<p>I also feel like a hydrostatic skeleton is only necessary for contraction; not necessarily for extension. Indeed, I only find the fluid being necessary in the context of “contracting muscles which exert a force on the fluid that then translates into movement” (summarized from multiple sources)</p>
<p>@cocytus: only deuterostomes have medodermal pouches per se. Plesae check the corresponding ch. in campbell to confirm that i’m reading this correctly…</p>
<p>@darksigma I think the operative word in the echinoderms vs annelids question was “near the blastopore”. The mesoderm forms in protostomes on the opposite end of the blastopore, not near it. A very tricky question indeed.</p>
<p>@asteracea: not true - [Redirect</a> Notice](<a href=“http://www.google.com/imgres?imgurl=http://www.mun.ca/biology/scarr/141993_Protostome_vs_Deuterostome.jpg..jpg&imgrefurl=http://www.mun.ca/biology/scarr/Protostomes_vs_Deuterostomes.html&h=600&w=528&sz=179&tbnid=X_tZrVNTPbVpsM:&tbnh=90&tbnw=79&zoom=1&docid=uGze8aeBRpmGhM&sa=X&ei=IdSBT9D5L8GViAKxofGrAw&ved=0CD8Q9QEwAw&dur=372]Redirect”>http://www.google.com/imgres?imgurl=http://www.mun.ca/biology/scarr/141993_Protostome_vs_Deuterostome.jpg..jpg&imgrefurl=http://www.mun.ca/biology/scarr/Protostomes_vs_Deuterostomes.html&h=600&w=528&sz=179&tbnid=X_tZrVNTPbVpsM:&tbnh=90&tbnw=79&zoom=1&docid=uGze8aeBRpmGhM&sa=X&ei=IdSBT9D5L8GViAKxofGrAw&ved=0CD8Q9QEwAw&dur=372)</p>
<p>About the annelids and mollusk question:</p>
<p>I thought it was much simpler. I put “a ciliated larvae in their life cycles” and annelids and mollusks have trochophore (which wikipedia says " a type of free-swimming planktonic marine larva with several bands of cilia" and that “Trochophores exist as a larval form within the trochozoan clade, which include the entoprocts, molluscs, annelids, echiurans, sipunculans and nemerteans.”) </p>
<p>May be the wiki could be wrong but I chose that answer anyway</p>
<p>@on the moon: i totally agree with that; indeed, that’s actually what I put. However, what makes the “mesoderm from solid pouches untrue?”</p>
<p>Oh…I just saw your post darksigma. I guess the answers were a and e. god I hate those questions that have multiple answers especially when they specify.</p>
<p>I don’t think that was a multiple answer question, though… they normally tell you in the question itself “choose all that apply.” that definitely wasn’t the case here… i think this is just a poorly thought out question or a poorly written one.</p>
<p>Also about the insect vs. mammalian respiratory question: </p>
<p>the choices were:
A) the mammal’s respiratory system is limited to a certain region of the body while the tracheal system of the arthropod is throughout its body
b) both systems are adaptions for living in air
c) Both systems have a closed circulatory system adjacent to a gas exchange surface
d) Both systems possess highly branched tubes
e) Both systems possess invaginated surfaces</p>
<p>I think the answer is e.</p>
<p>@darksigma: If it’s a mesodermal pouch, how is it a “solid ingrowth of cells”? But yeah, now I’m getting worried about how many other questions there were that required multiple answers that I didn’t notice, and how they will be graded.</p>
<p>@onthemoon: If it was asking for which one is untrue, the answer is c. Insects have open circulatory systems.</p>
<p>Here is another question</p>
<p>The freshwater fish black ghost is found off the coast of Ecuador. Suppose there are no close relatives and you have the ability to prevent black ghosts from immigrating or emigrating from their present population and there would be no further mutations. Which of the following statements is the best description of the future of this black ghost population?</p>
<p>A. The population will deteriorate after a few generations due to excessive inbreeding.
