I have a question in regards to question # 76 from passage 12 in the AAMC Biology Q-Pack Vol. 1:
I'm having trouble understanding why the gene encoding UV-reflectance pigment wouldn't be on a Y or sex chromosome if only males have the dewlap. How is the fact that the pigment is expressed in the dewlap, a structure found only in males, not sufficient to conclude that the gene would be on a Y chromosome?