They are considered so because are the indispensable parts of the nature cycle.Without formation,decay cannot be possible and similarly,formation cannot be possible without decay.In addition to this,THEY ARE IN A CHRONOLOGICAL MANNER SET BY NATURE and that's why cannot be seperated and so together constitute the cycle of nature.
Answer:
In the entire solar system, the environment of planet earth is unique due to the presence of the atmosphere.
It is responsible for providing carbon dioxide and oxygen which are essential for the presence of life on earth.
Secondly, it helps in keeping the earth warm through the greenhouse effect.
It prevents the entry of harmful radiations of the sun into the atmosphere.
Answer:
D) Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species.
Explanation:
The competitive exclusion describes relationship between two species that compete for the limiting sources, and cannot coexist. It is enough for one species to have slightly advantage to be dominant over the other. As a consequence, other species (the weaker one) will be extincted (shift to a different ecological niche).