<p>Does cephalization have anything to do with the ectoderm from gastrulation and the neural crest? that was all I could think of to talk about.</p>
<p>No. Cephalization is simply the form of the head which arises from bilateral symmetry. Again I am surprised that 2 out of my 3 books had NO talk about cephalization inside of the review... (and no MC questions about it).</p>
<p>none of my ap bio study books said anything about cephalization.. but my big fat book did but it had one little section in it out of like 800 pages..how do they expect us to remember something small like that</p>
<p>Ok, then I got that one completely wrong. There were 3 sentences in my book on it (according to someone who actually checked).</p>
<p>I think that the essays were like a polar opposite of what last year's essays were, or so I've heard. Somehow, we just got lucky and were nailed with the toughies. Hopefully they will be lenient. Maybe they will give brownie points for all of you that drew happy faces and stick figures in the circle. Haha, one can hope... a good joke is always worth a good point, right?</p>
<p>cepha.....sefa..ceefa...cephalization is so gay</p>
<p>cephalization is the concentration of sensory organs in the anterior segment of an animal....</p>
<p>number four was crazy ridic....totally threw me off....even though we went over it in class :/</p>
<p>My first reaction to the FRQ: *** is this? We didn't learn ANY of this in class! Well, except for #1...</p>
<p>wait a min.
okay 4b was: describe how gene can be inserted, how you can identify the recombinant bacteria, and how to make sure genes are expressed.
aren't the last two essentially the same thing and have the same answers? like you can test the gene for, let's say penicllin, by placing the bacteria in a dish of pencillin. so aren't the last two pretty much asking for the same thing??
but testing for them doesnt mean that the gene expression is ensured...
ahh im so confused!!</p>
<p>there's a certain process, transformation, that ensures the gene is expressed.</p>
<p>yeah i didnt know what to put for the expression one so i completely b/sed it (lol!) and then i put that you should test them with the gene they're supposed to be immune to or whatever, and that identifies them.
would that be wrong?</p>
<p>I said to use complementary DNA without the introns to ensure expression of the gene.</p>
<p>In order to ensure the expression of a particular gene you wish to see expressed, you need to first synthesize (or just obtain) a plasmid that contains that particular gene. Then, through a combination of heat and cold shock, you induce the bacterial cells to enter a state of competence, during which they have the ability to take up extracellular DNA. Then, you just need to grow the bacteria in a nutrient medium and observe. However, in order to ensure the expression of a particular gene, you need to put a marker gene on the plasmid along with the gene you want expressed. Marker genes are genes used to determine if a piece of DNA has been successfully inserted into a host organism. Personally, I used a gene that codes for resistance to ampicillin, an antibiotic. Then, by growing the bacteria in a nutrient medium with ampicillin present, only the bacteria with ampicillin resistance will grow, and if they express the gene for ampicillin resistance, then they must also express the original desired gene (since both genes lie on the same plasmid).</p>
<p>Yeah see i put that, but i put that for "identifying the recombinant bacteria" because if you do put ampicillin-resistant bacteria in a thing of ampicillin, then the bacteria with the resistance would obviously grow, thus proving your point that those are the bacteria with the plasmid.</p>
<p>ami completely wrong? lol...</p>
<p>4AAAA WHAT DID U DRAW? like whats the correct answer ahha</p>
<p>Cut the circle up with lines, lable the restriction enzyme that cut it there, and lable the lengths.</p>
<p>First cut into the circle with 2 marks that will make one part 3/10 of the circle and the other 7/10. Divide the 3/10 into 1/10 and 2/10 and the 7/10 into 4/10 and 3/10 with the second restriction enzyme. make sure the 3/10 is next to the 1/10 and the 4/10 next to the 2/10 section.</p>
<p>for 4b- to insert u do PCR then heat shock.</p>
<p>For 4A I drew a baseball with a giant bat hitting it. I still had plenty of room for B and C.</p>
<p>Did everyone go for really long answers, because mine were very concise; just said what I knew no conclusion or intro or anything, yet I still feel that I got at least 5 or 6 on 1 and 2, 9 or 10 on 3, and 3 or 4 on 4</p>
<p>for #1, I used phospholipids, K/Na transport pumps, and major histocompatibility complexes (for recognition by the immune system cells). </p>
<p>I did genetically engineered pesticide-resistant corn for 4c.</p>
<p>For #2, I described the concurrent evolution of senses with centralized nervous systems. Has anyone noticed that all the intelligent organisms have the most acute senses? (from a phylogenetic standpoint, the cephalopods, chordates, and arthropods have the most complex senses and brains). And echinoderms, while the closest phylum to chordates, are also notoriously lacking in senses. Organisms that sense more must develop a means to distinguish among the vast amounts of stimuli they encounter - and that means is brainpower. It’s much more complex (and adaptive) than reflexively reacting to chemical gradients (which is what the most simple invertebrates do). I said that it started with the ganglia of flatworms.</p>
<p>Ugh though, I didn't say anything about bilateral symmetry.</p>
<p>The lab questions are soooo boring for self-studiers.</p>