Official SAT Subject Test - Biology E/M - June 2015

@xxjmodxx If i remember correctly, it was together, apart, then together again. Can anyone second that?

@AmericanGothic ok. So for your first question, I am pretty sure I also chose the one with 3 differences because if that was the gene where the humans showed the most difference (the others were 0 differences and 1 difference). For the second one I also said the same thing as you did, measuring for 1 square mile and then extrapolating. The question about the slopes I also said something about faster evaporation but I completely guessed on this one so I am hoping it is right (Do you know if it is right). Lastly, I also said the first answer is substrate composition (I am 95% sure it is). For the other question, I don’t know if it was seeing if they were 2 species but maybe just comparing them because I don’t think there was a choice that said something about interbreeding. I said DNA evidence though.

@TalkTheTalk Ya I said that too

Does anyone know the answer for the pine tree one? Was it about faster evaporation?

For M does anybody remeber the percent of pink flowers and dwarfs? They were two seperate ones… Not the 1/16 and 0

It was compare DNA samples for the two species right? Saying watch their behavior is kind of vague

Okay so no one can seem to remember. For one of them the answer was inversion because the order of the nucelotides got reversed but another question asked about a gene that is inherited over time but also some organisms just have it or something like that. It also said that this gene was not linked. It gave choices like deletion, substitution, inversion, and others. I was between deletion and substitution; what did you guys get?

@xxjmodxx Wasn’t duplication a choice? Didn’t it say that the two chromosomes both had similar genes or something?

I guess

Does a 76.25 round up to a 77 or is it a 76?

@theflash123 it’s a 76

Ok. So 3 wrong is no longer an 800? @normanxi

@theflash123 did you not see the link I posted to the scoring guide? 3 wrong has never been 800…it’s 3 wrong without the guessing penalty. If you get 3 wrong, it’s 77-(3/4)=76.25, rounds to 76, and is a 790. If the 3 you got wrong are the ones you omitted, THEN you could get an 800

There is some dissent over the spindle fibers question. It stated if spindle fibers couldn’t form which phase of mitosis would be affected. Spindle fibers are made during pro-phase but they are most important during anaphase when the chromosomes are brought to the opposite sides. Thus, it becomes confusing whether the question is testing your knowledge of when they are formed or when they are most active. In prophase the spindle fibers are the product and in anaphase they are the means. Considering all this, and the fact that the question asked which phase would be affected if they didn’t form, I feel anaphase would be most influenced depsite their formation being a product of prophase. What do you guys think?

@xxjmodxx It’s absolutely anaphase. I didn’t think it was that unclear; it was just testing to make sure you not only knew the stages of mitosis/meiosis but also the specifics of them. Nothing is actually INHIBITED until metaphase (despite the fact that the spindles haven’t formed when they should have), when the spindle fibers assist in bringing chromosomes to the metaphase plate. However, because metaphase wasn’t an option, the next phase is the answer because it also requires the spindle to separate chromatids, and without spindles this cannot happen.

@theflash123 Not sure if the pine tree one is really faster evaporation, but I think it makes the best sense (there’re also other guys who concur).

The question about the two species was like (I remember and am pretty sure that the question stated like this) “how to prove that the two populations in fact represent two different species”. None of the answer choices said “interbreeding”. The one I chose was like “Relocate some to a new marsh”… which can possibly cause interbreeding. I went a step further from what was said in the answer choice (I wasn’t willing to do this, but I didn’t think any of the other choices made sense) and inferred that if some are relocated, researchers can see if they can interbreed, thus to know if they are different species…

@AmericanGothic it is substrate composition

@Boltingflame That question was “how to prove the two populations were in fact two different species”. Answer choices include: compare their behavior, compare their DNA, compare their embryology, relocate some to a new marsh, and another choice I can’t remember. I said “relocate some to a new marsh”, because I thought doing so allows researchers to see if these two populations can interbreed and produce fertile offspring.

@RybkaShredder Yeah I know. I was referring to the question after the substrate one.

@CollageWhat I don’t think it’s safe to say that 3 wrong has never been an 800. The blue book scoring guide corresponds specifically to the particular one test provided in the book. For other editions of the biology E/M there must be different score conversion tables. And I think the administration we took on June 6 was actually harder than the one in the blue book (although I think I got fewer questions wrong on June 6 than I did on the blue book test). So 3 wrong might still be an 800, depending on how TCB evaluates the difficulty of this test and how lucky we are.