Answer:
<em>The correct option is d) once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.</em>
Explanation:
In the field of biology, the all-or-nothing law can be described as a principle which focuses on the strength with which a nerve or muscle fibre responds to a particular stimulus, this strength being independent of the strength of the stimulus. The functioning of the impulse is just like the trigger of a gun. The more the force of a stimulus, the more will be the intensity of the nerve impulse.
A specific animal is A. species
We have heard about Respiration. In human beings, respiration is a cellular activity which takes place in the presence of oxygen and in result produces carbon dioxide. Jamal model is a clear manifestation of that process. Medulla is the region of a brain that controls the respiration activity. When we breathe we take in oxygen and the excess amount of carbon dioxide is removed from out body.
Brains cells have capability to detect the carbon concentration in blood and add excess amount of carbon from body to the air.
According to Twain man could not have ascended from lower animals (Darwin theory of evolution) because man makes cruel and horrible decisions, rather man descends from Higher animals. He proved his conclusions about man by using specific scientific method, he subjected every postulate itself to the crucial test of actual experiment and have adopted it or rejected it according to the results.