more Kaplan confusion (placental development)

[wall1two]

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kbb 7th edition, practice test bio number 11,

which of the following is involved with respiration and excretion and develops into the placenta in humans?

their answer is the allatois, which i know is involved in respiration and excretion but doesn't it, along with the yolk sac, develop into the umbilical cord? another answer choice is the chorion, which develops from the trohpoblast, and was my answer.

am i wrong or is this another mistake by kaplan? the online biology section they put out was disgraceful and makes me second guess their answers.

 

[Kahr]

They do have mistakes, though I wouldn't assume Kaplan is absolutely rife with them, so don't start feeling paranoid man, won't do you any good! 🙂

This is why I love this forum, good check for your own knowledge. So, upon careful reading through Campbell, I found an answer to your question. You are correct, the chorion develops into the placenta.

chorion (kor'-e-on) The outermost offour extraembryonic membranes. It functions in gas exchange and contributes to the formation of the mammalian placenta. From Campbell.

However, you should keep in mind that had the question left out the part about the placenta, allantois would have been a good answer, as it does, like you said, develop into the umbilical cord.

Thanks for addressing this, very good eye my man.

Cheers


Edit: Just want to add that upon doing some extra reading at Wikipedia, it confirms this information, also provides some other interesting details, perhaps beyond the DAT, but good nonetheless. http://en.wikipedia.org/wiki/Placenta