AAMC #8 BS Question Item 142

[bdc142]

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Item 142:
Discovery that T = A and G = C in any given cell provides supporting evidence that:
A. the Watson and Crick model of DNA is correct
C. the genetic code is universal

I said C. Chargaff's rules apply in any cell (bacterial etc.) so if we take the genetic code to be DNA, then wouldn't it prove that it was universal? Also, Chargaff's rules were discovered before Watson and Crick

Thanks for any responses!

 

[jameschoun]

I don't think there is evidence for C... For MCAT purposes I believe they are referring to universal as the fact that mRNA transcripts from one organism can be translated in another organism...

Isn't part of the Watson-Crick model complementary base pairing? Thus answer = A

Your logic may be correct, I'm not quite understanding it still... But for MCAT purposes you need to go with the most direct answer.

My friend who is a really smart guy kept pulling in advanced outside information and pick the wrong answer through logic....

 

[TipToad]

No. It wouldn't prove that it is universal. For instance, what if we discovered a new species of bacteria that didn't use either DNA or RNA?

However, AT=CG would prove the Watson-Crick model. Go with the simplest choice.

 

[411309]

Watons model said that T was hydrogen bonded to A. So in other words he said that the amount of T was the same as the amount of A. So this discovery directly proves that idea.

 

[MedPR]

Watons model said that T was hydrogen bonded to A. So in other words he said that the amount of T was the same as the amount of A. So this discovery directly proves that idea.

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