Male chicken = Galo
Female chicken = Galinha
Roasted chicken = Frango assado
This is correct but don't explain it. I think that frango refers to the type of meat (here from a chicken). Like you have carne bovina (beef) e carne suína (pork).
Is Portuguese like Spanish in the sense that there are separate words for a living chicken and the chicken you eat?
It's actually the same. Frango for an alive chicken and frango for a fried chicken.
Galinha in portuguese and "gallina" in spanish is the word for an adult female chicken that can also be eated an you ca say: "a menina come galinha"
It depends which part of Brasil you are from. Some say Galinha and some Frango