MCAT Bio..What to Expect..Hope this Helps

[Knocked Up]

Ok, I'm not a bad guy. I preach that the MCAT is by far the most important aspect of your application, but I never actually post on this side of the forum. I've got some time to kill before med school starts in the fall, and I just finished a paper. I decided to post the abstract and ask a few questions to show you guys what skills you need for the "new" MCAT Bio before I got out tonight. I hope this helps. Passage below and some questions after that.

------------------

Inflammation is linked clinically and epidemiologi- cally to cancer, and NF-kB appears to play a causa- tive role, but the mechanisms are poorly understood. We show that transient activation of Src oncoprotein can mediate an epigenetic switch from immortalized breast cells to a stably transformed line that forms self-renewing mammospheres that contain cancer stem cells. Src activation triggers an inflammatory response mediated by NF-kB that directly activates Lin28 transcription and rapidly reduces let-7 micro- RNA levels. Let-7 directly inhibits IL6 expression, re- sulting in higher levels of IL6 than achieved by NF-kB activation. IL6-mediated activation of the STAT3 transcription factor is necessary for transformation, and IL6 activates NF-kB, thereby completing a posi- tive feedback loop. This regulatory circuit operates in other cancer cells lines, and its transcriptional signature is found in human cancer tissues. Thus, inflammation activates a positive feedback loop that maintains the epigenetic transformed state for many generations in the absence of the inducing signal.

-------------------

1) First, whenever you see a passage like this ALWAYS draw out the pathway. So do just that. Use --> for stimulates and ---l for inhibits.

2) Based on the passage how can NfkB be classified.
a) a restriction factor
b) a transcription factor
c) a DNA methyl transferase
d) a cytokine

3) If the scientists in the passage had over expressed in let 7 in the cell lines, what effect would this have on cellular transformation.
a) It would increase levels of cellular transformation.
b) Decrease levels of cellular transformation.
c) Have no effect since IL6 positively feedbacks on NFKB leading to cellular transformation regardless of let 7.
d) WTF? Who cares, these questions are nothing like the Kaplan tests...

4) Overexpression of SRC in cell lines of Stat 3 -/- mice would have which of the following effects?
a) Epigenetic switch leading to increased cellular transformation.
b) Decreased expression of Lin28.
c) Lower levels of inflammation due to down regulation of IL6.
d) Increased levels in Lin28 and IL6, yet no epigenetic switch to cellular transformation.

5) Which of the following statements is false?
I) The mechanistic regulation of cellular transformation described is dependent on changes in DNA sequences of target genes.
II) IL6 positively feedbacks on NFKB.
III) Overexpression of Lin28 in breast cells leads to increased levels of cellular transformation.

a) I
b) II
c) III
d) I and III
e) II and III
f) I and II

---

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[breeniee]

Pretty cool that you took the time out to write this for us.... I did the questions and would like to know the answers (hehe)!

 

[fas376]

if my passage looks like that tomorrow, i'm going to jump in front of a bus

 

[breeniee]

if my passage looks like that tomorrow, i'm going to jump in front of a bus

Really? I don't think I'd jump in front of a bus if I saw something looking like that....

But I definitely would if you needed to apply background knowledge too. Like a crazy looking cause and effect, positive and negative feedback loop that included confusing hormones or neurotransmitters which aren't defined in the passage but that you were supposed to remember. I think I'd cry then because deciphering a passage and also applying that sort of knowledge is killer. I think that's how the MCAT might be though from what I remember when I took it in 2009. I'm sure it's even more scientific-paper-like now than 3 years ago. If mine were more like the above, I'd gladly take it.

 

[411309]

I don't understand your answer key?

 

[typicalindian]

I hope on my version of the MCAT they don't decide to include 6 answer choices instead of the regular 4 thanks for typing this out though

 

[411309]

I am super confused on the answer key still, Lol

 

[EnginrTheFuture]

Ripped through it but didn't have paper to use. Probably bombed because writing it down the mechanism would have helped a lot. Answer key?

