Water is a limited resource, despite it being very useful. We still use it very often because there is a bountiful amount of it, but it is not abundant, obviously we have enough to last you and I, but we will eventually run out. If anything, it'll become rarer and increase in price, but I have a feeling we will either find water somewhere else, or die out before then.
Prokaryotic cells- Lack a membrane bound nucleus
Eukaryotic cells- Have a membrane bound nucleus
TIP: remember PROkaryotic= for NO membrane bound nucleus
A) Biological, physical, and chemical.
b) Physical: sediment radioactive material and heat.
c) Chemical: organic/inorganic: heavy metals, nutrients & pesticides.
Global warming/climate change