a. Reproducing
f. obtaining energy
d. maintaining structure
Why do these three illustrate the great challenge for every species.
1. Reproduction, is as vital for an entire race to survive. It prolongs their generation onwards and offspring to the next centuries to pass by.
2. Obtaining energy. In both humans and animals, even plants is a challenge because these creatures need to work in order to obtain these need resource from food –preys.
3. Maintaining structure. For the living organisms to still exist they need to keep themselves intact. Combating diseases and having nutrition. This is a by-product of having energy.