I got:

d
a
a but maybe d
f but maybe b

 

[breeniee]

I don't understand your answer key?

There is no answer key. The last bit is just question 5. Roman numerals and then a,b,c,d,e,f


and I got
2. B
3. B
4. D
5. D???

EDIT: Awaiting answer key still.... Wow this is really bugging me, haha.

 

[411309]

bahah oh, Im too tired -_-. I tried to match my answers to it and was like wtf..I dont get it ;p

 

[shoenberg3]

I like these questions.
I quickly tried them and got b, b, d, c

What's the answer?

 

[kasho11]

Running through it once over I'm saying b, b, d, c. Btw what happened to #2?

And yeah biochemistry seemed really intimidating to me when I first started, until I realized everything is basically either a protein or DNA/RNA, big/weird names just makes things seem more difficult than they are. Pretty basic pathway with an inhibition step resulting in positive feedback at the end.


Edit And by new bio do you mean the current BS section and its trend toward more critical thinking, or the future biology section for 2015? Or both?

 

[SaCkO]

I was eating when i saw this.. I had to stop chewing to connect some stuff in pathway ..lol
anways my answers
2) D
3) B
4) D
5)A


Nice passage Btw , and I can really see this coming as a pathway on MCAT with a similar style
Thank you for your effort.. Waiting for the Answer Key

 

[shoenberg3]

There is no answer key. The last bit is just question 5. Roman numerals and then a,b,c,d,e,f


and I got
2. B
3. B
4. D
5. D???

EDIT: Awaiting answer key still.... Wow this is really bugging me, haha.

You changed your answers drastically

 

[gentlebeast]

B
B
D
A
Is the style of this passage close to real test? Could someone take the test recently say something?
It does look like verbal......

 

[shoenberg3]

I like these questions.
I quickly tried them and got b, b, d, c

What's the answer?

Actually i meant, b, b, d, d
Forgot that it was asking for what was false. let's hope i dont make silly mistakes like that on the real thing...

 

[railgun]

I got b, a, ??, c
For 3, Let-7 directly inhibits IL6 expression, resulting in higher levels of IL6 than achieved by NF-kB activation... this doesn't really make sense bcuz if IL6 is inhibited shouldn't the levels be lower
I think I'm supposed to know this stuff as the lab i work in also researches inflammatory response (but in endothelial cells) .

 

[StilgarMD]

Inflammation is linked clinically and epidemiologi- cally to cancer, and NF-kB appears to play a causa- tive role, but the mechanisms are poorly understood.

didn't strike me as useful info

We show that transient activation of Src oncoprotein can mediate an epigenetic switch from immortalized breast cells to a stably transformed line that forms self-renewing mammospheres that contain cancer stem cells. Src activation triggers an inflammatory response mediated by NF-kB that directly activates Lin28 transcription and rapidly reduces let-7 micro- RNA levels. Let-7 directly inhibits IL6 expression, re- sulting in higher levels of IL6 than achieved by NF-kB activation. IL6-mediated activation of the STAT3 transcription factor is necessary for transformation, and IL6 activates NF-kB, thereby completing a posi- tive feedback loop. This regulatory circuit operates in other cancer cells lines, and its transcriptional signature is found in human cancer tissues. Thus, inflammation activates a positive feedback loop that maintains the epigenetic transformed state for many generations in the absence of the inducing signal.

the Bolded sentence makes no sense to me, since it seems like a straight up contradiction. NFkB reduces Let7 microRNA, which upregulates Let7, which directly inhibits IL6... and IL6 activates NFkB... and this counts as positive feedback? im pretty sure this is negative feedback.
-------------------

1) First, whenever you see a passage like this ALWAYS draw out the pathway. So do just that. Use --> for stimulates and ---l for inhibits.