B. All evolution will stop immediately
C. The population will continue to evolve for a long time as selection acts on the variability produced by recombination
D. The population will stop evolving, but will continue for many generation as long as the environment remains constant
E. Major evolutionary changes will continue due to genetic drift</p>
<p>Questions 42-44</p>
<p>You have two true-breeding strains of pea plants with white flowers. Crossing these two strains yields an F1 generation that only has purple flowers. Self-crossing these purple flowers yields the following ratio of progeny with purple and white flowers: 9 purple and 7 white.</p>
<ol>
<li>How many genes in this cross are involved in determining flower color.</li>
<li>What fraction of the purple-flowered F2 progeny do you expect to produce only purple progeny when self crossed?</li>
<li>What fraction of the purple-flowered F2 progeny, when, selfed do you expect to produce the same 9:7 ratio of purple to white progeny.</li>
</ol>
<p>@asteraceae: you are right; I was confused for a moment </p>
<p>@emblem101: I put C as an answer. Choice B,D don’t make sense to me that when a population is segregated, the evolution just stops (like it’s a controllable force…) Choice A seems like a sweeping generalization. It was between C and E for me. I am having second thoughts about it though</p>
<p>Yeh for the black ghost question I’m between C and D because it says that there will be no mutations any more whichc is kind of odd because you can’t really control that. I remember when I was taking the test I was between those two choices but I don’t remember which I put.</p>
<p>Questions 90-95
A. Ca2+
B. K+
C. Both
D. Neither</p>
<ol>
<li>Smooth muscle contraction</li>
<li>Slow block to polyspermy</li>
<li>Long-term potentiation by NMDA receptors</li>
<li>Induction of the macula densa to activate RAAS</li>
<li>Saliva secretion by salivary glands</li>
<li>Mechnotransduction in hair cells</li>
</ol>
<p>Question 112</p>
<p>An invasive species of grasshopper from South America is destroying crops in Ohio. Which of the following would be the safest and most effective strategy to control the invasive insect population.</p>
<p>The top two choices were “Import a species of bird from South America whose natural diet includes these invasive grasshoppers” and “Release large numbers of a native species of grasshoppers into the area so that they will outcompete the invasive species”.</p>
<p>for the fish, I put a, although im not sure what the answer is.</p>
<p>42-44 was simple epistasis with 2 genes.</p>
<p>thoughts on question 112? I believe I put the importing predator option. But i think the introduction of native species might be right.</p>
<p>What answers did you put for 42-44?</p>
<h1>42 #43 #44</h1>
<p>A. 0 A. 1/9 A. 0
B. 1 B. 1/4 B. 1/3
C. 2 C. 1/3 C. 4/9
D. 3 D. 4/9 D. 1/2
E. 4 E. 1 E. 5/9</p>
<p>@darksigma: Yeah, sorry about that…you’re right about the mesodermal pouches a property of deuterostomes. Answer to that one should have been A then. Dammit.</p>
<p>The 9:7 ratio i had seen before; the answer is 2 genes, and 1/9 and 4/9 (I forget which order.) iBelieveSo, it was not simple epistasis with two genes, it was duplicate recessive epistasis, in which one trait is produced by both genes being dominant and the other trait is produced by having either one or two of the genes recessive.</p>
<p>how many of u guys were finalists in previous yrs?</p>
![http://www.google.com/imgres?imgurl=http://www.mun.ca/biology/scarr/141993_Protostome_vs_Deuterostome.jpg..jpg&imgrefurl=http://www.mun.ca/biology/scarr/Protostomes_vs_Deuterostomes.html&h=600&w=528&sz=179&tbnid=X_tZrVNTPbVpsM:&tbnh=90&tbnw=79&zoom=1&docid=uGze8aeBRpmGhM&sa=X&ei=IdSBT9D5L8GViAKxofGrAw&ved=0CD8Q9QEwAw&dur=372]Redirect](http://www.google.com/imgres?imgurl=http://www.mun.ca/biology/scarr/141993_Protostome_vs_Deuterostome.jpg..jpg&imgrefurl=http://www.mun.ca/biology/scarr/Protostomes_vs_Deuterostomes.html&h=600&w=528&sz=179&tbnid=X_tZrVNTPbVpsM:&tbnh=90&tbnw=79&zoom=1&docid=uGze8aeBRpmGhM&sa=X&ei=IdSBT9D5L8GViAKxofGrAw&ved=0CD8Q9QEwAw&dur=372%5DRedirect){kind=link}
