Bio Question Dump

[dentalwannabe]

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Rather than everyone starting a new thread for their bio questions, maybe we can all just Ask and Answer here.

Here's my Q: Kaplan keeps saying that the Endoderm germ layer forms the (entire) respiratory tract. Other sources say it forms the tract LINING.

What is the truth?

 

[dentalwannabe]

Another Q:

The membrane that functions in respiration in the embryo is the
A amnion
B allantois
C chorion
D umbilical cord
E yolk sac

No good explanation was given for the "correct" answer, which I will post after some feedback. (please and thank you)

 

[21092109]

I think its C. The chorion is used for gas exchange and becomes the placenta in mammals.

 

[tomhrxbfg]

It's D I think. A is for shock protection, B becomes D at a later stage...C is for respiration but to a lesser extent. E is for nutrient.

Endoderm does form the lung, as well as the linings. Check wikipedia...

 

[dentalwannabe]

B allantois, was the answer given.

This is true for reptiles, birds, (and monotremes?), but they didn't specify in the question that the embryo was non-mammalian. I chose umbilical cord because in mammals that works with the placenta in gas exchange.

So...

 

[tomhrxbfg]

B allantois, was the answer given.

This is true for reptiles, birds, (and monotremes?), but they didn't specify in the question that the embryo was non-mammalian. I chose umbilical cord because in mammals that works with the placenta in gas exchange.

So...

Yea the question is not clear...only mammals have umbilical cord, I think the real DAT will be more specific

 

[dentalwannabe]

Wiki says (in case this helps anyone else): the trachea, bronchi, and alveoli of the lungs, the lining of the follicles of the thyroid gland and thymus, the urinary bladder and part of the urethra
+digestive tract stuff, all derived from the endoderm.

 

[dentalwannabe]

...I think the real DAT will be more specific

I hope for this daily when I run across questions like this.