8.2.A—Describe the strategies organisms use to acquire and use energy

Describe the strategies organisms use to acquire and use energy.

• Organisms use energy to organize, grow, reproduce, and maintain homeostasis.
  • i. Organisms use different strategies to r egulate body temperature and metabolism. Endotherms use thermal energy generated by metabolism to maintain homeostatic body temperatures. Ectotherms lack efficient internal mechanisms for maintaining body temperature, although they may regulate their temperature behaviorally by moving into the sun or shade or by aggregating with other individuals.
  • ii. A net gain in energy results in energy stor age, the growth of an organism, and increased reproductive output.
  • iii. A net loss of energy results in loss of mass, a decreas e in reproductive output, and, eventually, the death of an organism.
• Different organisms use various reproductive strategies in response to energy availability. Some organisms alternate between asexual and sexual reproduction in response to energy availability.