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Answer the following about the neuroethology of escape, for 10 points each.
[10e] These animals have enormous synapses in their stellate ganglia. Hodgkin and Huxley discovered action potentials in the giant axons of these animals, which innervate the mantle during jet propulsion.
ANSWER: squid [or Decapodiformes; accept cuttlefish; accept specific squid species; prompt on cephalopods, Cephalopoda, mollusks, or Mollusca; reject “octopus”]
[10m] Description acceptable. The teleost (“TEE-lee-ost”) C-start reflex uses the two Mauthner cells, which have these relative positions to each other. The withdrawal reflex in humans is paired with an extensor response in this position.
ANSWER: on opposite sides of the body [or opposite sides of the midline; accept contralateral; accept crossed extensor reflex; accept descriptions of being across the sagittal plane or across the longitudinal plane; prompt on lateral or on the sides]
[10h] The lateral giant interneuron mediating this response in crayfish is a true command neuron and has the first observed electrical synapse. Holding a lobster by the shell represses this escape response, in which the tail is flexed to propel a crustacean backwards.
ANSWER: caridoid (“CARRY-doid”) escape reaction [prompt on lobstering or tail-flipping; reject “cardioid”]
<Biology>

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Summary

2024 ACF Nationals2024-04-21Y1911.58100%16%0%

Data

BrownIllinois100010
North Carolina BChicago D100010
McGillClaremont Colleges1010020
Berkeley AColumbia B100010
WaterlooCornell A100010
Cornell BSouth Carolina100010
TexasGeorgia Tech1010020
VirginiaIndiana100010
Berkeley BIowa State100010
Chicago BJohns Hopkins100010
North Carolina AKentucky100010
MarylandVanderbilt100010
Columbia AMinnesota A100010
NorthwesternPenn100010
Toronto AFlorida1010020
Toronto BMichigan100010
Yale BTruman State100010
WUSTL ARutgers100010
Yale AArizona State100010