Final answer:
A bear belongs to the Kingdom Animalia, and all organisms, whether multicellular like bears or unicellular, must exchange matter with the environment to grow, reproduce, and sustain their organization.
Step-by-step explanation:
The taxonomic classification system is a hierarchical system used for classifying and organizing organisms into categories based on shared characteristics. The most broad category is the Kingdom, which divides organisms into large groups such as Animals, Plants, Fungi, etc. For instance, the Kingdom category that best describes a bear is Animalia: Multicellular organisms that get their energy through ingesting other organisms.
Organisms are complex structures ranging from single-celled forms to highly organized multicellular entities. Their existence is characterized by the requirement to exchange matter with the environment to fulfill activities such as growth, reproduction, and maintaining organization. When considering living forms such as moose, bears, or even plants, each is an example of an organism that must engage in this continual exchange to sustain life.
Multicellular organisms like bears have specialized receptors for signaling, while single-celled organisms often communicate through direct membrane fusion with adjacent cells. The complexity of biological organization is evident when considering the structural hierarchy from an entire organism down to the level of molecules.