PS 3 answers, probs 3+4

PS 3 answers, probs 3+4 - Are 30% Br1 , 70% Br2 If...

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Problem 3. In mouse Hind III restriction digests, a certain probe picks a simple RFLP consisting of two alternative alleles of 1.7 kb and 3.8 kb. A mouse heterozygous for a dominant allele for bent tail and also heterozygous for the above RFLP is mated to a wildtype mouse that shows only the 3.8 kb-fragment. Thirty percent of the bent-tail progeny are homozygous for the 3.8kb allele, and 70 percent are heterozygous for the 3.8 and the 1.7-kb forms. a. Is the bent-tail locus linked to the RFLP locus? Explain your answer. B=bent tail, b= normal tail, r1=3.8 kb, r2=2.7 and 1.1 kb The cross is Bbr1r2 x bbr1r1 Progeny: 30% Bbr1r1, 70% Bbr1r2 Eliminating the contribution of the wildtype parent, the progeny
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Unformatted text preview: Are 30% Br1 , 70% Br2 If independent assortment exists, a 1:1 ratio of r1:r2 will be seen; r1 and r2 are clearly not assorting independently. Therefore, the two genes are linked with 30 m.u. between them. b. What RFLP bands do you predict among the wild-type offspring, and in what proportions? The cross Br2/br1 x br1/br1 70% br1/br1 or 70% wildtype have only a 3.8 Kb band 30% br2/br1 30% wildtype have 3.8, 2.7, and 1.1 Kb bands. Problem 4. mwm mom dad child 1 child 2 child 3 child 4 child 5 6 Kb 5 Kb 4 Kb 3 Kb 2 Kb 1 Kb _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ genotype +/-+/-+/+-/--/-+/+ +/-...
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This note was uploaded on 02/15/2012 for the course PMB 13 taught by Professor Freeling during the Spring '09 term at Berkeley.

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