Genetics

6. Assume that the height of tobacco plants is controlled by five genes. Two different alleles exist for genes A, B, C, and D, but only one allele for gene E is present in the population. The effect of each genotype on height is listed below. Total height is the sum of the effects of each of these five genes. 
 
Gene A       Gene B       Gene C       Gene D       Gene E
AA + 6 cm    BB + 10 cm    CC + 8 cm    DD + 2 cm    EE + 40 cm
Aa + 3 cm       Bb + 5 cm        Cc + 5 cm       Dd + 2 cm   
aa + 0 cm       bb + 0 cm        cc + 2 cm       dd + 0 cm   
 
a. What is the maximum height possible in the population and which genotypes will have
this phenotype (4 pt)?

b. What fraction of progeny produced from the following cross will be exactly 42 cM tall:
AaBbCcddEE x AaBbCcddEE (4 pt)?