1. At a local piggery, the pigs have varying tail lengths with a herd mean of 18 cm, and
   

variance of 8 cm². The farmer

crosses boars with a 6 cm tail to sows with a 30 cm tail. The

mean

tail length in the piglets is approximately 18 cm, with variance of 1 cm². If these

piglets

are allowed to interbreed the full range in tail lengths is restored and

approximately 3% of the piglets have extreme phenotypes. The farmer also selects a

core group of pigs with a mean tail length of 10 cm, and when bred with the general

herd, they produce piglets with a tail length of 13 cm.

ADiscuss the mode of inheritance of this trait, with reference to (i) the total genetics

effects, (ii) the transmittable genetic effects, (iii) the effects of the environment, (iv)

the number of genes involved and their mean allelic contributions (show all

calculations)

BIf the farmer were to randomly mate a group of pigs with mean tail length of 20

cm, what will the predicted tail lengths be in the resulting piglet cohort?

CIf a 6 cm pig is mated to a F1 pig what will be the predicted phenotypic ratios in

the resulting litter?