AAMC No. 4 107: Logic Q-analyzing between "good" & "best" choice

[SaintJude]

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Passage on cyroprotective role of glucose in wood frogs

107.) According to the passage, which of the following physiological conditions would increase a wood frog's chance of surviving freezing temperatures most effectively?

A. Dehydration
B. Ample live glycogen stores
C. High blood hemoglobin concentration
D. High tissue glucose concentration

I'm so upset b/c I narrowed down to B & D, but I just don't see why D is not an equally plausible answer.

The passage says:

Studies of the wood frog suggest that a main cyroprotective strategy involves accelerated glucose release from hepatic glycogen stores that consequently raise the glucose concentration of the body fluids

 

[chiddler]

Passage on cyroprotective role of glucose in wood frogs

107.) According to the passage, which of the following physiological conditions would increase a wood frog's chance of surviving freezing temperatures most effectively?

A. Dehydration
B. Ample live glycogen stores
C. High blood hemoglobin concentration
D. High tissue glucose concentration

I'm so upset b/c I narrowed down to B & D, but I just don't see why D is not an equally plausible answer.

The passage says:

passage says so :<

says it gets sugar from hepatosomething source = liver.

 

[SaintJude]

passage says so :<

says it gets sugar from hepatosomething source = liver.

Yes! But passage Also says the whole point of accelerate glucose release is to achieve high tissue glucose concentration ARgh

 

[rjosh33]

Yeah I put D as well after narrowing it to those two. I think they said the reasoning was that having chronically high tissue glucose is just as lethal as potentially freezing due to cold external temperatures. Therefore, the (ample) glucose needs to be stored as glycogen in the liver.

 

[SaintJude]

👍

 

[MedPR]

I think one of the graphs disproves answer D, but I'm not sure. I definitely remember getting this one wrong as well (I picked D).

 

[pfaction]

I think one of the graphs disproves answer D, but I'm not sure. I definitely remember getting this one wrong as well (I picked D).

Nope, it clearly states high glucose concentrations saved the frog, because I also got this wrong. I guess the high glucose concentrations are "transient" meaning ample glycogen stores will keep the glucose high...

 

[Mantis Toboggin]

Sorry to bump, but why wasn't the answer to this A? The net result of all of this is to dehydrate the cell in preparation for the cold. I understand that B is a requirement for what the passage stated, but my thought process was that *they didn't mention the accelerated breakdown of these stores so it can't be B."

Thanks.

 

[Sed8&Intub8]

Sorry to bump, but why wasn't the answer to this A? The net result of all of this is to dehydrate the cell in preparation for the cold. I understand that B is a requirement for what the passage stated, but my thought process was that *they didn't mention the accelerated breakdown of these stores so it can't be B."

Thanks.

Dehydration is not a protective strategy. It uses glucose from glycogen to decrease the freezing point and pull water out of the cells (dehydrating the cells) into the ECF and REDISTRIBUTES the water among the various fluid compartments such that only the extracellular water freezes.

 

[HinduHammer]

Weird - I got this question right but I thought it was ample live glycogen stores b/c it would break down into glucose and circulate in the blood, and the colligative property of having glucose in the blood would raise the FP of the blood and thus all the tissues that the blood circulated through, which provided the survival mechanism...is this not correct?

 

[Mantis Toboggin]

Dehydration is not a protective strategy. It uses glucose from glycogen to decrease the freezing point and pull water out of the cells (dehydrating the cells) into the ECF and REDISTRIBUTES the water among the various fluid compartments such that only the extracellular water freezes.

Wow brain fart moment. I don't know why I completely forgot amount the entire focus of the passage. Gotta give myself a break