Download GENETICS 310 Exam 1, Sept.25, 2012 NAME 1a) When a male

 GENETICS 310 Exam 1, Sept.25, 2012 NAME 1a) When a male from a true breeding black colony of Labrador retrievers is crossed to female from a true breeding yellow colony, all the pups are yellow. Sib matings between F1 males and females show a single gene phenotypic ratio. Y_ Yellow Make a legend that explains coat color as seen so far: yy black Use your legend to predict the genotypes of the: male parent yy female parent YY F1 pups Yy F2 phenotypic ratio 3 Yellow: 1 black F2 genotypic ratio 1YY:2Yy:1yy 1b) When the same male is crossed to a true breeding chocolate (brown) female, all the progeny are black, and again a single gene ratio is found in the F2 Make a legend that explains coat color as seen in this cross: Bl_ black Bl/bl chocolate Use your legend to predict the genotypes of the: male parent Bl/Bl female parent bl/bl F1 pups Bl/bl F2 phenotypic ratio 3 Black : 1 chocolate F2 genotypic ratio 1Bl/Bl : 2 Bl/bl: 1 bl/bl 1c) When a truebreeding chocolate is mated to a true CY_ yellow breeding yellow, all the pups are yellow. Make a CB_ black new legend assuming coat color in labs is a single cc/cc chocolate gene trait with multiple alleles. (In order of dominance) Use this legend to predict the genotype of the F1 pups from each of the matings: 1a) CYCB 1b) CB/cc 1c) CY/cc 1d) Predict the phenotypic ratio if a 1a pup in the previous answer is crossed to a 1c. 3 yellow : 1 black 1e) Now suppose the inheritance follows the legend: B_, C_ , black Predict the ratio from the cross Bb, cc X Bb, Cc. B_, cc chocolate (3B_ : 1 bb)(1Cc : 1cc) gives 3B_,Cc: 3B_ cc : 1bb,Cc : 1bb, cc) bb, C_ yellow bb, cc yellow. 3 Black: 3 chocolate:2 yellow (Cross was intended to be Bb, Cc X Bb, Cc) 2. Place the letter of each example in the blank for the appropriate term or terms EXAMPLE TERM A. Drosophila larvae developing in the presence of griseofulvin emerge without eyes, as do mutants D,E pleiotropy homozygous for ey/ey B. Beagles with the SP allele at the spotting locus can have one large to many small black patches, or rarely no spots at all. epistsis C. A number of different gene defects have been shown to lead to failure in angiogenesis (growth of new blood vessels) in mice, some of which prevent embryos from developing but C genetic others only causing effects in adults heterogeneity D. Defects in the ACP5 gene in humans lead to abnormal vertebrae, immune dysfunction and neurological problems A teratogen that cause spastic movements. E. Maize plants that are lx8/lx8 are unusual in that they have empty shoots at every node, tassels with no pollen but with B variable ears, green rather than purple taproots, and stiff stalks. expressivity A phenocopy C age of onset B lack of penetrance III. a) Check the following ratios that are an indication of epistasis: X 9 round : 3 long: 4 oval 3 resistant : 1 susceptible X 15 green : 1 yellow 8 creeper : 4 normal X 9 color: 7 albino X 13 Tall : 3 dwarf b) Fill in the ‘cells’ below to show labeled chromosomes in early anaphase of Mitosis and Meiosis I The individual is heterozygous for genes G and H that are on different chromosomes Meiosis I Mitosis IV. Legends for traits in a flower (elephant ear is the common name) are shown below. S_ leaf spots G_ green veins LhLh heart shaped leaf XaLXaL lethal embryo h
l
ss no leaf spots gg white veins L L wide leaf XaLXa, leaf-­‐1 yellow Ll Ll lance leaf XaXa leaf-­‐1 green A_ Give the phenotype of plant-­‐1 that is heterozygous for each gene. Leaf spots, green veins wide leaf, leaf-­‐1 yellow B. Plant-­‐2 has leaf spots, white veins, wide leaves and its first is leaf yellow. When crossed to plant-­‐
