我想問一題bio ge問題~~

how would you define "the most sensitive"
There are two respects to answer your question. For chemical testing reagent, it is defined that even the lowest concentration of the chemical substance is used, the chemical testing reagent can still give you a +ve result. For example, the use of anhydrous copper (II) sulphate to test water. Even a very little drop of water is used, blue color can still give off due to CuSO4 + 5 H2O → CuSO4‧5H2O
For receptors such as pain receptor and stretch receptor. They can stimulate an action potential(等如nerve impulse) even the intensity of stimulus is very weak. This means that their threshold value of the generation of action potential is very low. And you can say that those receptors are the most sensitive to the stimulus.
+ve = positive
I hope you will find my answers helpful.