Question

What are examples of sex chromosomes in different species?

1) XX/XY (mammals, flies)
2) XX/XO (C. elegans)
3) ZZ/ZW (butterflies, moths, birds)
4) All of the above

Answer 1

In mammals, sex is determined by XX/XY and sex determination in birds, butterflies, moths, and reptiles is ZZ/ZW.

Step-by-step explanation:

In mammals, sex is determined by the presence of XX (homozygous) in females and XY (heterozygous) in males. For example, humans, dogs, and flies have this XX/XY system. In birds, butterflies, moths, and reptiles, sex is determined by the presence of ZZ (homozygous) in females and ZW (heterozygous) in males.