The concept of the struggle for existence<span> concerns the competition or battle for resources needed to live. It can refer to human society, or to organisms in nature. The concept is ancient, and the term </span>struggle for existence<span> was in use by the end of the 18th century. From the 17th century onwards the concept was associated with a population exceeding resources.
Hope this helped!
STSN</span>
<span>True. Plants get their energy from the sun, and we get ours from plants and animals in which they all live in environment. </span>
I believe it is oxygen and carbon dioxide
Two intermediates of the sterol biosynthesis pathway, isopentenyl diphosphate and dimethylallyl diphosphate, are used by archaea in the biosynthesis of isoprenoids. Isoprenoids are organic compounds <span> which play widely varying roles in the physiological processes of plants and animals.</span>