In Birds, Sex Is Determined by ZW Chromosome Inheritance

Multiple Choice

In birds, sex is determined by ZW chromosome inheritance. Males are ZZ and females are ZW. Within pigeon populations there is a recessive, Z-linked allele that is lethal in embryos. What is the expected sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a wildtype female?

A) 2:1 male to female
B) 1:2 male to female
C) 1:1 male to female
D) 3:1 male to female