Unformatted text preview: York BIOL 2040 Fall 2009 Kelly Midterm 2B Nov Biology 2040 Midterm II Version B Nov. 13, 2009 / 8:30 – 9:15 am • This test consists of 24 questions (including a version indicator). There are 6 pages. • This test is 45 minutes long • This entire exam booklet must be submitted with your scantron sheet to receive a grade. • Your student number and name must be CLEARLY written on this booklet and scantron sheet in order to receive a grade. • Your student number must be BUBBLED CORRECTLY on the scantron to receive a grade. Please check your student number bubbling! • Please answer all questions on the scantron. • Choose the single best answer out of the options for each question. Read each question (and all possible answers) carefully. • All questions on this exam are multiple choice – there is NO pattern to the answers (e.g., c, a, b, b, a, d), so don’t look for one! • Non‐programmable calculators are allowed. Cell phones, mp3 players and other electronic devices are NOT allowed and must be turned off and put away. • If you complete the exam before the allotted time, raise your hand to identify yourself to the invigilator. • Invigilators reserve the right to move students during the test. This may not reflect suspicion of you (e.g., someone behind you may be looking at your paper). However, please not that aiding & abetting any cheating is an academic honesty offense in itself. • If you finish the exam in the last 10 minutes of the test time, you must remain at your seat until the exam is over & your test has been picked up. Good Luck! First Name Last name Student Number 1 York BIOL 2040 Fall 2009 Kelly Midterm 2B Nov 1. You have exam version B, which must be indicated on the scantron to get credit for your test questions. A. No X B. Pick me!!!! C. No X D. No X E. No X 2. New combinations of alleles are a direct benefit of recombination. A. True B. False 3. Genes K and M are 10 m.u. apart. The progeny of the cross KKmm x kkmm are mated to each other. What is the probability that the F2 will be km in phenotype? A. 8% B. 16.5% C. 20.25% D. 45% E. 90% 4. Suppose the J and T genes are on the same chromosome, but are separated by 100 map units. What fraction of the progeny from the cross JT/jt x jt/jt will be Jt/jt? A. 10% B. 25% C. 50% D. 70% E. 100% 5. In Drosophila, singed bristles (sn) and vestigial wings (vg) are both caused by recessive, X‐linked alleles. The wild‐type alleles (sn+ and vg+) are responsible for straight bristles and normal sized wings, respectively. A female homozygous for sn+ and vg is crossed to a sn vg+ male. The F1 flies are interbred. The F2 males are distributed as follows. Given these results, what is the map distance between sn and vg A. 9.8 m.u. sn vg 82 B. 8.2 m.u. sn vg+ 393 C. 18 m.u. sn+ vg 427 D. 25 m.u. sn+ vg+ 98 E. 50 m.u. 2 York BIOL 2040 Fall 2009 Kelly Midterm 2B Nov 6. A researcher is interested in whether eye colour gene is linked to an RFLP marker that had been previously identified. A cross is made between two inbred lines. Parent 1 is homozygous for the recessive white eye colour, and has the RFLP banding pattern given below. Parent 2 is homozygous for the red eye colour and shows the RFLP banding pattern shown. The F1 individuals are crossed with each other. If the eye colour gene is 20 m.u. from the RFLP marker, what proportion of the F2 will have the gel pattern shown below AND have white eyes? P1 P2 A. 40% White Red F1 Red White B. 20% C. 1% D. 2% E. None of A‐D 7. The chi‐square test measures ‘goodness of fit’ between observed and predicted results. A. True B. False 8. For an individual with met+ arg+ / met arg, the genes are in trans conformation. A. True B. False 9. Three genes, v, ct, and cv are linked. The genetic map is shown below. A cross is performed between a wild type female who is homozygous and a homozygous mutant male. When the F1 is testcrossed 1448 offspring are produced, 8 of which are double recombinants. What is the amount of interference in this region? A. 35% 13.2 m.u. 6.4 m.u. B. 55% v-----------------ct---------------cv C. 65% D. 85% E. 50% X 10. A study claims that two genes are 64 m.u. away from each other on chromosome 3 of a species of hamster. Which of the following is true about this claim? A. It is impossible. B. It is only possible if negative interference is happening. C. It is only possible if additional markers were used to construct the map. D. It is only possible if there is a chromosomal mutation. 