Hello,

Passage 3, q.1 in AAMC physical sciences section bank asks us to identify a molecule and its name. It is a modification to a phospholipid with a nitrogenous group attached to the phosphate head. The molecule is called a phosphatide.

Is there a list of molecule names we should be memorizing? I don't think I would have been able to answer this question without memorizing the functional groups present in a phosphatide. Is there anyway I could have come to the conclusion based on reasoning vs. memorization?

Thank you

For the physical sciences section bank AAMC - q. 2 asks us tp identify the reaction that lead to the product within the passage. The answer is the carboxylation of hydroquinone. Hydroquinone is not discussed within the passage, so to answer this question I would most likely need to have memorized the structure of this molecule - is this need to know for MCAT?
Is there another way I could have intuitively answered this question? I thought the answer would be a oxidation reaction due to the abundance of oxygen bonds in the product shown in the passage.

Thank you:)

Hello,

Altius COVID 4 question 29 is an application of the ideal gas law - however, looking at the Altius solution, I don't think I would be able to finish this question and would probably mark it and move on. In class, Mike taught us to use STP parameters to make our PV=nRT equations a bit easier. Would Mike's method work with this question? If it can, could you please walk me through it?

Thank you

Hello,

One of the flashcard question from the physics AAMC questions states:

"Suppose a certain far-sighted person can see objects clearly no closer than 300 cm away. What is the minimum distance from a plane mirror such a person must be to see his reflection clearly?"

We never really discussed plane mirrors - could someone please explain to me why this distance would be halfed?

Hello,

In the Altius 3 COVID exam, passage #2, question 7 - I have a few clarifying questions.

The question is asking about the dissolution of the same mass solids in some solvent, and their respective ratios.

The chemical equation in question is as follows:

4Ca5(PO4)3F(s) + 18SiO2(s) + 30C(s) --> 3P4(g) + 30CO(g) + 18CaSio3(s) + 2CaF2(s).
The question asks if 12.5 g of each of the solids produced in this reaction were combined with 1.7L of water and stirred until no further dissolution occured, which relationship would be true of the resulting solution?

The answer is that the concentration of Ca2+ would be greater than the concentration of SiO32-.

For this answer, I'm wondering if it is as easy as seeing that there is more calcium in our products than SiO3? Or is there some math involved? I think what through me off was the stoichiometric coefficients and how to account for them when we were dissolving in a solvent.

Thank you

That's very helpful thank you so much! One follow up: why did you use the equation pi(r^2)x L for the volume?

Hi,

Sorry I'm not sure how to link to the question, but it is question 30 in the Biology section Bank. I can copy the question here - there is no associated images or diagrams:

"In a species of beetle, red body color is dominant to brown. Two red beetles are crossed and produce 31 red and 9 brown offspring (F1 generation). If two red F1 beetles are crossed, what is the probability that both red and brown beetles will appear in the F2 generation? (Note: Assume Mendelian inheritance patterns.)"

I don't think any of the genotypes are lethal as this is not stated in the question stem. Any help in answering this would be appreciated, if you use a punnette square would you mind showing how you set up your punnette square?

Hello,

Thank you for getting back to me. I understand those genotypic ratios but for some reason am still lacking the logic to generate a 2/3 ratio for the probability both were heterozygotes in the F1 generation? Isn't this probability, based on mendillian genetics, 1/2 if you do a Rr x Rr cross?

Hello,

Thank you so much for your response. I think I better understand this question now. Would you mind further explaining question 54 and how this is making glucose a better leaving group. Would you be able to draw this out for me?

Thank you in advance.

Hello,

I have a question pertaining to the Physical Sciences section on the Altius #2 COVID Exam. It is attached to a passage but doesn't require any information from the passage as it is given in the question stem.

This question asks how decreasing the length by 50% and increasing the radius by 100% will affect the number of moles in a new concentration vs. an original concentration. At first glance this is a chem question regarding the idea gas law, but as you look through the Altius solution, it looks like they are applying some physics principles. For example: as you increase the radius by a certain factor, you increase the pressure by that factor, and as you decrease length by a certain factor, you increase volume flow rate by that factor.

Can I approach this question like this? Using this method, I am having difficulty mathematically coming to the ration that they did to find the answer. Should I stick to the ideal gas law? In addition could you please explain how they found increases of a factor of 5 and 2?

Thank you in advance.