<p>I have a feeling that the answer to 4c, the one about how it can help and hurt humans is that:</p>
<p>Although we can immunize for the disease and nearly eradicate it (tuberculosis), it also naturally selects for a drug-resistant bacteria. Have you heard of the guy they locked up for having a drug-resistant TB strain?</p>
<p>so i still don't know what question 2a was all about. caphilization, great, but no one has said what it is.</p>
<p>for 4c or whatever it was about the gene being expressed I just said do experiments to isolate the bacteria, such as AMP/penicillin on an agar plate to kill all bacteria that don't have a resistance to it if you inserted a gene for resistance to penicillin or something.</p>
<p>it was about helping humans, and destroying an ecosystem, so i wrote about genetically enhanced tomatos that bugs couldn't digest, obviously helping humans, but destroying bugs creating a chain effect throughout that ecosystem.</p>
<p>there was no one answer to 4C, it was very open ended</p>
<p>i put:</p>
<p>genetically enhanced algae that carries out photosynthesis more effiecently, will affect the underwater ecosystem by causing mass eutrophication which kills animals in the marine biomes. The algae help humans by producing mass oxygen and countering the greenhouse effect.</p>
<p>4c- harms- exponential growth, no predation no competition, could reach highest BIOTIC POTENTIAL, and it will destroy other species- it came on a question for FRQ last year.</p>
<p>for 2a , do u think i will get a point for formation of nervous system during neurulation, after gastrulation- even tho it is during gastrulation.
when r answer keys posted.</p>
<p>for 4C I talked about GMO corn, and how it grows larger and faster, which is better for human consumption. However, it produces pollen which travels by wind onto milkweed. The migrating Monarch butterflies then cannot lay their eggs on the pollen-covered milkweed.</p>
<p>so is it true that phospholipids and cholestrol are not 2 diff macromolecules.</p>
<p>Gylcocalyx</p>
<p>"The outer component of a cell surface, outside the plasmalemma; usually contains strongly acidic sugars, hence it carries a negative electric charge."</p>
<p>hmm glycocalyx not actually part of plasmalemma (cell membrane). but i guess the CB probably will accept it anyway. just quoting wiki.</p>
<p>Phospholipids and cholesterol are different macromolecules, but they fall under the same class of macromolecule (lipids).</p>
<p>If I remember correctly, the question never asked specifically for one example from each class of macromolecules, just different macromolecules, period. So using both phospholipids and cholesterol as examples should be fine...</p>
<p>for 2a - the word was cephalization. i believe it means that segmentation in an animal is blocked off to specialize for certain functions. i connected that to how it allowed more complex organisms to develop with more advanced circulatory & digestive systems but at that point i was just rambling to get points.</p>
<p>for the macromolecules, i put phospholipidis, carbohydrates, & proteins. carbohydrates were used for cell recognition but i wasn't sure on this one so i just put the only other macromolecule i could think of.</p>
<p>for GMO, i used agricultural crops and how we make them resistant to herbicides/insecticides by inserting genes but these can spread to other plants (like weeds) b/c plants can pick up genes easily or something and then wipe out indigenous plants, destroying ecosystems and such. i think we read something about this in envrionmental science..</p>
<p>overall, i had trouble answering questions confidently so i rambled to get as many points as i can..</p>
<p>oh thank goodness :) i was gonna use the polysaccharides on the glycocalyx but i thought it wasn't part of the cell membrane so i used cholesterol instead</p>
<p>my teacher said that cephalization meant the evolution of a head or something like radial -> bilateral symmetry, organized brain, etc</p>
<p>i, however, did not know that and just rambled about gastrulation for the development part and something about annelids/ganglia</p>
<p>is it okay is i said glycerol, protiens, and fatty acid side chains as my 3 macromolecules?</p>
<p>the free response q's are online</p>
<p>mod amistad-</p>
<p>sorry for posting before the 48 hours, but i thought i was following the instructions that you yourself posted:</p>
<p>"and NO discussing of FR questions until at least 48 hours after the exam."</p>
<p>also</p>
<p>"UNALLOWABLE CONTENT
1. The articulation of multiple-choice exam questions and answers.
2. The articulation of free-response questions within 2 days of the exam in which they appear."</p>
<p>i wasn't discussing any questions. i was going through a food chain that was possibly an answer to a certain question that was never mentioned. No question was ever "articulated," straight from the CB message.</p>
<p>please correct me if I have misunderstood the rules.</p>
<p>Cephalization is the development of a brain or a region of higher processing in the anterior end of an organism that features bilateral symmetry. One of the earliest organisms/invertebrates to exhibit this feature was the Planarians, belonging in the flatworm Phyla (I Forgot the name). They have two sets of ganglion (nerve tubes) that stretch through the length of the body (one on each side), but both converge in the head near each eye. This was the first primitive development of cephalization in animals. I think also that in the chordates, lancelets were the first organisms to exhibit a trend towards cephalization, but I might be wrong on this point. Cephalization allows an active animal to focus nerve potential in one region of its body so that it can more easily catch prey, move around, respond to environmental stimuli, and react quickly to predators. Cephalization is one of those processes that develops as a side consequence of bilateral symmetry, and replaced the random, diffusive nerve nets found in earlier Cnidarians and sessile sponges (Phylum Porifera). In higher mammals, it allowed the development of the brain and the separation of this organ into the forebrain, midbrain, and brain stem (or Medulla), which results in cell differentiation and separation of different areas that controll and process various stimuli. </p>
<p>That's what I put on the AP Test. I was quite familiar with this part.</p>
<p>ok it seems like a lot of people know more about this than i do and i thought i did fairly well.. so im hoping none of u r from the south and that its still possible that i get a 5 :) lol</p>
<p>also if anyone knows anythign about computers in ehre.. i cant view .pdf files so if anyone knows what site to go to to get a downloadable program thatll let me read them thatll be great...</p>
<p>Seriously cephalization was NO WHERE in my study books. But I took zoology. This is where I learned about it and the platyhleminthes (the first phyla with cephalization.)</p>