Answer:
a.
Explanation:
Engery is the driving force of the oxygen cycle is photosynthesis itself, which is responsible for the creation and maintenance of earth's atmosphere.
C- pitches in because it pinched the plasma membrane
The main function of the respiratory system is to allow the exchange of gases between the atmosphere and the lungs.
Hence,the only structure that carries out this function is the alveoli as other structures such as the nose,trachea and pharynx transport gases to the alveoli just so that it can can out its function.
A unicellular organism must perform all functions necessary for life. A multicellular organism has specialized cells, tissues, organs, and organ systems that perform specific functions.
Answer:
Carbohydrate digestion starts in the mouth and protein digestion starts in the stomach.The digestive system fuels the cells and the excretory system rids the body of the cells' waste.
Explanation:
