Practice: Wild type fruit flies have red eyes. A white-eyed female fly is crossed with a red-eyed male fly. All of the females from the cross are red-eyed and all of the males, white-eyed. What type of inheritance pattern is this?
Concept #1: Sex-Linked Inheritance
Concept #2: X-Linked Inheritance
Practice: Wild type fruit flies have red eyes. A white-eyed female fly is crossed with a red-eyed male fly. All of the females from the cross are red-eyed and all of the males, white-eyed. What type of inheritance pattern is this?
Practice: When Thomas Hunt Morgan crossed red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?
Concept #3: X-Linked Recessive Disorder: Hemophilia Inheritance
Practice: Women with X-linked disorders always pass the genes for the disorder on to ______. While men with X-linked disorders always pass the genes for the disorder on to _______.
Concept #4: X-Linked Recessive Pedigrees
Example #1: What is the inheritance pattern of the following pedigree?
Practice: The following pedigree is for the X-linked-recessive trait for color blindness. Using XN for the normal allele and Xn for the color blindness allele, fill in the top half of the boxes/circles with the genotype. Also, fill in the bottom half of the boxes/circles with the phenotype (Normal vision or color blind). If it is impossible to know for certain a specific allele in the genotype, then place a “?” to represent the allele that is in question.