A 45-year-old man adds lots of high-fiber wheat and bran foods to his diet to reduce his cholesterol. He loses 30 lb on the new diet, but has undesirable side effects such as stomach cramps, flatulence, and diarrhea. His gastroenterologist diagnoses a syndrome called gluten-enteropathy or celiac sprue. Which of the following is decreased in this man?

#Question id: 11225

#Unit 7. System Physiology – Animal

What happens if twice as many inhibitory postsynaptic potentials (IPSPs) as excitatory postsynaptic potentials (EPSPs) arrive in close proximity at a postsynaptic neuron?

#Question id: 11226

#Unit 7. System Physiology – Animal

At the neuromuscular junction, the neurotransmitter acetylcholine (ACh) is degraded by acetylcholinesterase. If a neurophysiologist applies the naturally occurring acetylcholinesterase inhibitor, onchidal (produced by the mollusc Onchidella binneyi), to a synapse, what would you expect to happen?

#Question id: 11227

#Unit 9. Diversity of Life Forms

Mycoplasmas are bacteria that lack cell walls. Based on this structural feature, which statement concerning mycoplasmas should be true.

#Question id: 11228

#Unit 9. Diversity of Life Forms

Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which of these observations comes closest to explaining the basis for placing these organisms in different taxa, well before relevant data from molecular systematics became available?

#Question id: 11229

#Unit 9. Diversity of Life Forms

Which is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.

#Question id: 11230

#Unit 9. Diversity of Life Forms

Which statement about bacterial cell walls is false?