<span>Organisms
that expend energy to regulate some or all of their internal conditions are
known as regulators. Regulators are organisms that can control their internal
environment regardless of external environmental change. Regulators achieve this
by homeostatic mechanisms and it requires a lot of energy. Examples of
regulators are mammals and birds</span>
Answer:
if we`ll not classify living beings then it`ll become difficult to study all of beings one by one. In order to make their study easier biologists have classified all living beings into five major groups.
Explanation:
B. The nervous system collects and responds to information about the external and internal environment.