Name:_________________________________________________________'!BIOL!360.!Honors!Genetics!Exam!I!September'16,'2010'''Please!put!your!name!on!each!page.''Extra'pages'are'for'work.' Additional'pa per'i s'available'if'nee ded,'but'make'sur e'you'put'your'name'o n'it.''On my honor, I have neither given nor received any unauthorized aid on this exam. Nor am I aware of anyone giving or receiving any unauthorized aid on this exam. _________________________________''' ' signature'and'date'' ' ' ' 'Part'I:'''''' ' /80' 20'fill'ins,'4'pts'each.'Part'II:'' ' /100''''6'word'problems,'20'points'each,'in'order'' ' ' ' ' ' of'approximate'difficulty.' ' ' 'Total:'''''''''''' /200'Name:_________________________________________________________'''Formulas:!Map'Distance,'Linked'Genes:''' (1/ 2) TT[ ]− 2 NPD[ ]( )+ 4 NPD[ ]total number of tetrads× 100''Map'Distance'between'gene'and'centromere:''' (1/ 2) #asci with 2nd div. segregation pattern( )total number of asci× 100'!Part!I.!Fill!in!th e!blank.!3!pts!ea ch.!!1.'______________________________________When'two'unlinked'genes'are'both'completely''' ' ' ' ' linked'to'their'centromeres,'what'portion'of''' ' ' ' ' tetrads'are'expected'to'be'tetratypes?''2.'______________________________________Of'the'four'haploid'gametes'of'meiosis,'the''' ' ' ' ' number'of'recombinant'gametes'if'there'is'one''' ' ' ' ' crossover'in'meiosis''3.'_____________________________________The'value'of'the'chi‐square'test'statistic'in'a'test''' ' ' ' ' of'whether'the'progeny'numbers'55:45'provide''' ' ' ' ' a'satisfactory'fit'to'a'1:1'ratio''4.'______________________________________The'proportion'of'progeny'that'are'ww'when'a''' ' ' ' ' Ww#plant'selfs''4.'______________________________________The'proportion'of'round'pea'progeny'that'are''' ' ' ' ' Ww'when'a'Ww#plant'selfs''5.'______________________________________'If'the'p'value'from'a'Chi‐square'test'is'0.01,''' ' ' ' ' should'you'reject'the'null'hypothesis?'''6.'______________________________________The'class'of'tetrad'produced'when'one'gene'is'' '' ' ' ' ' tightly'linked'to'the'centromere'and'there'is'a''' ' ' ' ' crossover'between'the'centromere'and'the'other'' ' ' ' ' gene.' 'Name:_________________________________________________________''7.'______________________________________Degrees'of'Freedom'in'a'test'for'deviation'from''' ' ' ' ' 15:1''8.'______________________________________Degrees'of'Freedom'in'a'test'for'deviation'from''' ' ' ' ' 9:3:3:1'''9.'_____________________________________The'proportion'of'human'sons'that'are'color''' ' ' ' ' blind'if'the'mother'is'heterozygous'for'an'X''' ' ' ' ' linked'gene'that'causes'color'blindness''10.'____________________________________The'maximum'observable'recombination'''' ' ' ' ' frequency''11.'____________________________________The'number'of'chromatids'per'chromosome''' ' ' ' ' after'during'metaphase'of'Meiosis'II''12.'_____________________________________Genes'A'and'B'are'10'cM'apart.'For'an'individual'' ' ' ' ' that'is'A#B/#a#b,'what'proportion'of'gametes''' ' ' ' ' are'a#B?''13.'_____________________________________In'a'family'of'5'children,'the'probability'that''' ' ' ' ' there'is'not'more'than'1'girl'(unreduced'is'fine)''14.'__________________&_________________Double'Crossover'chromosomes'from'the''' ' ' ' ' genotype'A#B#C/a#b#c.'#'15.'_____________________________________'In'the'case'of'incomplete'dominance,'II#' '' ' ' ' ' snapdragons'have'red'flowers,#Ii#has#pink'''' ' ' ' ' flowers'and'ii#has#white'flowers.'If'plants'with''' ' ' ' ' pink'flowers'are'selfed,'what'is'the'ratio'of''' ' ' ' ' red:pink:white'in'the'progeny?''16.'_____________________________________'Ratio'of'round'to'wrinkled'peas'in'a'Ww#selfing''' ' ' ' ' plant'if'W#egg'gametes'are'inviable'(dead)'''17.'____________________________________The'unreduced'expression'for'the'probability''' ' ' ' ' of'only'1'ww#plant'if'a'Ww'is'selfed'and'has'4''' ' ' ' ' progeny''18.______________________________________'The'distance'between'two'genes'if'only'' '' ' ' ' ' parental'ditypes'are'observed.'''Name:_________________________________________________________'''19.'______________________________________'Mode'of'inheritance'suggested'by'the'following'' ' ' ' ' pedigree'''''''''''''20.'______________________________________'Mode'of'inheritance'suggested'by'the'following'' ' ' ' ' ' pedigree:'''''''!!!!!!!Name:_________________________________________________________'!Part!II.!Word!P roblems.!20!pts!eac h.!1.'In'a'mapping'experiment'using'Neurospora#crassa'heterozygous'for'a'mutation'in'a'gene'required'for'the'production'of'methionine'a'researcher'finds'that'a'certain'number'of'tetrads'do'not'look'like'the'standard'm#m#m#m#+#+#+#+.'Rather,'some'are'out'of'order,'indicating'2nd'division'segregation'that'results'from'a'crossover'between'the'gene'and'the'centromere.'''a.'Draw'a'possible'tetrad'giving'this'conformation:''''''b.'Suppose'out'of'100'tetrads'analyzed,'30'are'tetrads'like'the'kind'above.'What'is'the'distance'in'cM'between'm'and'the'centromere?''''''''2.'After'performing'a'mutant'screen'in'yeast,'three'different'genes'(X,'Y'and'Z)'are'found'necessary'for'the'production'of'the'amino'acid'serine.#Further'characterization'indicates'that'these'genes'are'essential'for'different'stages'of'serine'synthesis.'Strain'x'is'defective'in'producing'precursor'A,'strain'y'is'defective'in'turning'A'into'B'and'z'is'defective'in'turning'B'into'serine'in'the'pathway'below.'''''''Fill'out'the'following'chart'for'whether'growth'would'be'observed'for'strains'x,'y'and'z'under'the'different'conditions.'Indicate'growth'with'a'(+).'''' Complete Media Minimal Media (MM) MM + A MM + B MM+Serine Strain x Strain y Strain z 'B S
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