Spontaneous depolarization of the nodal tissue in the sa node occurs at action potentials per minute:

It is 70-80 action potentials per minute.  The rate of phase 4 depolarization in the SA node sets the Heart rate, The SA node serves as the Pacemaker It has the greatest  automaticity And ability to  spontaneously generate an action potential.  

image result for describe the various types of gene mutationsghr.nlm.nih.gov

the types of mutations include: missense mutation: this type of mutation is a change in one dna base pair that results in the substitution of one amino acid for another in the protein made by a gene. nonsense mutation: a nonsense mutation is also a change in one dna base pair.

explanation:

a few examples of ethical concerns involving genetically engineering of humans include

-privacy of genetically tested people

- potential side effects

-long term effects