A Ascospore. B Ascus. C Displacement loop (D-Ioop) D Double-strand break and repair model. E First-division segregation

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1 Test 6 March 6, 2009 Matching 2pts each: Indicate which term/concept in the table on the right best fills in the BLANK in each of the statements by placing the LETTER representing each term/concept in the blank in the sentence. Please note : There is one best tennlconcept for each BLANK.. <2 ro CrA,C 0 1. All four products of meiosis in Neurospora crassa and Saccharomyces cerevisiae are contained in an ---B-. 2. A ~ is predicted to form by the double strand break and repair model but not by the Holiday model. 3. A four-strand double crossover between the genes A and B in yeast results in formation of a /v\. 4. A single crossover between the genes A and B in yeast results in formation of a L. 5. In order to crossisg two yeast strains, they must be ofopposite ~. \\\~ 6..JH. diploid that is formed when two yeast cells mate is called the T. 7. A two strand double crossover between the genes A and B in mold results in formation of a ~. 8. In the double strand break and repair model for recombination, two ~ form. A Ascospore B Ascus C Displacement loop (D-Ioop) D Double-strand break and repair model E First-division segregation F Gene conversion G Heterodup1ex H Holiday [unctions I Holiday junction resolving enzymes J Holiday Models K Mating type L Mismatch repair M lnonparental-ditype (NPD) tetrad N Ordered Tetrads 0 Parental-ditype (PD) tetrad p Random spore analysis Q R S T Second-division segregation Tetratype (TT) tetrad Unordered Tetrad Zygote 9. ~ ofthe heteroduplex fanned by recombination can result in gene conversion. 10. In the Neurospora crassa cross A x a, if one crossover occurs between the gene and the centromere, then you would observe -R- ofa and a. 3

2 Test 6 March 6, You are trying to determine whether there is any evidence for linkage between the Saccharomyces cerevisiae genes, A, B, and C. You perform the cross Abc x abc and analyze 390 asci. The types of asci and the numbers of each type are shown below. Ascus Type Genotypes ofspores in ascus Number of asci 1 abc abc Abc A be 135 'P[) PD PO 2 ab C a b C ABc ABe 124 NPD PD tj PD 3 ab C abc AbC A be 59 PD 1\ -rr 4 ab C abc ABC ABe 70 ",IPD 'T'\ 11"" 5 abc abc AbC AbC 1 'PD N i'.d N Pj) 6 abc abc ABC ABC 1 tjpo I-J PD PD From these results, determine the following (3.3 points each): a) Are A and B linked? If so, what is the map distance between A and B? b) Are A and C linked? Ifso, what is the map distance between A and C? c) Are B and C linked? If so, what is the map distance between B and C? b. ~ ~) A b 'J ~ ~ ~ rd ~ N r D ~ tw f ~ ;JSI L\,V Itk{) '[z. En],j 1 em PQ].J. 'p TAL 18.c1 flj~ 0 eo : ' S6 ' N (1 I) :" I L ) I f 'f) ~ N I' I) - B T C,IVu'l L //VlifU) r }F- e()i~. 12 L t c::. I \N lajjvu2 c: (/0 IN'\) 0 [p- CcYZ!UZ.C-1 r. f 0 'IV\) ~ \~ L f/vltr-o ~\ C - S ") fa} "r n --.t)(i fd rl b) fo lj../o IF N vvl- rh {j v J P- v. G J ~v"\ If

3 \ f -ro. of-.\(... \ 1'.) c) (W~ /L- \ lj Test 6 S\WAJ v. ",-, "-- March 6, 2009 Chl C('JLQ l \ 12. The following classes and frequencies of asci were o~the cross A b x a B in Neurospora crassa, A and B are on the same chromosome, Genotype ofspore Pairs Ascus Type Number of Asci Ab Ab ab ab /$t'" 80 P.P 1 ~ 2 Ab ab AB I ab I '2.1'-S,. 10 TI,:v:.! 3 Ab as ab.,.--, l ~ 10 'Z'~ AB I~ - C::fN Use these results to draw a map showing the locatlons ofa, B and the centromere showing the genetic distance between each location ?: LI N)(A (;C O r-l-ar W~ o <t,1(' <~~ ~lrl L lit] C ~. ~ 01; ' ftla L PD \ ( ((2.,. (z.:- )-+ D )( I 5. ; ()AJl '-( I Q / 1o o --Z ":!. A- ~ b'j ~ \ 'D IJ 'IAA G.A 'IV MAP JI'J I'D " 'Pl Vi "s I <.v,,) J' Q 6rv - (; A fl oj--.' ) '( 1... (Jt 2C O\ J, J 1L 6) --rotp'";4'l " l00 I{ L ( (0) / u"\) -z» (L (]U) ': --~. f.. l O U I J ' ) r \ -~~ ~- A l...! D l \ b- (V\LA -/<- f (VI \.< -.;J -... z \ 0 fv\~ - ( rc~ 7

4 Test 6 March 6, (10 Points) The drawing for this question shows two yeast non-sister chromatids. The top drawing is before any -'crossovers occur. The bottom drawing is based on the Holiday model for recombination and shows the chromatids joined by a crossover. The other two non-sister chromatids of these chromosomes are not shown, The top chromatid (black and blue) has the A, B, and D alleles. The bottom chromatid (red and green) has the a, b, and d alleles. The cross, A B D x a b d was done. Among 200 asci, one unusual ascus was found. The spores in this ascus had the following genotypes: A B D; A b d; a b D; a b d I (?f"~ CZA-Ci.4-.. ().JL "t:rvlc) ~~ " fc Use this information to do the following (2 points each): A Iu.)V\j a) YVha~}-ahrnIrtlreaseli~..whatisJ:he te ~ ::t.. ijdescribe-fu~nlt~ c cuited to generate this ascus? :3 ~ I S"G:Grt ballon OF b -+ B ;- cg~/vre. co~ b) label the 5' and 'ends of every strand of DNA sho~ ii-ltre-dtawmg. c) Indicate the location of the A, a, B, b, D and d alleles in the top drawing. d) Indicate the location of the A, a, D and d alleles in the bottom drawing. e) Indicate how the Holiday junction was cut to resolve the chromatids in a manner that is consistent with the genotype of the spores in the ascus. Show the location of the cutsvcnorth south or east west is not sufficient). ~\ l :5,4,-/l iv re, \ r l s P\>ft. 'f\.) (l f 4IL~ 6'f- f= (6 L/!L1t ( '~'L «"0{\\lM. f' AttT.. ~ g ~ CQ (lju2 C-1 1 A LL WVOJ (~ c) A Dv\. CJ~ J f L\.l Cu~fkv-) f;:).o 11 ~ o -e-h.i...--'-- I ~ IN rtl-v_ JY1 i lcue ' CAPs OA -1-Dp 1 ' C)~ C tz '} ~ \ c V\!\"N. {" Q tb (.,V\. ~ 2 en Of?.. ~t.u \.... '-I { GJT fvrz ca ~ A "CA./ ~ Or l:::j0o,--- '-. I ' c\ \ 1 ~/l... ( o-v-v (OW-V- Cc-.Yl C C/}( 6 ct:;j D-I -'2 <JO J'k (<-..J C v c\ o,-, ~ r rf- ~ ~ tg.iv\ \ Z- -.;) r bfvz r..j

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