What if the noun was masculine, would pelas then be pelos? Ex. Obrigado pelos cachorros?
I cannot reply to your answer above about how, "Obrigado pelas respostas" could be for "your" [answers], which I am guessing comes from "as" (as in "elas") being contracted with por? Or perhaps more like "P" from "por" + "Elas"? So in this case "as" stops being for "the" (definite determiner article) and becomes a personal (and possessive) pronoun instead for his/her, your (3rd person declension)?
Has this been explained yet up to this level of the Portuguese lessons?
Then that should be "obrigada" but we can picture a scene where two women are talking about a guy and the first asks: "what did he say?" Then she answers: "obrigado pelas respostas"
Yes, and it happens often .
I thought it was the gender of who you were saying it to that decides whether its obrigado/obrigada, not the gender of the person saying it?
Yes, here the man said "obrigado pelas respostas". It was a reported sentence.
That is certainly a possibility, but Duolingo tends to go for literal translations when the context is uncertain. For example, you wouldn't use "your" if someone hands you a sheet of answers written by a third party.
Why can't "thank you for your responses" be correct? It was marked incorrect.
joining together the ancient "per lo" (something like "for the") : pelo/pela = for the
I used the word "replies" but it was marked wrong. I then checked with a translation app and the word "repostas" was translated as both "answers" and "replies".