Consider the above pedigree of a cat mating. We are tracking the L locus that de
ID: 186715 • Letter: C
Question
Consider the above pedigree of a cat mating. We are tracking the L locus that determines cat hair length. Allele l is rare and causes long hair. In the pedigree, black indicate cats with long hair, and white indicates cats with short hair. Squares are males. Circles are females. The l allele is rare such that the probability of mating with an outbred carrier (i.e a non-relative) is effectively 0.
What is the mode of inheritance (autosomal dominant, autosomal recessive, X-linked dominant, or X-linked recessive)? Explain how you came to this conclusion by writing the genotypes of each member of the pedigree (either by hand on the pedigree or below)?
Genotypes:
I-1:
I-2: III-1:
II-1: III-2:
II-2: III-3:
II-3: III-4:
II-4: IV-1:
II-5:
5 4 3 4 2Explanation / Answer
L is dominant allele and causes short hair.
l is recessive allele and causes long hair.
LL or Ll = Short hair
ll = Long hair
Genotypes:
I-1 = ll
I-2 = Ll
II-1 = LL
II-2 = Ll
II-3 = LL
II-4 = Ll
II-5 = LL
III-1 = LL
III-2 = Ll
III-3 = Ll
III-4 = LL
IV-1 = ll
Some of the individuals such as III-1 and III-4 can be Ll