Organisms are the biotic parts of an ecosystem.
Answer:
Explanation:
A gene can be turned on or off by environmental factors or from other cells that activate proteins known as transcription factors.
Answer: C. competition for nest sites between beetles and owls
Answer: Ectotherms depend on external heat sources. Their body temperature changes with the temperature of the environment. Endotherms generated heat internally to maintain body temperature.
Explanation: