Meet Charlie. Charlie is an Australian Shepherd. He is a blue merle. “Merle” is the black, grey colouring of his spots. Coat colour is an autosomal trait. His Mom is a blue merle and his dad has a red and white coat (not a merle). If two merle coated Australian Shepherds are crossed, there are genetic troubles. The offspring of two merle parents can be “double merles”. These dogs have irregular white markings in that they are mostly white, with not much merle on them. They have vision and hearing defects to varying degrees; some are both blind and deaf. They are sometimes called “lethal whites”. “Double merles” are homozygous for the merle gene. When an Aussie inherits ONE merle gene copy, it is a normal merle. Statistically, one quarter of the progeny of merle-to-merle mating will be double merles. Is the double merle a lethal genotype? Show a Punnett square that illustrates how a double merle is created. What is Charlie’s genotype for coat colour?
Meet Charlie. Charlie is an Australian Shepherd. He is a blue merle. “Merle” is the black, grey colouring of his spots. Coat colour is an autosomal trait. His Mom is a blue merle and his dad has a red and white coat (not a merle).
If two merle coated Australian Shepherds are crossed, there are genetic troubles. The offspring of two merle parents can be “double merles”. These dogs have irregular white markings in that they are mostly white, with not much merle on them. They have vision and hearing defects to varying degrees; some are both blind and deaf. They are sometimes called “lethal whites”.
“Double merles” are homozygous for the merle gene. When an Aussie inherits ONE merle gene copy, it is a normal merle.
Statistically, one quarter of the progeny of merle-to-merle mating will be double merles.
Is the double merle a lethal genotype? Show a Punnett square that illustrates how a double merle is created. What is Charlie’s genotype for coat colour?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