2) Based on the passage how can NfkB be classified.
a) a restriction factor
b) a transcription factor - "mediated by NF-kB that directly activates Lin28 transcription"
c) a DNA methyl transferase
d) a cytokine

Note: If you've worked in a cell bio lab or taken immunity, you know "NF" means "Nuclear Factor", and its up there with "NFAT" - nuclear factor of activated T cells, i forget what kappa B does (probably B cells)

3) If the scientists in the passage had over expressed in let 7 in the cell lines, what effect would this have on cellular transformation.
a) It would increase levels of cellular transformation.
b) Decrease levels of cellular transformation.
c) Have no effect since IL6 positively feedbacks on NFKB leading to cellular transformation regardless of let 7.

According to the passage, Let7 both upregulates and downregulates IL6. given the direct sentence and not the inference, Let7 inhibits IL6, "IL6-mediated activation of the STAT3 transcription factor is necessary for transformation", so no IL6, no transformation.


4) Overexpression of SRC in cell lines of Stat 3 -/- mice would have which of the following effects?
a) Epigenetic switch leading to increased cellular transformation.
b) Decreased expression of Lin28.
c) Lower levels of inflammation due to down regulation of IL6.
d) Increased levels in Lin28 and IL6, yet no epigenetic switch to cellular transformation.

Note: i just jumped to the end and knew whatever STAT3 did (transformation) could not take place since its a knockout, so A is out. SRC still does all its own witchcraft (upregulating Lin28 - B is wrong), (Downregulating IL6 [depending on how you read it] so C is true). D could be true, again, depending on whether you believe the "positive feedback" thing, or if you believe the exact line i.e. "IL6 activates NF-kB, thereby completing a posi- tive feedback loop". if you take that line at face value, SRC downregulates IL6, and D is wrong. if you don't, then D and C are both correct.

5) Which of the following statements is false?
I) The mechanistic regulation of cellular transformation described is dependent on changes in DNA sequences of target genes. - This is clearly false, the entire passage is about transcription factors, and the only time i hear DNA ever being manipulated is in lymphocytes rearranging their B cell receptor (antibody) or T-cell receptor genes.
II) IL6 positively feedbacks on NFKB. - according to the passage, NF-kB downregulates IL6, ...yet it says "IL6 activates NF-kB, thereby completing a posi- tive feedback loop". i'd have to say true because yet again, its a direct statement in the passage.
III) Overexpression of Lin28 in breast cells leads to increased levels of cellular transformation. - Lin28 upregulates Let7, which inhibits IL6, which is needed for STAT3transformation, so this is also false

a) I
b) II
c) III
d) I and III
e) II and III
f) I and II[/QUOTE]

my choices
B, B, C, and D.

if anyone thinks im making up the contradiction, please explain it to me =P

 

[breeniee]

You changed your answers drastically

Yeah and I have a big question mark next to it. And I see you did too. I think the lack of an answer key is making us all figity

 

[Knocked Up]

Ok, back now. I didn't make up the passage, it's directly from Cell. I just made the questions. Here's some question answers, I need to hit the bed now, fun night.

1) Src ---> nFkb ----> Lin28 -----l let 7

nFkb <------ IL6 l------- let 7

IL6 ------> Stat 3

2) B "NF-kB that directly activates Lin28 transcription"

3) B. Let 7 microRNA inhibits IL6...it's a negative regulator in this pathway...so down regulate Stat 3 and down regulate cell transformation

4) D. Stat 3 is knocked out (as will I be in a few minutes)

5) A. look for key words on the MCAT people "Src oncoprotein can mediate an epigenetic switch"

Good night to all and good luck, I'll come back to answer more questions in the morning when I'm a little more sober and can think straight.

 

[Knocked Up]

Yeah let me know if this crap is helpful to you guys. From my experience last year, the passages were like this. Kaplan's aren't and neither are anyone else's. I can make more if they are helpful. I tutor for the MCAT and my students hate me for making these crappy passages.

 

[shoenberg3]

On last question, are you sure just based on the excerpt, III is shown to be true?

