How does a threshold prevent a neuron from generating too many action potentials?

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna

If a keystone species is removed from an ecosystem

Which of these chinese regions is the most densely populated?