In Campbell's Biology Chapter 14-15, Mendelian Genetics & The Chromosomal Basis of Inheritance, question 12 reads:
12) In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female?
A) 2:1 male to female
B) 1:2 male to female
C) 1:1 male to female
D) 4:3 male to female
E) 3:1 male to female
The correct answer is A. In my Punnett square, there were two male and two female so shouldn't the answer be C?