Univ. of Illinois, Urbana-Champaign Bio/Neuro 303 Chapter 13 - Study Questions *** LAST UPDATED 05 October 2002 *** 178. A feature that seems to be common to olfactory systems in nearly all animals is a. the presence in the brain of regions containing densely packed neurites and synapses, called glomeruli. b. an across fiber coding in which a single olfactory receptor cell can usually respond to several different types of chemical stimuli. c. some mechanism for protecting the fine filaments or dendrites of olfactory receptor cells from drying out. *d. all off the above. 179. Gustation is considered a separate sense from olfaction. This statement is a. true, because the receptors for each are located at different ends of the body. *b. true, because input from gustatory and olfactory receptors are processed in different regions of the brain. c. false, because both sensory systems deal with the same stimuli. d. false, because all gustatory and olfactory receptors use the same transducer mechanism. 180. Transduction in odor receptors is carried out by the following sequence of steps: a. Activation of receptor by odorant molecule--> activation of cAMP-dependent protein kinase C-->activation of adenylyl cyclase-->activation of G protein-->closure of K+ channel. *b. Activation of receptor by odorant molecule--> activation of G protein-->activation of adenylyl cyclase-->activation of cAMP-dependent protein kinase C-->closure of K+ channel. c. Activation of receptor by odorant molecule--> activation of adenylyl cyclase-->activation of G protein-->activation of cAMP-dependent protein kinase C-->closure of K+ channel. d. Activation of receptor by odorant molecule--> activation of G protein-->activation of cAMP-dependent protein kinase C-->activation of adenylyl cyclase-->closure of K+ channel. 181. In insects that communicate via pheromones, you would expect the animal to have an especially dense array of a. mechanoreceptors. b. photoreceptors. c. hygro- (humidity) receptors. *d. chemoreceptors. 182. Pheromone-detecting sense organs on an insect are most likely to be found on the animal's a. feet. b. tongue. *c. antennae. d. abdomen. 183. In an insect, an EAG (electroantennogram) can be used to study the animal's a. ability to discriminate different solid foods. *b. sensitivity to air-borne chemicals. c. sensitivity to sound. d. ability to detect a potential predator. 184. An electroantennogram (EAG) is a. a record of movements that an insect's antenna makes when it is exposed to a pheromone. b. an imprint of radioactive tracer binding with receptor sites on an antenna. *c. a record of the summed electrical activity of chemoreceptors in an antenna. d. none of the above. 185. Electroantennogram experiments with moth antennae can be used to investigate *a. the sensitivity of the insect's chemosensory system to different substances. b. the distribution of chemoreceptors on the antennae. c. topographical organization of the moth's chemosensory system. d. none of the above. 187. Gustatory receptors are a. chemoreceptors, and have a topographic organization in the brain. *b. chemoreceptors, and generally use an across fiber code. c. mechanoreceptors, and generally use a labeled line code. d. receptors for smell, and generally are spatially organized in the brain.