Final answer:
A normal female bird has a ZW sex chromosome combination. In birds, the ZW system determines sex, with ZW being heterozygous in females and ZZ being homozygous in males. This is different from the mammalian XY system.
Step-by-step explanation:
The correct answer to the question of what sex chromosomal makeup a normal female bird has is B) ZW. In birds, sex determination is based on the ZW system, where the presence of ZW (heterozygous) chromosomes constitutes a female, and ZZ (homozygous) chromosomes constitute a male. This system is the inverse of the mammalian XY system, where females are XX (homozygous) and males are XY (heterozygous). It's important to note that in birds, the female has the distinct sex chromosomes (ZW), rendering traits linked to these chromosomes more likely to appear in females since they are hemizygous.