Question

Total fingerprint ridge count exemplifies a polygenic inheritance pattern. Penrose (1969) and others have suggested that a minimum of seven gene loci contribute to TRC, but a fourlocus model is hypothesized in the problems that follow. Thus, AABBCCDD represents the genotype for maximum ridge count and aabbccdd symbolizes the genotype for the minimum ridge count. Assume that each active (dominant) allele adds 12 ridges to the TRC of the male and 9 to the TRC of the female and that having the genotype aabbccdd produces a baseline TRC of 80 for males and 70 for females.

If an AaBbCcdd male mates with an AaBbCCDD female

b. What is the minimum number of ridge-producing alleles possible in one of their children?

c. What would be the TRC for this child if it is a male?

d. What would be the TRC for this child if it is a female?

e. If this child is a male, will he have a higher or lower TRC than the parent with the lower ridge count?

f. What is the maximum number of ridge-producing alleles possible in a child of this couple?

g. If this child is a female, will she have a higher or lower TRC than the parent with the higher ridge count?

Please help me with all of the questions and show your working out so I can understand. Thank you

Answer 1

Answer-

This is an example of additive gene interaction, where each additive allele adds its effect to the baseline genotype (aabbccdd).

Explanation for all answers is given below: