The absorption and distribution of materials within an organism is a life function known as nutrition.

Here's why:

* Absorption: This involves taking in nutrients from the environment. In animals, this primarily happens in the digestive system, while plants absorb nutrients through their roots.

* Distribution: This involves transporting absorbed nutrients to various parts of the body. This is handled by the circulatory system (blood in animals, vascular system in plants).

While other life functions contribute to this process (like digestion, circulation, and respiration), nutrition encompasses the overall process of acquiring and delivering essential materials for growth, maintenance, and energy production.