Question

4. Three genes are mapped as shown below. The interference is -0.3. a fly homozygous for wildtype traits was crossed with a homozygous recessive. A female from F, was crossed with an ebony, rough eyed, brevis bristled male. Give the expected numbers of phenotypes out of a total of 2400. (6 marks) 5. Map these loci given the information below. Determine the order of the loci. Calculate the interference. (6 marks) wx/sh/V 50 Wx/Sh/v Wx/Sh/V 2100 wx/sh/v 2400 Wx/sh/V 780 Please answer both questions. Thank you wx/Sh/v 810 wx/Sh/V 120 Wx/sh/v 140 Total

Answer 1

Given interference value is megative re, -0.3), it means two genetic Tegions have move double Crossover than would be expected comedering the crossover hale of each regions. Greater megative inference suggest Combined mab length of adjacent region was sy aller or it means genes are linked. tighth Letus, Ebony-e, rough eye- brevis bristie - 6 G-wild-type) P- +++ A+++ X eberlebr fiy tat/ebr x ebrlebr . f2 is at 4+ /ebr cbrlebr tbr /etn ext/ebr Herental Scoregion I totoreby ebuleby 1 tbtlebr etrlehr - So region o DIO CitsioC (cc - l(-03) = 1.3 As the map distance is met provided, mot possible to calculate frequency of each phenohopes but one thing is clear from poor hver enester than I CCM imeans there is only Single Cosv. mod.CO. Highest frequency of honapper gre of bovenal senot be conile the feat show double cuss wes reston and according to given frequency Exishvi l i js are baremtare while rih and W hite Showing cluble now over and it means geve, present in between wx on $h Hence dyder o gen Shutd be eithes WX-V-sh oy Sh VW Map dised - Doponce between Wup on (120+46) + (50.4721 5.9 59 CM (abbay) Distance betwee vana sh 150.- 210)+(50492) X 6472 Mab = 26.457 m 2645 CM. Cabbrox) 6472- X100 WX V sh 5.9-7- 26-45 Here of actual cross over (double) 650++2) Xtovy. leereble) 647.2) 100). % expected .887. (abbrox) double crossover - 5.94 of 26-4.5% We hicient of O eficient of coincidence coincidence :(.actual de Coly expected d.CO) ( v 1 .567. Cabbrox), (6) (1.88774587.) = 3.21%abbrox.). 0.0121 As Co Interference = (1-C.C.) > I-Dok21.). = 0.9879 Cabbroy)