Because our bodies work to fight off unknown substances like bacteria
The Savanna or Savannah
The Savanna is a biome that is typically found in Africa and is characterized by a tree density low enough to allow sunlight to reach the ground and allow for smaller plants such as grasses to grow. The growth of these grasses provides an optimal food source for herbivores, which is why large grazing herbivores such as zebras are found here. The presence of these herbivores allows for the existence of larger carnivores such as lions.
In order for cells to become whole organisms, they must divide and differentiate. Cells divide all the time. That means that just one cell, a fertilized egg, is able to become the trillions of cells that make up your body, just by dividing. Those trillions of cells are not all the same though.
Just a little while after you started out as a fertilized egg, your cells started performing specific tasks, even started to look different because of that. Differentiation means that one cell performs a different function than another cell, depending on where it is in your body.
Not sure if this will help.
The dirt sucks up the water from the surface to go to animals and plant and then becomes groundwater.
