Cell division, also called mitosis , occurs in multicellular organisms to create tissues, organs and organ systems.
50. because its 140 in 1991 and about 90 in 1992.
Cells spend most of their lives, about 78 percent of the time, not dividing in a phase called interphase. During interphase the cells get larger, replicate their chromosomes for cell division, synthesize substances that are essential to cell division, and build materials for growth and development.
Answer:
1- Two tectonic plates separate as they are pulled apart by convection in the mantle.
2- Molten material from the mantle rises up towards the surface due to convection and fills in the rift.
3- New oceanic crust is formed.
4- The crust slowly moves away from the ridge equally on either side.
5- Overtime, the creation of oceanic crust will cause continents to move.
Explanation:
Oceanic plates get separated and the spaces left among them are filled with magma coming from the mantle. When the magma reaches the surface, it suffers physical and chemical changes at the moment it gets in touch with the cold ocean water. The magma temperature descends and turns into a new oceanic crust. Plates keep separating from each other, and the new oceanic crust moves forward each side of the crest making a place for the ascension of new fluid hot material from the mantle. This constant process is what makes the continents eventually get separated each time more.
