A muscle fiber will respond to a stimulus when that stimulus reaches the threshold level. These local classified potentials which are mainly related with external stimuli extent the axon preliminary segment and construct up to they manage to extent the threshold value. The bigger the stimulus the larger the depolarization or try to reach threshold.
Answer:
Biologists measure the number of trophic levels in an ecosystem so as to check its stability and health.
Explanation:
Trophic levels are the feeding position in a food chain such as primary producers, consumers, etc. They are positions that an organisms occupies in a food chain (series of steps in which organisms transfer energy by eating or being eaten);- what it eats and what eats it.
Theoretically there is no any limit to the number of trophic levels in a food chain or number of organisms that live on each level.
Answer:
the citric acid cycle and preparatory steps