Final answer:
Organ tissue, especially the brain, typically has the highest priority for nutrient utilization in living animals due to their high metabolic activity and critical role in maintaining homeostasis.
Step-by-step explanation:
The question of which tissue has the highest priority of nutrient utilization in living animals is tied to the basic biological principle that different tissues have different energy and nutritional demands depending on their function within the body. Generally speaking, organ tissue, particularly the brain, is given the highest priority for nutrients to maintain homeostasis and essential bodily functions. Organs such as the brain are highly metabolically active, requiring a constant supply of energy from nutrients, typically in the form of glucose, to function correctly and support the overall well-being of the animal. The brain alone uses a substantial amount of the body's energy; for instance, in humans, it accounts for about 20% of total energy expenditure, despite making up only 2% of body weight.
Muscle tissue is also a significant site of energy utilization, especially during exercises when muscles are active, and energy demand is high. In contrast, adipose tissue and bone tissue have lower immediate metabolic demands but play crucial roles in longer-term energy storage and structural support, respectively. Thus, while all tissues need nutrients to survive, the urgency of that need varies depending on the role of the tissue involved.