In lakes and ponds there is a whole ecosystem, with its animals and plants. Between them they are in charge of maintaining the entire habitat in favorable conditions for living. The fish tank does not have that cleaning system.
some one celled organisms reproduces by binary fission which is a process of cell division. The answer is 4.
Oxygen is the answer for this question.
The factors or characteristics of a Mediterranean climate are hot, dry summers and cool, wet winters and "located between about 30° and 45° latitude north and south of the Equator and on the western sides of the continents." -Britannica.com/science/Mediterranean-climate
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