They start at the dendrite is the correct answer...
They cannot travel backwards
And they are found in both the autonomic AND the somatic nervous system
The answer is
Limit the overuse and misuse of antibiotics in medicine and agriculture.
So, that the bacteria doesn't develop immunity against antibiotics.
Normally tree rings will disappear, damage, or go missing when the tree doesn't have enough nutrients, another factor that contributes to that is drought.