How do the organs and systems of an animal facilitate the creature's carrying out each of the characteristics of life mentioned in the first unit: cellular structure and function, reproduction, metabolism, homeostasis, heredity, adaptation and evolution, and interdependence.

Homeostasis, Reproduction, and Metabolism are all the consequence of various organs imparting and arranging in a way that takes into consideration the detail of specific cells to do certain things. Since we have such a variety of organs to do diverse things, the cells can concentrate on doing one capacity rather than one cell doing the greater part of the capacities we can do today. We advanced from single cell creatures into what we are today through a large number of years of adjustment and the passing on of qualities that are the best fit for the earth. Creatures are the consequence of a huge number of years of cooperation from cells to make this extreme being that is us.