3 York BIOL 2040 Fall 2009 Kelly Midterm 2B Nov 11. In humans, the genes for red‐green colour blindness (R = normal, r = colour‐blind) & hemophilia A (H = normal, h = hemophilia) are both X‐linked and only 3 m.u. apart. A normal man & a woman whose mother is colourblind (& isn’t a carrier for hemophilia) and whose father has hemophilia A, is pregnant with a boy and wants to know the probability that he will have normal vision and normal blood clotting. What is the probability? A. 0.47 B. 0.015 C. 0.485 D. 0.03 E. 0.15 12. A wild‐type yeast strain is crossed with another strain that requires both arginine and uracil added to the medium to grow. The resulting cells undergo meiosis and the products of meiosis are analysed. There are three classes of unordered tetrads observed; the results are summarized below. What is the map distance between the arg and uracil genes? Class 1 (250 tetrads): Class 2 (10 tetrads) Class 3 (140 tetrads) 2 spores grow on arg & uracil 2 spores grow on arg 1 wild‐type spore 2 wild‐type spores 2 spores grow on uracil 1 spore grows on arg & uracil 1 spore grows on arg 1 spore grow on uracil A. 20 m.u. B. 40 m.u. C. 36 m.u. D. 2 m.u. E. The genes are unlinked. 13. Which of the following is true of plasmids? A. They are composed of RNA. B. They normally exist outside of bacterial cells. C. They possess only a single strand of DNA. D. They replicate independently of the bacterial chromosome. 14. If an Hfr cell is allowed to carry out conjugation with a recipient E. coli cell, but is interrupted after 5 minutes, the resulting cells will be (donor, recipient) A. Hfr, Hfr B. Hfr, F+ C. Hfr, F‐ D. F‐, F‐ E. F+, F‐ 4 York BIOL 2040 Fall 2009 Kelly Midterm 2B Nov 15. Which of the following is a mutant that has a nutritional requirement for growth? A. A morphotroph B. An autotroph C. A nutrotroph D. An auxotroph E. A heterotroph 16. DNA is transferred from a dead bacterial donor to a living bacterial recipient cell through: A. Conjugation B. Transformation C. Transduction D. All of A to C E. Only 2 of A to C. 17. During transfer of DNA via conjugation, DNA replication A. Does not occur in either cell (neither the donor nor the recipient). B. Occurs in the recipient. C. Occurs in the donor. D. Both B and C. 18. F+ strains of E. coli A. Do not possess an F factor. B. Have the F factor as a plasmid. C. Have an F factor integrated into the chromosome. D. Can transfer genes to F+ cells. 19. A cell with nonidentical mitochondrial genomes is said to be A. Homoplasmic B. Heteroplasmic C. Uniparental D. Biparental 20. Several characteristics of mtDNA make it well suited to the study of evolutionary relationships. Which of the following is not one of these characteristics? A. mtDNA is typically inherited from only one parent and thus, mtDNA genes are not altered by recombination every generation. B. mtDNA tends to mutate at a higher rate than nuclear DNA, so mtDNA can be used to study relationships of closely related organisms. C. mtDNA is shorter than nuclear DNA making mtDNA easier to analyze. D. mtDNA is heteroplasmic allowing the study of several lineages at once. E. None of the above (A to D). (All of the above answers are useful characteristics to evolutionary studies.) 21. For a mitochondrial disease, an affected man would pass on the disease to half of his children. A. True B. False 5 York BIOL 2040 Fall 2009 Kelly Midterm 2B Nov 22. Knudson’s 2‐hit hypothesis explains why someone born with a mutation in a tumour suppressor gene might develop cancerous tissue at a much earlier age, than someone born with 2 normal copies of the same gene. A. True B. False 23. An F1 individual heterozygous for 3 genes, RrSsTt, is testcrossed. The most abundant classes are S rrSsTt & Rrsstt, while the rarest classes are RrSstt & rrssTt. Which gene is in the middle? _____ 24. (5 marks) A met+ arg haploid strain of Neurospora is crossed with a met arg+ haploid strain. A total of 1000 ordered tetrads are isolated and categorized as follows: I II III IV V VI VII + + + + + + + + + met arg met arg met arg met arg met arg met arg met+ arg+ met+ arg met+ arg+ met+ arg+ met+ arg met+ arg met+ arg+ met+ arg+ met+ arg met+ arg+ met+ arg met arg met arg+ met arg met arg + + + + + met arg met arg met arg met arg met arg met arg met arg met arg+ met arg met arg+ met+ arg+ met+ arg met+ arg+ met+ arg met arg+ met arg met arg+ met+ arg+ met+ arg met+ arg+ met+ arg + + + met arg met arg met arg met arg met arg met arg met arg+ met arg+ met arg met arg met arg+ met arg+ met arg met arg+ 800 1 95 4 94 1 5 a) Are the genes met and arg linked? Yes / No (Circle choice) 5.2 m.u. b) What is the distance of gene met to its centromere? _______________ 9.75 m.u. c) What is the distance of gene arg to its centromere? _______________ accepted either 5.4 d) What is the distance between genes met and arg? __________________ m.u OR 4.55 m.u (2nd answer is corrected distance) e) Are the two genes on the same side of the centromere? Yes / No (Circle choice) END OF TEST 6 ...
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