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Re: Biology Questions

Posted: Tue Apr 17, 2018 6:51 pm
by NS_Tutor_Andrew
MCAT_Retaker,

Yes, both because your answers are correct and because I believe that this question should refer to the structure of a nucleosome, not of a histone core. Thanks for pointing it out! The coding of the correct answer choice should at least be a quick fix. I hate to ask a follow-up question, but would you mind letting me know which video this is in? Thanks!

Re: Biology Questions

Posted: Thu Apr 19, 2018 6:04 pm
by MCAT_Retaker
Chromosome Organization video!

Re: Biology Questions

Posted: Fri Apr 20, 2018 3:13 pm
by NS_Tutor_Andrew
Thank you, and duly noted!

Re: Biology Questions

Posted: Fri Apr 20, 2018 5:15 pm
by MCAT_Retaker
another mistake?

Re: Biology Questions

Posted: Fri Apr 20, 2018 6:55 pm
by MCAT_Retaker
Can you explain?

Re: Biology Questions

Posted: Fri Apr 20, 2018 9:21 pm
by MCAT_Retaker
I thought cerebral is not mediated by SNS?

Re: Biology Questions

Posted: Fri Apr 20, 2018 10:34 pm
by MCAT_Retaker
can you explain. such a basic concept :/

Re: Biology Questions

Posted: Mon Apr 23, 2018 2:57 pm
by NS_Tutor_Andrew
Hi MCAT_Retaker,

Re: electrophoresis, the inclusion of "Item 4" is definitely a data entry error that needs to be fixed.

Re: blotting, the statement you checked off is wrong in a couple ways. Antigen-antibody interactions are used in western blotting, but not in other forms of blotting (Southern blotting is for DNA & northern blotting is for RNA, and antigens/antibodies only apply to proteins), so that statement doesn't answer the question. Also, even when limited to western blotting, it wouldn't quite be correct to say that antigens are used to GENERATE antibodies...I mean, that's true in general but it's not like western blotting in reality is performed by letting B cells do their thing in the sample you're preparing. That is, antibody generation isn't really part of the blotting process itself, it's more of a prerequisite step.

For cerebral perfusion of the SNS, evidence varies -- an older article suggests that the SNS does regulate cerebral blood flow, but a more recent review suggests the opposite. From a scientific point of view, I'd be inclined to trust the more recent review, so we'll need to revise that question. Practically speaking, I have not often seen the MCAT test this aspect of the SNS one way or the other with any real frequency.

Finally, you answered the question on serotonin correctly, but the answer is coded incorrectly (another data entry error to fix). The idea is that you can promote the presence of serotonin in the synapse by either not letting it be taken back up (inhibiting the reuptake) or by not letting it be degraded.

Hope this helps, & thank you very much for the questions!

Re: Biology Questions

Posted: Tue May 15, 2018 5:24 pm
by MCAT_Retaker
How do you distinguish between negative and anode, cant they be interhcangable? this is from lesson 7.

Re: Biology Questions

Posted: Wed May 16, 2018 11:34 pm
by MCAT_Retaker
Can you please draw it out for this question


i took a stab at it


Is this correct

n=nucleus

n........n (diploid)
n,n........n,n Nucleus duplication

2n,2n....2n,2n DNA replication

4n,4n...4n,4n DNA replication again