AAMC 5 more bio

[chiddler]

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Really need the passage for this since this organism is so unusual, if you don't remember this.

1. An extra S phase occurs during amitotic division in a small macronucleus to minimize fluctuations in DNA content. This is most likely trigerred by the presence of:

A. low concentratiosn of DNA in the macronucleus
C. High concentrations of DNA in the micronucleus
D. Mitotic enzymes in the micronucleus

answer is A.

 

[MedPR]

This passage was the hardest BS passage on all the AAMCs combined. I basically guessed all the way through it. It's no surprise that AAMC 5 was my lowest score.

Sorry I can't help, but imo none of the BS passages were anywhere near as difficult as this one so that should be encouraging.

 

[pfaction]

I mean, I logic'd it out that there's no point in duplicating twice unless there was a decrease in DNA concentrations.

 

[chiddler]

This passage was the hardest BS passage on all the AAMCs combined. I basically guessed all the way through it. It's no surprise that AAMC 5 was my lowest score.

Sorry I can't help, but imo none of the BS passages were anywhere near as difficult as this one so that should be encouraging.

so much relief! i'm so happy to have read that lol

i only got 1 question right from this passage and it was the easy obvious first one "what does sexual reproduction do"!

 

[pfaction]

I got the next two wrong, about cytoplasm (hit myself in the head for that, should've remembered polar bodies)...everything else right

 

[Morsetlis]

Well, the point was that S phases are when cells replicate their DNA. For DNA stability, with so much chaos (serious, wtf was that), either additional DNA replication would be needed, or additional CHECKPOINTS would be needed. Remember that G<->S transitions contain checkpoints, especially in eukaryotes, although there could be some proofreading, etc in prokaryotes too.

 

[chiddler]

Well, the point was that S phases are when cells replicate their DNA. For DNA stability, with so much chaos (serious, wtf was that), either additional DNA replication would be needed, or additional CHECKPOINTS would be needed. Remember that G<->S transitions contain checkpoints, especially in eukaryotes, although there could be some proofreading, etc in prokaryotes too.

I understand this and understood it before you wrote this, but I don't see how this knowledge can help answer this question.

Can you please explain?

 

[kasho11]

When I was going through it today, I was first of all like wtf is this sh.it, where are all these genomes, chromosomes, and multiple replication things coming from.

But my thinking was this: What would trigger an extra S phase. Well S phase is where DNA replicates so it should be something to do with the amount of DNA. If you read the last paragraph of the passage where it talks about the extra or removed S phase it is all about the MACRO nucleus, so any answer choice regarding the micronucleus would most likely be incorrect.

I don't remember what choice B was but a low concentration of DNA in the macronucleus would seem like a good trigger for an extra S phase of the macronucleus, (to make more DNA) doesn't it?


Edit and on that other bio question, microtubule or plasma membrane, I went back and forth for at least 3 minutes and finally chose microtubules because I was thinking most plasma membranes wouldn't have receptors for Ach, I'll read the explanation tomorrow but I thought only certain cells would have ach receptors, but I guess microtubules have no ach receptors whatsoever, so kind of silly, damnit.

 

[752779]

Got lost in this passage too. Would this be the right reasoning regarding the order of cell division?:

When there is a low concentration in DNA, (INTERPHASE) there will be an extra S phase to replication of more chromosome. (in bacteria only). This would lead to an amitotic division in mitosis, where there are 2 uneven nuclei.