Answer:
A threshold level depolarization.
Explanation:
In a neuron, the action potential threshold is known as the point of depolarization where the neuron fires, when the neuron reaches a point, it will fire and if it does not reach the point of depolarization, it will not fire and it helps to transmit the information to another neuron.
A neuron transmits the information with the help of electric impulses which are sent through its axon. When a neuron in an inactive phase, more +ve charged ions recline outside the axon membrane. In the process of stimulation, the axon membrane admits more Na+ ions and providing the neuron more +ve charge.
The control is the group of no fertilizers.
A control in an experiment is usually the group without the variable to be tested. In this case, the farmer wanted to test the effects of fertilizers, therofre the group without it is the control group.
This colored pigment is known as Hemoglobin. Hemoglobin is contained in the red blood cells of vertebrates and gives these cells their red color.