EDIT: I guess the wording was asking for something false (shown to be false?), but I still maintain that it doesn't seem to be directly suggested based on the passage, although of course it may well happen IRL.

 

[shoenberg3]

1) Src ---> nFkb ----> Lin28 -----l let 7

nFkb <------ IL6 l------- let 7

For me, it wasn't really clear that Lin28 inhibits let 7 from this: "mediated by NF-kB that directly activates Lin28 transcription and rapidly reduces let-7 micro- RNA levels."

It read more like NF-kB upregulating Lin28 and downregulating Let-7, instead of NF-kb upregulating Lin28, the latter of which downregulates Let-7.

This is why I can't seem to agree with the answer to the final question.

And please do post more of these! I think these are very good practice.

 

[StilgarMD]

4) D. Stat 3 is knocked out (as will I be in a few minutes)

5) A. look for key words on the MCAT people "Src oncoprotein can mediate an epigenetic switch"

First off, i think the question is great, and i hope you make many more.

2nd, i disagree with your answer to 5. Epigenetics is not a change in DNA sequence, as im sure you know, its a change in the availability of that DNA to be read by transcription machinery via packaging at Euchromatin (loosely bound around acetylated histones) or Heterochromatin (tightly bound around non-acetylated [hence more positively charged] histones). if im mistaken let me know.

3rd, i don't know if i agree with your chain

Src activation triggers an inflammatory response mediated by NF-kB that directly activates Lin28 transcription and rapidly reduces let-7 micro- RNA levels.

the passage does not say:

Src ---> nFkb ----> Lin28 -----l let 7

It says:

Src --> NF-kB --> Lin28

NF-kB --I miRNA of Let-7

miRNA is like small interfering RNA, it binds to complementary sequences and blocks translational machinery from being recruited, along with recruiting nucleases.

so NF-kB --I miRNA of Let7

is actually NF-kB --> Let7

correct me if im wrong =P

Edit:

Ok, so i went and checked out the paper

"Let-7 microRNA directly inhibits expression of IL6
MicroRNAs exert their biological functions through suppression of target genes via RNA-RNA complementarity. Using three different selection criteria (Figure S7), we identified interleukin-6 (IL6) as a potential gene target of let-7."

so Let7 miRNA isn't miRNA against Let7, it's miRNA against IL6, and is called Let7... i REALLY hope they are clearer on the MCATs, but it is excellent practice to pick apart these problems. the chain actually is as Knocked up describes it.

 

[shoenberg3]

First off, i think the question is great, and i hope you make many more.

2nd, i disagree with your answer to 5. Epigenetics is not a change in DNA sequence, as im sure you know,

I'm sure everyone agrees with this and hence I is false.

I agree with you on the other point though.

 

[StilgarMD]

Right lol idk why i read that differently the 2nd time. i guess our only disagreement is on the chain of events.

 

[Postictal Raiden]

First off, i think the question is great, and i hope you make many more.

2nd, i disagree with your answer to 5. Epigenetics is not a change in DNA sequence, as im sure you know, its a change in the availability of that DNA to be read by transcription machinery via packaging at Euchromatin (loosely bound around acetylated histones) or Heterochromatin (tightly bound around non-acetylated [hence more positively charged] histones). if im mistaken let me know.

3rd, i don't know if i agree with your chain



the passage does not say:

Src ---> nFkb ----> Lin28 -----l let 7

It says:

Src --> NF-kB --> Lin28

NF-kB --I miRNA of Let-7

miRNA is like small interfering RNA, it binds to complementary sequences and blocks translational machinery from being recruited, along with recruiting nucleases.

so NF-kB --I miRNA of Let7

is actually NF-kB --> Let7

correct me if im wrong =P

Edit:

Ok, so i went and checked out the paper

"Let-7 microRNA directly inhibits expression of IL6
MicroRNAs exert their biological functions through suppression of target genes via RNA-RNA complementarity. Using three different selection criteria (Figure S7), we identified interleukin-6 (IL6) as a potential gene target of let-7."

so Let7 miRNA isn't miRNA against Let7, it's miRNA against IL6, and is called Let7... i REALLY hope they are clearer on the MCATs, but it is excellent practice to pick apart these problems. the chain actually is as Knocked up describes it.

