Answer:Prophase
Explanation: Prophase is when chromosomes are made and the nuclear membrane breaks it down and later into the appearance of spindle fibers.
The biosphere is everything that makes up life like plants and animals for instance but ecosystem is all the living and nonliving factors that affect the area hope this helps
Chemical energy, hope this helps. Correct me if im wrong but im sure its chemical energy
The answer is because it lowers the number of chromosomes in half, ensuring that the fusion will have the appropriate amount of chromosomes after the fusing of the sperm and the egg.