Answer:
Stephen Stearns states that natural selection doesn't mean the survival of the fittest organisms, but rather this mechanism is illustrated by the selective reproduction of the fittest. Natural selection can be classified into distinct types, including directional, disruptive and stabilizing selection, which are in turn based on sexual selection. These types of selection are driven by different outcomes that have different dynamics.
This process is referred to as Ammonification, I believe, basically this allows Nitrogen to be in the appropriate form for plants to absorb it.
Variation means difference in genetic makeup between individuals within a specie.
Simple. exocine glands are found in the Adrenal. glands of dogs
