AP Biology 2011 Official Thread

Test Preparation AP Sciences
861

<p>1A) I mentioned mitochondria, ribosomes, endoplasmic reticulum, nucleus, and lysosomes and their respective functions.</p>

<p>1B) I chose mitochondria (prokaryotes carry out the function of the mitochondria in their plasma membrane), nucleus/ER, and lysosomes.</p>

<p>1C) I basically said that mitochondria have their own DNA, are membrane-bound, and are about the same size as prokaryotes.</p>

<p>2A) I used the jellyfish as an example of intracellular digestion and a worm as extracellular digestion. Not too sure about jellyfish being an intracellular digestion example.</p>

<p>2B) I said the stomach mechaniclally turns the food it holds into chyme with the help of hydrochloric acid and i mentioned pepsinogen –> pepsin –> protein breakdown. I was able to do more for the small intestine; the long lenght of it and the villi/microvilli/lacteals increase the surface area of the small intestine and help it perform its primary function: absorption of nutrients.</p>

<p>2C) Stomata for gas exchange/regulation in plants; xylem/phloem for water and nutrient transport; roots and root hairs for water absorption and increased surface area for water absorption.</p>

<p>3A) Binary fission of bacteria. One advantage is that it’s suitable for unstable environments, another being it costs less time and energy to the parent in both the reproduction itself and the fact that no mate has to be found.</p>

<p>3B) I mentioned synapsis, crossing over, independent assortment and one more way i can’t recall right now.</p>

<p>3C) Mechanical isolation: a fly and a human can’t mate because of reproductive structure differences. Behavioral isolation: some animals have complex mating rituals to protect themselves from predators as well as assuring that their mate is of the same species, fertile, and healthy, and thereby increasing the chance of healthy offspring. </p>

<p>4A) I calculated the rates to be .14 and .24.</p>

<p>4B) I mentioned a difference in cuticles, stomata, plant type, lenticles.</p>

<p>4C) I guessed that the “p” and “s” of the first equation are pressure and solute concentration. The second equation was even more of a guess; no clue what the “-i” represents, the “C”, “T”, “R” i put as concentration of solute, temperature of solution, and rate of osmosis, respectively. </p>

<p>For pretty much all of my answers, I tried to give more information than needed… just in case.</p>

862

<p>Hey check this out, I got it from Lab Bench: (I studied this, but we got another set of FRQs - my hard luck)</p>

<p>Solute potential = –iCRT</p>

<p>i = The number of particles the molecule will make in water; for NaCl this would be 2; for sucrose or glucose, this number is 1
C = Molar concentration (from your experimental data)
R = Pressure constant = 0.0831 liter bar/mole K
T = Temperature in degrees Kelvin = 273 + °C of solution </p>

<p>Here is the link:
[url=&lt;a href=“Prentice Hall Retirement – PHSchool – PHSchool.com – Savvas”&gt;Prentice Hall Retirement – PHSchool – PHSchool.com – Savvas]LabBench[/url</a>]</p>

863

<p>The thing is that if it said list two advantages, they are only going to grade the first two they read.</p>

<p>Sent from my PC36100 using CC App</p>

864

<p>Wow, I guessed what i, C, R, and T were based on what I learned in chemistry 2 years ago. I got all the variables right.</p>

865

<p>i thought it was </p>

<p>pi (osmotic) = iMRT </p>

<p>M is molarity
i is van’t hoff
R is constant
T is in kelvin</p>

866

<p>Just looked at the FRQs now that they’ve been posted. I want to say that this year’s are substantially more difficult than last year’s… I’m not sure I would’ve got a 5 last year if these were my questions. </p>

<p>Congratulations to anybody who achieves a 5… honestly. :cool:</p>

867

<p>aren’t there supposed to be the same percent of 5’s each year?</p>

<p>so you should have gotten a 5 this year too</p>

868

<p>Nope. If you look at the past years’ distributions, they have the ability to fluctuate by almost a whole percentage point: [Advanced</a> Placement Biology - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Advanced_Placement_Biology]Advanced”>AP Biology - Wikipedia)</p>

<p>Not sure if that’s statistically significant though. My point is I wouldn’t have been able to do as well on those questions and would’ve received probably a four.</p>

869

<p>A) I mentioned mitochondria, ribosomes, nucleus, and lysosomes and their respective functions.</p>