Exactly. For I moment I thought I was reading the question wrong because I'm an ESL.

 

[UrshumMurshum]

Lol I got the last one wrong because I thought it was asking for the true statements and not the false one.

This seemed like a reasonable passage, I mean it's a little biochemistry-ish sounding, certainly not something I encountered in bio I and II. But I was able to understand roughly what -/- meant despite never seeing that notation.

 

[SaintJude]

Thanks KnockedUp--one of the most useful posts I've read this week.

 

[gentlebeast]

Even though I answered right, this passage seems much harder than passages I've done. Thank you, op! At least we have an idea of the real thing.

 

[crazedpiggy]

Don't mind me bumping this, but after taken the 9/2/2011 MCAT, I have to agree with the points OP made.

The new BS section was a huge surprise for me - it was almost like all of the non-Orgo passages were something from scientific journal abstracts, which made the section almost a continuation of VR where you could answer 75-80% of the questions without having to know a single thing that the prep-books stressed. As a result, I panicked and got about 3 pts lower than my AAMC average on BS. Hence, I am studying for retest.

It's strange because you simply will not know what to expect. I also sat in for an MCAT earlier in 2011 and the BS was very similar to the AAMC exams with very few nasty surprises.

Good luck to all.

 

[Dreamer29]

Late to post, but thanks OP!

 

[OCDOCDOCD]

I have a hard time believing the bio passages would have that much jargon and inhibition/excitation steps thrown in. Not only does it make reading it almost impossible, but the sheer leap in difficulty is so great that not even TBR's bio passages come close to matching that, and I've heard that their passages still exceed the difficulty of what you'll find on the actual MCAT.

I could see the logic-based, concept heavy aspect of these questions being on the exam, but not in a manner that requires you to trudge through dense jargon just to have a chance at being able to utilize the concepts the question writers are trying to test.

 

[StilgarMD]

I have a hard time believing the bio passages would have that much jargon and inhibition/excitation steps thrown in. Not only does it make reading it almost impossible, but the sheer leap in difficulty is so great that not even TBR's bio passages come close to matching that, and I've heard that their passages still exceed the difficulty of what you'll find on the actual MCAT.

I could see the logic-based, concept heavy aspect of these questions being on the exam, but not in a manner that requires you to trudge through dense jargon just to have a chance at being able to utilize the concepts the question writers are trying to test.

given your name, i think you should be alright with believing this. the jargon isn't jargon, its stuff you should know like the back of your hand. shadow in a hospital and you'll notice those people buzz through a handful of acronyms in every sentence. its all about extracting data and making choices. what part of that passage do you think is jargon?

 

[OCDOCDOCD]

given your name, i think you should be alright with believing this. the jargon isn't jargon, its stuff you should know like the back of your hand. shadow in a hospital and you'll notice those people buzz through a handful of acronyms in every sentence. its all about extracting data and making choices. what part of that passage do you think is jargon?

Yes, I'm sure we're supposed to know what NF-kB, IL6, Lin28, STAT3, and let 7 are like the backs of our hands. Of course that isn't jargon, that's just common knowledge.

I work in a neuro lab, I live and breathe jargon, but the difference is that I wouldn't expect someone with only a knowledge of intro bio I and II to be able to parse any of it inside of 8 minutes. If OP's passage is representative, then it wouldn't be unreasonable to expect a passage on a basal ganglia circuit to pop up as a nervous system passage on the MCAT seeing as how it's at about the same level of complexity when it comes to the amount of jargon and tracking everything threw a half dozen or so excitation/inhibition interactions. However, that's sort of thing you put as a full page essay question on an upper level undergrad neuro exam or a med school's neurology final (in fact, one of my PI's put such a question on her neurology class's final and nearly everyone in the class bombed it).

