Name_______________ Lab day (circle one): M T W ThBiology of Marine Organisms Midterm Exam 3, Fall 2012 1) ____active_______ transport is characterized by organisms moving under their own power, while _______passive_____ transport is characterized by organisms moving mainly via water currents. (4 pts) 2) Which of the following is required for movement using a hydrostatic skeleton? (1 pts)a. Compressible fluidb. Inflexile outer body wallc. Variable volume of fluidd. All of the above are necessarye. None of the above are necessary 3) The nautilis controls its buoyancy through control of ____osmotic pressure---siphuncle tissue_____. (2 pts) 4) The basic unit of contraction is the __sarcomere_____. (2 pts) 5) True/False Muscle contraction requires the presence of sodium ions. (1 pts) TRUE False, calciumIt’s true, both are required but we only talked about calciumBLAINE GRIFFEN: I don't think we covered the role of sodium ions in muscle contraction - we won't worry about this. BLAINE GRIFFEN: I would say this is false. It requires Ca+. However, sodium is indirectly important for muscle stimulation by the nervous system. 6) What role does this ion (the one in number 5 above or another one) play in muscle contraction? (4 pts)It requires Ca+. However, sodium is indirectly important for muscle stimulation by the nervous system. Without the calcium, the thin actin and thick myosin would not be able to join (which basically creates the muscle contraction). The calcium is needed to bond to the troponin. No calcium = nocontraction, simple as that. Sodium does not affect the muscle contraction, it correlates with the nerves bound through the muscles. 7) True/False Mammals that run, swim, and fly move with similar efficiencies. (1 pt) 8 ) True/False The higher energetic efficiency of semi-aquatic animals explains the evolutionaryshift from terrestrial to marine mammal life. (1 pt)Can someone just explain real quick why they got True?I thought this was false because semi-aquatic animals have a lower energetic efficiency since they swim near the surface, which creates more drag.I thought it was false because animals migrated from the ocean to land, so the last part of the statement wouldBLAINE GRIFFEN: Emily: Semi-aquatic animals are exerting the energy to move forward (same as terrestrial and fully aquatic mammals), but they are at the same time exerting the energy required to push water up against gravity since they commonly swim at the water's surface. This extra bit of energy expenditure makes swimming relatively inefficient for these animalsDoes that help any?? I think it really is false.I think it’s false because semi aquatic animals have a low energetic efficiency^^^ This. They have extremely low energetic efficiencies (high energy expendature) compared toother organisms. 9) For each of the organisms below, indicate whether they have a hydrostatic skeleton, exoskeleton, or endoskeleton (10 pts). a. Polychaete worm__hydrostatic skeleton_____ b. Red rock fish___endoskeleton______ c. Oyster______exoskelton_____ d. Cephalopods___hydrostatic, exoskeleton, and endoskeleton____ can someone explain why this is all three? I thought it was just an endoskeleton. octopus: hydrostatic, nautilus: exo i think. i cant get on the chat, someone ask!! Cephalopods in general are all 3, octopus is only 1! thankssssssHE SAID ON THE CHAT THAT NAUTILIS IS EXO….SQUID IS ENDO… AND MOST OTHER ARE HYDROSTATIC e. Hermit crab_ hydrostatic and exoskeleton ___Why is this hydrostatic too?? I got it thanks!Im not sure, he said that in lecture…its because the back of their body is hydrostatic (the part that goes in the shell) and their claws and the shell are exoskeletons Hey, are the hermit crab and cephalopods the only 2 that have multiple?I think so f. Hawksbill turtle turtle___endoskeleton_____g. Anemone_hydrostatic skeleton_____ h. Great white shark____endoskeleton and hydrostatic skeleton BLAINE GRIFFEN: Alexander: The great white has an endoskeleton, but it's skin and muscular system work together to form a type of hydrostatic skeleton becuase the muscles attach directly to the inside of the epidermis.Im confused why in the lecture notes say the muscles attached to the skin create an exoskeleton? Even though hydrostatic skeleton makes much more sense i. Sea star___endoskeleton____ j. Diatom_______exoskeleton_______ 10) Rank the following in terms of energetic costs to the organisms, with one being the highest cost and 3 the lowest. (3 pts) ___3__Hydrostatics _1____Chitinous __2___CaCO3Is anyone still on here? why is hydrostatic the lowest?????Because it doesn’t require nearly as much energy to produce multiple shells (like chitinous organsims) or have to constantly grow a shell like (like clams). Also CaCO3 will change thickness wit predation hydrostatic organisms do not worry about this because they can not imagine making their skin thicker for protection. Imagine a human whos skin only grows with them while the other two grow almost continously through the animals lives. Hope that helped I’m not sure why hydro is the lowest but I can tell you why chitin is the highest if you want?Generally, the chitninous shell will have the greatest cost because, as you state, it must be replaced every time the organism grows bigger, whereas the CaCO3 shell just has to keep up with growth through incremental increases. However, in todays acidic ocean, the cost of CaCO3 shells are increasing11) How do excessive carbon emissions alter your answer to #10? Explain in 2 sentences or less (your explanation should include the carbonate compensation depth). (5 pts) CCD is the depth in oceans below which the rate of supply of CaCO3 lags behind the rate of dissolution, such that no CaCO3 is preserved. As oceans become more acidic due to excessive carbon emissions the CCD is shallowing. When arag<1, like in the CCD, CaCO3 dissolves and skeletons cannot be formed because it takes too much energy for the organism to keep up with maintaining the dissolved shell, thus CaCO3 would have the highest energetic cost.12) Define each of the following structures AND give an example of an organism where each structure is found (10 pts).a. Statocyst – used in most invertebrates for balance, statolith inside falls with gravity, sensory hair will detect statolith, The Jelly Fish is an example b. Ocelli – Simple eyes, sense light but not direction, shadow response, The scallop is an example c.