Marcus is excited to be working in the laboratory of Dr. Flores, an expert on electrical signaling in neurons. However, he is surprised to learn that the research is done on squid axons placed in sea water. He asks Dr. Flores the reasons for this approach. All of the following reasons are among those that Dr. Flores provides EXCEPT
A) that a recording electrode can be inserted into a squid axon without disrupting its function.
B) that the readings from inside the axon can be compared to the readings from the surrounding seawater.
C) that squid axons are myelinated, increasing the speed of propagation of an action potential.
D) that squid axons can be as great as 1 millimeter in diameter and are visible to the naked eye.

Question

Marcus is excited to be working in the laboratory of Dr. Flores, an expert on electrical signaling in neurons. However, he is surprised to learn that the research is done on squid axons placed in sea water. He asks Dr. Flores the reasons for this approach. All of the following reasons are among those that Dr. Flores provides EXCEPT
A) that a recording electrode can be inserted into a squid axon without disrupting its function.
B) that the readings from inside the axon can be compared to the readings from the surrounding seawater.
C) that squid axons are myelinated, increasing the speed of propagation of an action potential.
D) that squid axons can be as great as 1 millimeter in diameter and are visible to the naked eye.

Quizplus · Accepted Answer

Squid axons are not myelinated; they are large in diameter, which helps in the rapid conduction of action potentials, but they do not have myelin sheaths like some vertebrate axons do. Myelination is a characteristic of certain vertebrate neurons that increases the speed of action potentials by insulating the axon and facilitating saltatory conduction. The large diameter of squid axons, rather than myelination, is what allows for their efficient signal transmission.

Marcus Is Excited to Be Working in the Laboratory of Dr