How does biosphere, hydrosphere, geosphere and atmosphere interconnect?

What is the next step in muscle contraction after the actin changes shape? (apex)

What is the name of the type of cell division that occurs in the prokaryotic cell cycle

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