Question

The reflex arc which is made up of two neurons is known as:
A. Monosynaptic reflex arc
B. Disynaptic arc
C. Polysynaptic reflex arc
D. Asynaptic reflex arc

Answer 1

Hint: Reflex arc is the shortest possible path which an impulse takes to travel from the receptor to the brain. It follows a specific nerve pathway. Now, synapse is the point of contact of two neurons where the axon ending of one neuron transfers the information to the dendrites of another neuron.

Complete answer:
To solve the question, we must be well aware of the reflex action and the synapse.
 Now, reflex action is the immediate response to the stimuli. When the receptor gets the stimulus an impulse is sent to the brain through the sensory neuron to the central nervous system. From the sensory nervous system orders are sent through the motor nerves to the effector to give a response to the stimuli.
The structural and functional unit of the nervous system is the neurons. Now the neurons are so arranged that the axon ending of one neuron lies in the close vicinity of the dendrites of the next neuron. This junction is known as the synapse. Now, two neurons would make one synapse and would be called monosynaptic, three neurons would make two synapses and would be called disynaptic and so on.

Now we know that the correct answer to the question is monosynaptic reflex arc.

Note: It must be noted here that the number of synapse in almost every case would be one less than the total number of neurons involved. This is so because there can be only one junction present between two neurons.