 

[johnnydoesdat]

I have a hard time believing the bio passages would have that much jargon and inhibition/excitation steps thrown in. Not only does it make reading it almost impossible, but the sheer leap in difficulty is so great that not even TBR's bio passages come close to matching that, and I've heard that their passages still exceed the difficulty of what you'll find on the actual MCAT.

I could see the logic-based, concept heavy aspect of these questions being on the exam, but not in a manner that requires you to trudge through dense jargon just to have a chance at being able to utilize the concepts the question writers are trying to test.

+1
I feel the exact same way.

 

[apc]

Yes, I'm sure we're supposed to know what NF-kB, IL6, Lin28, STAT3, and let 7 are like the backs of our hands. Of course that isn't jargon, that's just common knowledge.

I work in a neuro lab, I live and breathe jargon, but the difference is that I wouldn't expect someone with only a knowledge of intro bio I and II to be able to parse any of it inside of 8 minutes. If OP's passage is representative, then it wouldn't be unreasonable to expect a passage on a basal ganglia circuit to pop up as a nervous system passage on the MCAT seeing as how it's at about the same level of complexity when it comes to the amount of jargon and tracking everything threw a half dozen or so excitation/inhibition interactions. However, that's sort of thing you put as a full page essay question on an upper level undergrad neuro exam or a med school's neurology final (in fact, one of my PI's put such a question on her neurology class's final and nearly everyone in the class bombed it).

if you go through some of the mcat threads, you'll see that most ppl have been surprised and mind fked by some of the bio passages.
this was very helpful, but i think actual mcat passages are a bit more clear.
outside knowledge helps, but you dont need to know the meaning of every term (certainly not like the back of your hand) in the passages to solve the questions. like most ppl say, its like solving a puzzle.
again, its more extracting data, than having familiarity with every possible topic

 

[OCDOCDOCD]

if you go through some of the mcat threads, you'll see that most ppl have been surprised and mind fked by some of the bio passages.
this was very helpful, but i think actual mcat passages are a bit more clear.
outside knowledge helps, but you dont need to know the meaning of every term (certainly not like the back of your hand) in the passages to solve the questions. like most ppl say, its like solving a puzzle.
again, its more extracting data, than having familiarity with every possible topic

Yeah, I've seen that, but I've also heard TPRH science workbook is pretty representative of the bio section, and that TBR is representative of the "out of left field" type of questions. This is just...not even remotely like anything in any of the practice materials out there. Now if it is the case that this is just like the real bio section on the MCAT and that, yes, no prep company or AAMC materials are representative of the real thing, then what's the point of even trying to study for the bio section? Certainly we would have heard opinions by now along the lines of "don't bother studying for BS, there's nothing out there remotely like it" or "best way to study for MCAT these days is to sign up to take a test, do it all, then void, and keep doing that until you feel ready" (after all, even if you did 7 "practice" tests like this it'd still be cheaper than a prep class).

On that note it would be helpful if someone who's actually taken the test can give their opinion on the matter instead of all of us just speculating.

 

[crazedpiggy]

I've taken the MCAT before and I was serious when I said that some MCAT passages on the real BS are similar. I remember having a passage regarding various experiments on mice to investigate the mechanisms of diabetes. The passage was cluttered with twenty graphs (no exaggeration) and questions I've never seen before.

Naturally, I panicked.

Yes, passages like this do exist. I'm not making this up to scare people. Honestly though, you can't expect to memorize your way through BS and expect to do well. The new BS is stressing analytical skills and being able to adapt and think on your feet more than ever.

 

[TXKnight]

Good post, this is very similar to how I work through experimental passages like this. I draw pathways while reading the text, not looking down on the paper; maybe legacy from my research years. I mostly end up doing great on complex experimental questions. Now, one caveat is, MCAT likes simple stuff presented in convoluted ways, therefore go easy on your pathways or whatever visual means you use, if you go too detailed then you run the risk of running out of time. I happened to me during practice tests, but not on the real one.