<p>1B) I chose mitochondria (prokaryotes carry out the function of the mitochondria in their plasma membrane), ribosomes, and nucleus.</p>

<p>1C) I basically said that mitochondria have their own DNA, are membrane-bound, and are about the same size as prokaryotes. Also mentioned chloroplasts, membrane bound, DNA, ribosomes, and cyanobacteria comparison</p>

<p>2A) starfish for intracellular and fungi for extracellular? (bs’d that)</p>

<p>2B) Pyloric sphincter as a muscular structure that will prevent food that is not yet fully prepared for small intestine and other things from entering small intestine. Villi and microvilli of small intestine to increase the surface area of the small intestine for nutrient absorption</p>

<p>2C) xylem/phloem for water and nutrient transport; roots and root hairs for water absorption and increased surface area for water absorption, and diffusion allowing nutrients to also enter root.</p>

<p>3A) Binary fission of bacteria. Dependent only on single parent (not worried about isolations)</p>

<p>3B) Crossing over, sexual selection (choosing best mate), and outbreeding vs inbreeding increases genetic variability</p>

<p>3C) Mechanical isolation: a penguin and a human can’t mate because of difference in genitalia structure. Geographic isolation: if in different environments or different places, then separated (sugar glider in Australia can’t mate with flying squirrel of N. America bc of a bigggg body of water)</p>

<p>4A) i honestly cannot remember but I rounded a bit</p>

<p>4B) I mentioned a difference in cuticles, CAM (vacuole storage of malate) and C4 (bundle sheath)</p>

<p>4C) I completely guessed</p>

870

<p>Is binary fission in bacteria a specific example? </p>

<p>For 4B, would a thinner xylem account for faster transpiration due to the increased capillary action, thus, speeding up the whole system?</p>

<p>At this point I think its no use stressing anymore, lets just wait till July 1, no more CC for me. Every time I get on, I end up finding another mistake I made.</p>

871

<p>Yeah…so may I take the liberty of declaring this thread dead until July 1st?</p>

872

<p>Please do so… and pray to the AP Bio gods for a 5.:)</p>

873

<p><em>prays</em></p>

<p>10char</p>

874

<p>Since the curve can fluctuate by about 5%, I’m guessing the composite to get a 5 is 106.5…(as opposed to AP Pass’s 95) just throwing that out there ;)</p>

875

<p>^Why do you say that? The AP Pass curve reflects the estimate that College Board itself made to cope for the lack of a guessing penalty, and I didn’t think the FRQs were THAT easy…</p>

876

<p>I agree, the free response questions covered a lab that most classes don’t get to, and also topics such as specific organismal biology, which is PURE memorization. I didn’t think they were easy at all…</p>

877

<p>Well, most generally agree that most of it was WAY easy, besides the last water potential equasion. I just think it might fluctuate by that 5% not to adjust to the no guessing penalty but to how easy it was…</p>

<p>and the MC was incredibly easy too, even people you’d think get 1’s in my class felt ok about the whole thing, along with the FRQs</p>

878

<p>I think that there were several multiple choice questions which were quite challenging, and I don’t think that the FRQs were as easy as people are making them out to be. With regards to Khaum, many people in my class who you’d think get 1’s felt okay about it. Here’s my thoughts, those who didn’t study at all and took no interest in the class didn’t understand the complexities behind the questions. </p>

<p>Say I gave you guys a question. What is Photosynthesis?
All of us would break out into a lengthy discussion about the light dependent reactions…photsystem I, Photosystem II, etc. And then into the Calvin Cycle. </p>

<p>Somebody else (who wasn’t well versed in biology, blew off the class) would answer: How plants make food!
THAT WAS EASY!</p>

<p>Hope I just made sense.</p>

879

<p>Yes, that’s true! I might just be paranoid, but I still think it was much easier than most were expecting…I mean, on the MC I did just have to guess on three but the rest was just…easy. But I see what you’re saying and I hope that’s the case :)</p>

880

<p>@dylandlima</p>

<p>Exactly! And the thing is, if “those” people think its easy (sounds so cynical), then how harsh will the curve be for somebody to get a 5! I mean, there still will be about 20% of the entire population of test takers who get a 1, and I’m just worried because even those 20% think they did well? Then how well do we need to do in order to get a 5?! </p>

<p>That’s my worrying thought of the day. Time to study for the Bio SAT II… :/</p>