Fish poop.
Tropical white beaches get their pearly white color from the excrement of fish far off of the coast which eat coral and other things that reside on the ocean floor. When they eat they swallow some sand into their mouths as well, and process it with the food they just ate. Their stomachs can't really digest the sand, tiny minute rocks essentially, and thus turn their color white. Or the rock forming the sand can be naturally pigmented a whitish tone as well.
Answer:
Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others.
The answer is; E
With environmental changes, the carrying capacity can either increase or decrease. It is important to note that the carrying capacity is the number of individuals of a species that a habitat can sustain indefinitely. With favorable environmental conditions, the carrying capacity increases while unfavorable environmental conditions decrease the carrying capacity.
I can’t answer how lichens arrive in a barren landscape but I can answer the 2nd part
Lichens grow when exposed to water. When wet, lichens begin to photosynthesize.
The clear and colourless fluid that surrounds cells and protein fibres in connective tissues is called Ground substance
