data analysis question

[echoyjeff222]

Full copy of the passage here: http://books.google.com/books?id=Xq...ed an increase in TNF gene expression&f=false

This is from one of Kaplan's exams ... the question asked:

I do not get why it is A and not B. Here is the explanation:

I do not get why it says "in activated cells the GREATER the TAT the less TNF" and I do not see that. In d1 vs d2, we have increased TAT (100) correlating to MORE TNF.

Let me know if you need more details from the passage ... I am feeling reaaaally confused ... are their numbers wrong?

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[texan2414]

Hey I'm confused with this question as well,

In the non-activating experiment, the increase in concentration of Tat (c2 to c1), the expression of TNF-a increased.

Now, we expect that the mitogen PHA would stimulate together with Tat would activate lymphocytes in a signaling pathway that is mediated by TNF-a. Thus, activation of lymphocytes would presume an increase in all PHA, Tat, and TNF-a concentrations. This is corroborated by the data d2 vs d1.

Now the question asks what experimental result would contradict the above trend. Clearly we expect concentrations of PHA/Tat to be directly proportional to TNF-a; any experimental result that shows otherwise contradicts our initial supposition. Looking at PHA-stimulated cell line with Tat when compared to its control (d2/d1 vs. b) shows an inverse/contradictory correlation. Thus, you can say that both A and B are correct answers for this.

There is no reasoning given why B is inappropriate to compare with the control. I would like to know this as well.

 

[texan2414]

Nobody else tackled this?

 

[echoyjeff222]

I think it was too much work

Or, people just got scared away by the big graphs and numbers.

 

[yjj8817]

Maybe they made a mistake?