In order to "invest" in later stages to get more energy per glucose molecule. It could also be because that is how it is done, it wouldn't be as efficient unless these stages were performed.
hope this helps!
Cuando el hielo se calienta, comienza a derretirse y a formar agua, esto es progresivo
First, weather is the atmospheric condition occurring over a short period of time in a relatively small location. Climate, on the other hand, is the overall environmental condition over extended periods of time. Next, the water cycle is when water from the surface evaporates as water vapor under high temperatures and condenses in the atmosphere under lower temperatures and precipitates back to the surface. In the event that water evaporates more than it condenses then the weather will be warm to hot, the ground will be relatively dry, and drought over extender periods of time may ensue. On the other hand, if water condenses and precipitates more than it evaporates, then there will be a rainy season, and may extremely lead to landslides and floods.