1, progeny of each viable phenotype are recovered, Give the genotype of plant-­‐2. Ss, gg, Lh/Ll, XaL/Xa C. How many different kinds of gametes can each plant produce? 1) 2X2X2X2 2) 2X1X2X2 D. What fraction of the seeds from the cross in part B would grow into plants that have no leaf spots, green veins, wide leaves with leaf 1 green? ¼ X ½ X ½ X 1/3 (1/4 for last trait OK if assume seeds without embryos are planted) E. What fraction of the viable seeds from the cross would have the genotype Ss, gg, LhLl, XaLXa? ½ X ½ X ½ X 2/3 F. Two plants heterozygous for green veins are crossed. If 10 seeds are produced and grown, what is the probability that 7 of the plants will have: 1) green veins? 10!/7!3! X (3/4)7(1/4)3 2) that 4 will be GG, 4 Gg and 2 gg 10!/4!4!2! X (1/4)4(1/2)4(1/4)2 3) that at least one will have white veins. 1-­‐(3/4)10 IV. Fill in the blank for each individual in the pedigrees below with the probability that he/she is heterozygous for the single gene dominant or recessive traits as indicated. Dominant Recessive 1 0 1 1 0 1 1 0 2/3 2/3 0 2/3 VI. Help resolve the mix-­‐up that occurred when the arm bands fell off 4 baby girls delivered almost simultaneously. The 4 mom’s and babies’ blood types could be checked immediately so start by eliminating any mom/baby combination, Fill in all blood groups that would eliminate any mother/baby pairs in the table below. Mom baby1 AB, MN, Rh+ baby2 O, M, rh-­‐ baby3, A,MN, rh-­‐ baby4 B, N, Rh+ ABO MN 1. AB, M, Rh+ ABO 2. O, MN, Rh+ MN 3. A, N, rh-­‐ 4. B, MN, Rh+ The husband of mom3 shows up first and he is typed as A, M, rh-­‐. Fill in any mismatches between this couple and the 4 babies below: baby1 AB, MN, Rh+ baby2 O, M, rh-­‐ baby3, A,MN, rh-­‐ baby4 B, N, Rh+ ABO, Rh MN ABO,MN, Rh Couple 3 The husband of mom4 arrives next and his type is AB, MN, Rh+. Fill in any mismatches between this couple and the 4 babies below: baby1 AB, MN, Rh+ baby2 O, M, rh-­‐ baby3, A,MN, rh-­‐ baby4 B, N, Rh+ ABO Couple 4 As best as possible, which baby should be sent home with each mom? Mom1 1 mom2 2 mom3 3 mom4 4 Give the potential ABO, MN and Rh genotypes for husbands (dads) for couples 1 and 2. Dad couple 1 AB, A, B; N, MN; Rh+/-­‐ Dad couple 2 A, B, O; N. MN; Rh+/-­‐ VII. Two Tt parents have dizygotic twins. If one twin is a taster, what are the odds the other will also be a taster? 3/4 Two Tt parents have monozygotic twins. If one twin is a non-­‐taster, what are the odds the other will be a taster? 0 Give an example of a human trait that is ‘present or absent’, yet is a quantitative (polygenic) trait Schizophrenia, cleft lip etc Would VT be higher in fraternal or identical twins? Frat Which varies more across countries: births of MZ or DZ twins? DZ VIII. For many plants, flowering is triggered when the days get shorter. A series of ‘maturity’ (ma) genes in sorghum reduce the time to maturity, ie the plants flower earlier while the days are still longer than normally would be the case. Use the following greatly simplified example to answer the questions. Two truebreeding sorghums are planted at the some time. One flowers in 64 days the other in 84 days. a) predict days-­‐to-­‐flowering in the F1 hybrid 74 b) F2 plants from self pollination of the F1 flower from 64 to 84 days. If five genes are involved, what fraction of the F2 progeny from selfing F1 plants flowered in 84 days and how many different days to flowering phenotypes would be expected in the F2? 84 day flowering fraction (1/4)5 Number of phenotypes 11 c) Is transgessive segregation occurring in this example? How do you know? No: extremes of F2 are 64 and 84, so not ‘beyond’ parents d) What is the average contribution of each contributing allele? 2 days e) Give a genotype for a true breeding 72 day flowering plant. A’A’, B’B’, CC, DD, EE f) Flowering day variance in the F2 was 8 but in the F1 it was only 2. What are the values of VT 8 VG 6 VE 2 H2 3/4