During the plateau phase of the action potentials of myocardial contractile cells, which ion(s) is/are crossing the membrane

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

What is the most important inorganic material for livings things? ! due tomorrow!

Which atmospheric later is where earths northern and southern lights occur