Final answer:
An apple on a tree is nonliving because it does not fulfill all the characteristics necessary to be considered a living thing, such as maintaining homeostasis or reproducing on its own.
Step-by-step explanation:
An apple on a tree is considered nonliving although it is part of a living organism— the apple tree. To be classified as a living thing, an object must display several characteristics, among which are the abilities to respond to the environment, to grow and develop, to reproduce, to maintain homeostasis, to have complex chemistry, and to consist of cells. While an apple can grow and has complex chemistry, it does not itself maintain homeostasis, consist of cells in a way that supports independent life, or have the ability to respond to the environment or reproduce on its own.
Biologists would agree that two important traits necessary for life are cellular organization and the ability to reproduce. For example, a crystal might grow and maintain a regular structure which can mimic order, and a fire can spread, which might seem like reproduction, but neither are considered alive because they do not fulfill all of the seven traits necessary to be considered living.