 

[TipToad]

This is just...not even remotely like anything in any of the practice materials out there. Now if it is the case that this is just like the real bio section on the MCAT and that, yes, no prep company or AAMC materials are representative of the real thing, then what's the point of even trying to study for the bio section?

Took the 5/24 test. I can safely say the BS section is nothing like the AAMC or Kaplan or EK. Can't speak for TBR or TPR, but I hear they aren't too good, either. Got straight 13's on the last 5 AAMC BS sections. Left the real MCAT BS wanting to kill myself.

My biology background includes genetics, physiology, adv cell bio, adv biochem, microbio, and biochem research, and I thought the real BS was hard as ****, jargon and all.

 

[nabilesmail]

I wrote one for fun too! Maybe if we all write some of these we can all help each other out =]

Children with the inherited disorder Fraser syndrome suffer from severe, often fatal, birth defects. Mutations in four genes trigger the syndrome. Three of these genes encode proteins, including QBRICK, that localize to the basement membrane between an organ's outer epithelial cells and the mesenchymal cells beneath. During development of an organ such as the kidney, epithelial and mesenchymal cells interact with the basement membrane, and without this interplay the organ can't form properly. For mesenchymal cells, the &#945;8&#946;1 integrin serves as the basement membrane receptor.

Kiyozumi et al. tested whether QBRICK is the binding partner of the &#945;8&#946;1 integrin. Mouse embryos that lacked QBRICK showed reduced binding between the &#945;8&#946;1 integrin and the basement membrane, suggesting that QBRICK and the integrin interlock. However, rodents that carried a version of QBRICK that can't latch onto the integrin were healthy and had normal &#945;8&#946;1 integrin binding, indicating that a direct interaction between the two proteins isn't necessary for development. Instead, the researchers found, QBRICK helps anchor another basement membrane protein, nephronectin, which connects to &#945;8&#946;1 integrin and promotes interactions between mesenchymal cells and the basement membrane.

Mice lacking QBRICK produce normal amounts of nephronectin. But the researchers suspect that without QBRICK to detain them in the basement membrane, the nephronectin molecules become unstable and are destroyed.

1) It was discovered that a mouse embryo held a recessively expressed mutation of the Nephronectin gene. How would this affect kidney development in a normal QBRICK expressing embryo?
A) kidney development would not continue unless nephronectin supplement was consumed.
B) a8B1 Integrin would no longer be able to bind QBRICK Product resulting in failed kidney development.
C) Basement membrane interactions would cease resulting in impaired kidney development.
D) Nephronectin would react normally with QBRICK product resulting in normal kidney development.


and then I got tired lol. Man being an MCAT test writer sucks, heres 1 question for yall!

Answer C

 

[apc]

Yeah, I've seen that, but I've also heard TPRH science workbook is pretty representative of the bio section, and that TBR is representative of the "out of left field" type of questions. This is just...not even remotely like anything in any of the practice materials out there. Now if it is the case that this is just like the real bio section on the MCAT and that, yes, no prep company or AAMC materials are representative of the real thing, then what's the point of even trying to study for the bio section? Certainly we would have heard opinions by now along the lines of "don't bother studying for BS, there's nothing out there remotely like it" or "best way to study for MCAT these days is to sign up to take a test, do it all, then void, and keep doing that until you feel ready" (after all, even if you did 7 "practice" tests like this it'd still be cheaper than a prep class).

On that note it would be helpful if someone who's actually taken the test can give their opinion on the matter instead of all of us just speculating.

im a retaker. and that was my opinion.
as for the bolded part, you have do yourself a favor and go through the 5/24 thread. read some of the initial responses. some ppl match your quote word for word.
tbh, i find it very difficult to prepare for the bs. not b/c its hard, but b/c there isn't enough practice material out there. anyways, aamc practice exams are similar to the actual mcat, but there will be 2-3 passages that are just out there, and those are the ones you cant really prep for.

