Fresh water is any body of water with a low salt concentration. Organisms in fresh water various challenges which includes; Osmotic concentration such that fresh water is permanently dilute and most cells cannot function at this concentration of ions. Varying temperatures, variation in oxygen levels and reproduction and life cycle due to permanence of habitat and physiological difficulty of regulating osmotic concentration in larvae and juveniles.
Natural selection is the idea that organisms that posses favorable traits that enable them to survive in their environment are the ones that live long enough to pass on these traits to their offspring.
<h3>What is natural selection?</h3>
The question is incomplete but I will try my best to explain the idea of natural selection.
The term natural selection refers to the idea put forward by Charles Darwin that organisms that posses favorable traits that enable them to survive in their environment are the ones that live long enough to pass on these traits to their offspring. This is also called the survival of the fittest.
Learn more about natural selection: brainly.com/question/2725702
First they minimize the size of their leaf to prevent evaporation, second they have big trunk that could hold a lot of water, and third they have this long root to search water
D, the black squirrels have survived because black has provided them with an advantage in this environment.
