do Ecosystems constantly go through cycles of regeneration and change?

During binary fission, what events must occur before the cell splits into two new cells?

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above

Explain the physiological changes that occur when the hypothalamus stimulates the sympathetic nervous system. you can make a flowchart or a simple step process. be sure to include all chemicals/hormones secreted, glands involved and the functions of each chemical/hormone.