Question

PROBLEM SET 2 For each of the questions provide answers in a separate document that you will submit via a dropbox that will be created on the course's blackboard site. Please show your calculations or use point form. Only answer what is being asked. When the question asks for genotypes, use standard notation (e.g. +/m, Ala, XX"). Note that the point value for each question is indicated in parentheses beside the question number. 1. (1) A true breeding strain (S1) of guinea pig has dominant alleles for fur texture (R). fur colour (C), and hair length (L). Another strain (S2) is homozygous for the recessive alleles of all three genes. The three genes are linked and arranged on the chromosome as follows: R-------7m.u. ------------ - 18 mu, The F1 trihybrid between the two strains is backcrossed to strain S2. Assume that there is no interference. A) What proportion of the backcrossed progeny will resemble strain S1 for all three traits? B) What proportion of the backcrossed progeny will resemble strain S2 for all three traits? C) What proportion of the backcrossed progeny will resemble strain S1 for R and L but strain S2 for C? D) What proportion of the backcrossed progeny will resemble strain S1 for Rand but strain S2 for L?

Answer 1

Tive Brooling Parent Parent c e t c S2 Given Interference =0 - Conssence of wellicant observed bouse Cross wer Expectal e Expedes om = 0.37X0-18 = 0.0126 Assume Tutar Proson 2100 - Obsernas do = 1x0 .0126 = 0.0126 -0.0126 x 1000= 12.6 c . Si bor RAL + = 12.6 = 6 = = . Sz bor e - 13 Sinsle crosu wer between C 4L +x+12 I. RF C4 L = 1000 180= 2x+12 271 = 168 x=84. Answer = 84000 REC= x + x4 22 X100 RF A Sinsie God war blow Rac 19 To = 2x+12 2x = 58 26=29. Parental offspans = Total (SiO RAC & SW (AL tow) = 109 - (58+ 168 +12) lo- -762 . 'S, = 762/2 = 381 Proportion 3311-> B) S2 = 381/1000