a proton located in the atom is the nucleus
Answer:
DNA replication needs to occur because existing cells divide to produce new cells. Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!
Lungs appear collapsed in the fetus because they are filled with amniotic fluid and they have never been inflated with air yet.
Sea Floor Magnetism, Fossil Evidence, <span>Distribution of volcanoes and earthquakes on the globe </span>and Continental drift.