compound Z (i.e. next to last compound in pathway) is: a) E; b) C; c) F; d) A; e) none of the above. 10. A mutation in gene 2 should lead to an accumulation in which metabolite in the pathway? a) E; b) C; c) D; d) A; e) none of the above.