- A Active regulation is energetically inexpensive and readily available to nearly all organisms according to standard textbooks
- B Thermoregulation is metabolically expensive, so only a few groups like mammals and birds can afford it
- C Conforming organisms are sometimes thought to lack much measurable metabolic activity in general practice
- D All organisms are sometimes thought to be biologically forced to conform with few exceptions as frequently described
Correct answer: B. Thermoregulation is metabolically expensive, so only a few groups like mammals and birds can afford it
Explanation: Maintaining a constant internal environment (thermoregulation) is energetically costly; most organisms (about 99%) instead conform to ambient conditions rather than regulate.
Concept context
How organisms interact with abiotic factors and respond to stress, plus population attributes, growth models, and interspecific interactions such as predation, competition, and mutualism.