mean fat content can be expected in the descen-dants of these animals? 6. Suppose that two triple heterozygotes A / a ; B / b ; C / c are crossed. Assume that the three loci are in different chromosomes. a. What proportions of the offspring are homozy-gous at one, two, and three loci, respectively? b. What proportions of the offspring carry 0, 1, 2, 3, 4, 5, and 6 alleles (represented by capital letters), respectively? 7. In Problem 6, suppose that the average phenotypic effect of the three genotypes at the A locus is A / A 5 4, A / a 5 3, and a / a 5 1 and that similar effects exist for the B and C loci. Moreover, suppose that the ef-fects of loci add to each other. Calculate and graph the distribution of phenotypes in the population (as-suming no environmental variance). 8. In Problem 7, suppose that there is a threshold in the phenotypic character so that, when the pheno-typic value is above 9, an individual Drosophila has three bristles; when it is between 5 and 9, the indi-vidual has two bristles; and when the value is 4 or
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This note was uploaded on 01/10/2011 for the course BIOL BIOL taught by Professor Johnson during the Spring '08 term at Aberystwyth University.