<p>uhh so I took the ap bio practice exam on sparknotes and got a 102 out of 150 for raw score… 37 correct 13 incorrect 0 guessed. It said I got a 5</p>
<p>So my question is, how difficult is the real ap exam compared to the sparknote practice exam? Thanks :)</p>
<p>Edit: Sorry if I sounded rude with my question >_> I pulled an all-nighter to go over half of the material… I can’t even formulate a sentence correctly atm :/</p>
<p>■■■ ■■■ ■■■ ■■■. i’ve barely studied. i have all of today to finish cliffs and the practice tests in it. it’s 7:53 a.m. and i’m pretty much gonna need to do bio until i go to sleep tonight…SICKKK not</p>
<p>i also predict dna replication. That is a huge process and it hasnt been an essay topic for the past almost 10 years.</p>
<p>Do any of you have essay predictions for Monday’s Exam?</p>
<p>chi-square:</p>
<p>It’s about drosophila lab right? So we are basically checking weather the outcome result of the lab “fits” well into the expected results.</p>
<p>The chi-square equation is : Sum of (Observed-Expected)^2 / Expected</p>
<p>degree of freedom is K-1, which is column - 1.</p>
<p>So let’s suppose we produced our f2 generation. We crossed Bb x Bb 1000 times, which B is black and b is brown. The actual outcome was black: 800, brown: 200. at the 10% significance level, does this outcome support our assumptions?</p>
<p>H0: chi-square fits well yeah!
Ha: It doesn’t fit well :(</p>
<p>possible genotypes of Black are BB, Bb. If we make monohybrid cross between above two traits, we should get BB, Bb, Bb, bb. Since there are three blacks, (BB, Bb, Bb), the probability of getting black is 3/4 = 0.75, and probability of getting brown is 1/4 = .25</p>
<p>The expected values will be then multiplying those probabilities with the N, which is 1000. Then we should’ve got (according to the probability) 750 blacks and 250 bronws.</p>
<p>Black: observed-800///////expected-750 (800-750)^2/(750)
brown: observed-200//////expected-250 (200-250)^2/(250)</p>
<p>add those two results up, then we get 10+3.3333 = 10.3333 as a chi-squre test statistics.</p>
<p>Degrees of freedom here is (black and brown = 2) - 1, so it should be 1.</p>
<p>AP biology test makers would give you a chart that shows corresponding chi-square values for certain signifcance level. Then, just compare the obtained chi-square result with the one that shows up on the chart. If the obtained result is bigger, that means there is lower probability of rejecting H0, so we say “at the 10% significance level, there is not enough evidence to reject H0, blah blah”</p>
<p>But if the obtained result (13.333) is smaller, then there is higher probability to “reject H0”. Meaning that, we say “At 10% significance level, there is enough evidence to reject Ho, blah blah”</p>
<p>-Thank God I took ap stat course.</p>
<p>If i made any mistake, please correct it :)</p>
<p>^ excellent…thanks.</p>
<p>I predicting the FRQs will be:</p>
<ul>
<li>something on digestion</li>
<li>something on feedback mechanisms</li>
<li>some lab / experiment question</li>
<li>some ecology question</li>
</ul>
<p>Anyone else got some predictions?</p>
<p>With the exception of the lab question, your other three predictions are all in the same unit (Organisms and Populations) so they won’t be asking all three.</p>
<p>They pick one from each unit: Molecules and Cells, Genetics and Evolution, Organisms and Populations, and then a lab question.</p>
<p>
</p>
<p>Chi-square has already shown up as a topic in one of the previous FRQs. So, I doubt it will show up again.</p>
<p>I should know this - that specific FRQ showed up in one of our class tests. </p>
<p>DNA Replication - interesting. I think I should go over that.</p>
<p>Does anyone know a quick way/tricks to find out whether a particular trait is autosomal (recessive/dominant) or sex-linked (recessive/autosomal) from a pedigree chart? </p>
<p>I spend a lot of time on those - analyzing every possibility and I still end up getting it wrong.</p>
<p>hey, does anyone have a good video on DNA replication? and/or transcription and translation? if that is a frq… then i need some review!! thanks</p>
<p>@xxrunning: If quite a few males AND females have the trait, it’s probably not sex-linked. Sex-linked recessive traits are seen more often in males since they are carried on the X chromosome. </p>
<p>If you see that of two parents, neither of them express the trait, but one of their children does, then you can assume that the mom was possibly a carrier (you’d have to look at her parents to find out) and again, it may be a sex-linked trait.</p>
<p>If you can find an example of a pedigree chart, one for autosomal and one for sex-linked, I’ll be glad to list my thought process for you so you can see how it can be determined.</p>
<p>@hellohellicopter: Check out chapter 11: <a href=“http://bcs.whfreeman.com/thelifewire/content/chp00/00020.html[/url]”>http://bcs.whfreeman.com/thelifewire/content/chp00/00020.html</a></p>
<p>^ I have a question. Are there any traits that are sex-linked on the Y chromosome?</p>
<br>
<br>
<p>Im thinking DNA replication- describe the role of the following in DNA replication:
DNA polymerase (1 and 3)
Ligase
Helicase
Primase
ATP </p>
<p>I also think enzyme lab or osmosis lab (they havent done osmosis for a very long time)</p>
<p>The immune system (my teacher predicted this-he said they told him at a conference to stress it like a few years ago)</p>
<p>Really? hmm… that makes sense. Anyways I hope they pick one of my three non-lab predictions. I know those perfectly. </p>
<p>Anyone know how important classification is?</p>
<p>EDIT: i thought they did a immune system question a few years ago, and same with DNA replication. I’ll still review both though.</p>
<p>they did immune system like 5 years ago but they could repeat. Theyve done dissolved oxygen in 3 of the last two years’ tests including 2008 form a and b lol. They havent done dna replication in a solo essay in the past 10 years at least i think.</p>
<p>
Other than hairy ears, I can’t think of any. LOL The y-chromosome hardly has any traits on it anyways. Just know that sex-linked traits are carried on the X chromosome 99.9999% of the time. :)</p>
<p>I think the FRQ will include the fruit fly lab or Hardy</p>
<p>^ I hope so… that’s easy! :p</p>
<p>There is male-pattern baldness on the Y-chromosome, I believe. Otherwise, things such as Turner’s syndrome come to mind when I think of non-X-linked disorders.</p>