May-2012- Biology (E/M)

<p>well it asked which was required and clearly haploid gametes aren’t required in all types of sexual reproduction. and plus polyploidy is part of the biology curriculum so who knows if that’s what they meant. if it said zygote that goes through mitosis, i still think that’s right</p>

<p>But zygotes form by meiosis not mitosis…which is clearly a wrong answer…</p>

<p>WAIT.</p>

<p>Did the questions say ZYGOTE forms by mitosis or undergoes mitosis?!?</p>

<p>Cuz if it says undergoes mitosis I actually think you might be right.
Zygotes form by meiosis but continue growing thru mitosis…</p>

<p>haha I wish I remember, the only thing I recall is eliminating the rest of the answers and seeing mitosis in that chioce. can’t believe i need to wait another couple weeks for scores</p>

<p>That’s what I put as well, I thought that it meant the guard cells would shrink making the opening to the somata larger and allowing water in… Ya it was a bit of a stretch, but could someone give me a definite answer? </p>

<p>Sent from my Desire HD using CC</p>

<p>for that im pretty sure the answer was the one about osmosis</p>

<p>well for guard cells-it is definitely osmosis of water in cells. When k flows in, the cells become TURGID and the stoma open-im guarenteed, pls trust me.
Now for this whole polyploidy vs mitosis nonsense-i think my original question got skewed.
This is the question: which of the follwoing is required for sexual reproduction: and it seems we are down to haploid gametes and mitosis. Mitosis is def not the right ans, BUT it is very possible that haploid gametes are not the answer either-polyploidy is a very valid point b/c there are gametes (esp in plants) that end up becoming autopolyploids (3n) and still very viable. The original issue was: are centrioles required? I thought not, and so the only possibility to me seemed like haploid gametes b/c polyploidy is an anomaly. But dont get me wrong, this is not necessarily the correct ans, it could be another that we are all looking over…</p>

<p>so can you confirm for me that the choice that mentioned zygotes was saying that it was made through mitosis or that it goes through mitosis?</p>

<p>The answer was definitely haploid gametes. That is one of the defining characteristics of normal sexual reproduction. Polyploidy is the exception to the rule. It is a kind of mutation. None of the other answers were plausible.</p>

<p>Why does a high volume of CO2 contribute to global warming?</p>

<p>Wait it’s definitely cuz it’s a greenhouse gas but I totally forget if I put that…</p>

<p>it’s a greenhouse gas and keeps the heat in the atmosphere</p>

<p>Guys:</p>

<p><a href=“Role of 2n Gametes and Endosperm Balance Number in the Origin and Evolution of Polyploids in the Tuber-Bearing Solanums | Genetics | Oxford Academic”>http://www.genetics.org/content/163/1/287.full.pdf&lt;/a&gt;&lt;/p&gt;

<p>“The incidence of 2n gametes is frequent in the plant kingdom”</p>

<p>exactly it’s not such a small anomoly that you could just ignore it (and plus you should know about polyploidy for the test) and the question was asking which of the following are required. all forms of sexual reproduction have zygotes so it all depends what that choice was saying about mitosis. finally someone that agrees with me</p>

<p>In the PLANT kingdom. The question referred to plants and animals. It’s fairly rare in animals.</p>

<p>hey guys do u know when we r allowed to officially (without breaking rules) discuss the bio exam? is it after we get scores? or can we never discuss?</p>

<p>im a pretty honest person so i wont say anything haha</p>

<p>exactly the question was referring to PLANTS and animals and haploids aren’t required for sexual reproduction in plants so that would make that choice wrong</p>

<p>I thought it was at least two pairs of chromosomes because thats was all that was left after you eliminated everything else.</p>

<p>Oh that said at least two pairs of chromosomes? i don’t remember seeing the at least but i probably missed that</p>

<p>if it did say at least i believe that would be the correct answer (plus they accounted for polyploidy by putting at least)</p>

<p>nihilism, thats what i put too.</p>

<p>do you think this might have a better curve than usual? i found it kinda hard and missing only 2 to get 800 seems kinda ridiculous</p>

<p>My reasoning was that you need to have a sex chromosome+another one. But its shady because [Jack</a> jumper ant - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Jack_jumper_ant]Jack”>Jack jumper ant - Wikipedia) has only 1 pair of chromosomes.</p>

<p>Augh well ■■ it. I’m cancelling.
I missed like 10. I’ve never done so bad. A+ in my AP Bio class. I ace everything bio related. How did I fail this so miserably…This test was brutal. Is May just known for its notoriously difficult tests???</p>

<p>Cuz all my friends got 800s and say how EASY SAT Bio is, but frankly, I though todays test was by far the hardest Bio test I’ve ever taken.</p>