 

[apc]

I've taken the MCAT before and I was serious when I said that some MCAT passages on the real BS are similar. I remember having a passage regarding various experiments on mice to investigate the mechanisms of diabetes. The passage was cluttered with twenty graphs (no exaggeration) and questions I've never seen before.

Naturally, I panicked.

Yes, passages like this do exist. I'm not making this up to scare people. Honestly though, you can't expect to memorize your way through BS and expect to do well. The new BS is stressing analytical skills and being able to adapt and think on your feet more than ever.

haha 9/2?
thats the one i had. i spent around 13 minutes on that passages alone. to top it off, there were 2 or 3 ochem passages following that passage. and here i am, getting ready to take it again

 

[crazedpiggy]

haha 9/2?
thats the one i had. i spent around 13 minutes on that passages alone. to top it off, there were 2 or 3 ochem passages following that passage. and here i am, getting ready to take it again

Hah, yeah - I'm in the same exact shoes as yours. Had the BS section went more like the AAMC's I wouldn't be here right now.

Also man, those orgo questions from 9/2... I specifically remember at least two questions where they only gave us systematic names for all reactants and then made us predict the products where the names were all given as systematic names as well. Talk about time consuming, especially on top of that diabetes passage.

Anyways, best of luck to both of us

 

[StilgarMD]

Yes, I'm sure we're supposed to know what NF-kB, IL6, Lin28, STAT3, and let 7 are like the backs of our hands. Of course that isn't jargon, that's just common knowledge.

as long as you know what miRNA are, you could replace everyone of those names with a Letter and easily get the answer. to me, Jargon is only an obstacle if its complete understanding is demanded of the passage. these mol bio pathways seem more like logical puzzles to me.

 

[apc]

Hah, yeah - I'm in the same exact shoes as yours. Had the BS section went more like the AAMC's I wouldn't be here right now.

Also man, those orgo questions from 9/2... I specifically remember at least two questions where they only gave us systematic names for all reactants and then made us predict the products where the names were all given as systematic names as well. Talk about time consuming, especially on top of that diabetes passage.

Anyways, best of luck to both of us

i know. i dont even know how i finished on time. i guessed on so many after that passage. best of luck

 

[WorriedDO]

I read this post about 5 days before I took the mcat(5/19). This little passage is a far better representation of mcat Bio than anything I've come across. This and ebola from AAMC 11.

 

[OCDOCDOCD]

as long as you know what miRNA are, you could replace everyone of those names with a Letter and easily get the answer. to me, Jargon is only an obstacle if its complete understanding is demanded of the passage. these mol bio pathways seem more like logical puzzles to me.

Yeah, no, you're right. I actually gave OP's question a decent try this time and it made a lot more sense. It's actually pretty easy once you get past the jargon and write down the pathway.

That's not stopping me from freaking out after reading this thread though. I'd like to think I'd be good at critical thinking heavy passages on account of the fact that I've been doing research for five years, but at the same time I pretty much neglected everything in biology that didn't have to do with neurons the day I finished intro bio II so my molecular bio and genetics is pretty weak. I do well enough on AAMCs (so far, only done #3-5) and TPRH, but if the real exam throws me molecular bio curve balls like this....well, it's back to being pre-grad. Even if the questions are in reality pretty easy, I'll probably be too busy curling into the fetal position to realize it.

 

[ridethecliche]

I just took the MCAT and I think that the OP's advice is GOLD.

When you see a passage in bio that involves anything that is a pathway, you should diagram it out yourself.

This is essential. Why? Because if you don't, you're going to go around in circles trying to put the info together from the passage. You'll lose time and freak yourself out.

Read actively, esp for bio. I would suggest that you read the questions, then quickly skim of the passage to figure out what's going on, then read actively and diagram/nit pick. This way you pay attention to what's being asked of you and have a diagram to refer to when you go back to doing the questions.

This is not verbal, it doesn't take that long to read it.

I honestly wish I had figured this out before my test. I'm a little terrified at what the outcome of my exam is going to be.