genetics question?

Question

a black lab has puppies. she has 9 black w/black nose, 3 black w/pink nose, 3 white w/black nose and 1 white w/pink nose. The 1 white w/ pink nose dies


what is the type of cross?
I put dihybrid, is that correct?

suggest an explanation for the death of the puppy.


I have no clue here...why would it die?
Ex

Answer 1

sounds like a heterozygous X heterozygous cross (the ratio gives it away 9:3:3:1). I believe there is a lethal combination in the two recessive genes that makes up phenotype of the last puppy that died (albino).

Answer 2

this is a case of allelic interaction of the two genes. i believe it is a case of complementary polygenic cross where the dominant allele of one gene inhibits the dominant allele of the other gene. hence if the dominant allele of the first gene is present in the genotype at all the colour becomes that represented by the first gene. as for the death there is a lethal combination of the recessive alleles of the two genes. in fact in the case of mice colour there is homozygous dominance lethality.
i am sorry but don't remember exactly what it is called.