<p>The null hypothesis is what you are trying to DISprove by carrying out your chi square analysis. In other words, by performing a chi square test, you are hoping to determine that the results you gathered in your experiment were not due to chance, and some outside factors were involved. Your p-value gives you the probability that your data values was obtained by chance alone. So if you had a p value of .01, that basically means 1% of trials conducted identically to yours would result in the same deviation from what is expected through chance alone. Since that is pretty low, we can conclude that there PROBABLY was some outside factor involved.</p>
<p>On the FRQ question, we were trying to determine if the presence of the cotton balls influenced the uneven distribution of the bugs, or was the uneven distribution due to chance alone. Now common sense tells us that the sugary ball would affect the distribution, but we need to carry out the chi-square to confirm this.</p>
<p>First we develop our null hypothesis. Remember, we are trying to DISPROVE this, so our null hypothesis would be that the presence of the balls has no impact on bug distribution, or something to that affect. If the balls really had no impact, we would expect, after 10 minutes, for the bugs to be concentrated as they were initially. This is why I used the 1 minute values for my expected. Some people were saying they went 20-20-20, but I don’t agree with that. Saying they were evenly distributed implies that there was an equal chance of them being found anywhere in the chamber. This isn’t true because the central bridge is much smaller than the two dishes, so it is less likely for a bug to be randomly found there. So I believe they wanted you to use the 1 minute values for expected. However, they did tell you to develop your own chi square test, so they might still accept 20-20-20, and, at any rate, your final results will still be the same.</p>
<p>So when we successfully perform and analyze the chi square test, we get a p value that is less than .01, if I recall correctly. This tells us that the chance of obtain results that deviated as far from the expected as ours did by chance alone is pretty freaking slim, meaning there had to be some outside factors in play. Obviously, this would be the cotton balls, so we can disprove our null and conclude the presence of a sugary ball does affect distribution. :)</p>
<p>So…did anyone else think that there wasn’t much to write for the short response, especially the last one?!</p>
<p>BTY, I’m also gonna take the SAT 2 in June…any advice on how to study?</p>
<p>Hello~
Does anyone know if the multiple choice and grid-ins are going to be released anytime soon online? I’m taking the late test (school opted for it due to Hurricane Sandy) on next Friday so I was thinking if I could look over those as part of the preparation… Thanks.</p>
<p>I haven’t been on much but, are most people saying the test was very hard? Would this mean the curve is most likely going down? Sorry if this has been asked a million times!</p>
<p>@chocolate339 college board hardly releases multiple choice to the public. Especially this soon after the ap test. However, the free response prompts will be released tomorrow, so you can refer to those in preparation</p>
<p>A few things.
First, question #2 part b. on FR.</p>
<ol>
<li>b) QUESTION
In an experiment, identical organisms containing the pigment from Graph II as the predominant lightcapturing pigment are separated into three groups. The organisms in each group are illuminated with light
of a single wavelength (650 nm for the first group, 550 nm for the second group, and 430 nm for the
third group). The three light sources are of equal intensity, and all organisms are illuminated for equal
lengths of time. Predict the relative rate of photosynthesis in each of the three groups. Justify your
predictions.</li>
</ol>
<p>High photosynthesis for green wave length (550 nm) and less photosynthesis for too big and too small wavelengths consisting of red (650 nm) and blue/violet (430 nm) respectively.</p>
<p>Also, in question 4.
Was Process 1 Photosynthesis and Process 2 Respiration? What organism does both? Is tulips a correct answer?</p>
<p>And for part C in FRQ #1. (Question is below for reference.)</p>
<p>(c) Bacteriorhodopsin has been found in aquatic organisms whose ancestors existed before the ancestors of
plants evolved in the same environment. Propose a possible evolutionary history of plants that could have
resulted in a predominant photosynthetic system that uses only some of the colors of the visible light
spectrum.</p>
<p>Adaptation by surviving efficiently on a few colors of light is better than being less efficient in photosynthesis on a wide variety of colors of light. Survival of the fittest through evolutionary adaptation helped many of these plants evolve to their current state. Is that answer sufficient? Thanks</p>
<p>I was wondering if we were allowed to discuss the FRQs with our AP Bio teachers? I want to ask my teacher what she thought the Z cell in one of the FRQs was (I put that jt was a red blood cell), because I think it would be interesting to see what she thinks.</p>
<p>But I’m not sure if its frowned upon to discuss the test with AP teachers since none of my AP teachers have mentioned the tests other than congratulating us on taking them.</p>
<p>@lolzicopter. The rate of photosynthesis for a plant with chlorophyll a would be low because green is the color the plant reflects. The plant reflects green and absorbs the other wavelengths so the answer would be opposite to what you said.</p>
<p>The lowest photosynthetic rate would be for the green light since barely any is absorbed and you need photons to excite the electrons, right?</p>
<p>So, there were parts a, b, and c for FRQ #1. Wow, so b was a complete fail. Not even off-topic just the answer was the exact opposite of what I said. So, assuming b was missed. How many points of of the 10 do you think the rest of that question will be worth?
Considering it wanted opposite answers and for the answers to be JUSTIFIED, I really hope b doesn’t amount to a whopping 6 of the 10 points! 
(3 parts & 3 justifications)</p>
<p>Wrong, high photosynthesis for red and violet because they are being absorbed, thus utilized. The green is reflected and so does not allow for photosynthesis.
@lolzicopter</p>
<p>An example of organisms that would perform both photosynthesis and cellular respiration would be peas correct? Cause that’s what I put …</p>
<p>It’s so many things guys. Plants do. Peas do. Cyanobacteria (I think) undergo such a practice.</p>
<p>So, no one answered but could someone who knows the answer tell me whether this is correct?</p>
<p>For part C in FRQ #1. (Question is below for reference.)</p>
<p>(c) Bacteriorhodopsin has been found in aquatic organisms whose ancestors existed before the ancestors of
plants evolved in the same environment. Propose a possible evolutionary history of plants that could have
resulted in a predominant photosynthetic system that uses only some of the colors of the visible light
spectrum.</p>
<p>ANSWER: Adaptation by surviving efficiently on a few colors of light is better than being less efficient in photosynthesis on a wide variety of colors of light. Survival of the fittest through evolutionary adaptation helped many of these plants evolve to their current state. Is that answer sufficient? Thanks</p>
<p><strong><em>Also, will ‘respiration’ in question 4 get credit or is ‘cellular’ needed before the word respiration?
Can anyone briefly explain
how each process promotes movement of carbon through the cycle. For each process, your explanation
should focus on the role of energy in the movement of carbon.
^^ I would like to know this answer as well! Thanks!!!</em></strong></p>
<p>For the carbon one this is what I put, or close to what I put:
Process I is photosynthesis or more specifically, the Calvin Cycle as it fixes CO2 into organic molecules such as glucose. Organisms like humans eat plants or organisms that ate those plants and use the organic molecules to make CO2 during cellular respiration, more specifically during the process of making pyruvate into acetyl-coA and during the Krebs cycle. When we exhale, we release the CO2 from cellular reparation, continuing the cycle.
Peas would be an example of an organism that carries out both processes.</p>