Ligandgated ion channels respond to chemical signals are usu

Ligand-gated ion channels.... respond to chemical signals are usually less selective than voltage gated ion channels, and will allow more than one type of ion to pass are all single polypeptides with multiple membrane spanning domains may respond to intracellular or extracellular signals One of the above is TRUE Two of the above are TRUE Three of the above are TRUE All of the above are TRUE None of the above are TRUE In an experiment, you microinject the strong calcium chelator \"BAPTA\" into a squid presynaptic neuron. BAPTA rapidly binds intracellular Ca^2+. Compared to non-injected controls you would likely observe... blockade of action potential conduction in the presynaptic neuron reduced postsynaptic membrane potential changes following stimulation of the presynaptic neuron increased neurotransmitter release from the presynaptic neuron two of the above none of the above Which of following statements about voltage gated sodium channels in the squid giant axon is TRUE? When open they pass only a few ions per second. They have a magnesium block at resting membrane potentials. They are opened by the neurotransmitter glutamate. Once the sodium channels open in response to a voltage step command, they tend to flicker closed and remain closed. All of the above are true. Gap junctions may exhibit all of the following features except... Are formed from Connexons Can pass electrical current bidirectionally Are relatively rare in the mammalian brain Amplify small incoming electrical signals into large regenerative potentials Synchronize the activity of populations of nerve cells.

Solution

7. (d) All of the above are true.

8. (d) two of the above

9. (a) and (c) are the true statement only.

10. Answer are (d) and (e).