They come from the atmosphere, since plants use carbon dioxide to produce carbohydrates :)
Answer:
Well one of the first changes it the tadpoles start growing legs. Then it will continue to grow, changing and changing as it goes. Then it will start to live on land, and it will live on land as a tiny frog until it is completely grown up.
The correct answer for the given question above would be option A. The two organ systems that regulate homeostasis in our bodies are nervous and endocrine. The nervous system is responsible in the coordination of different systems in the body, including the voluntary and involuntary function. Whereas, the endocrine system, along with the nervous system is responsible for the regulation of different hormones that are responsible for different functions in the body.
A biological community with organisms interacting within their environment :)