Because they are born with them??? thats like asking someone why do they have eyes or ears etc.
Photosynthesis releases oxygen<span> into the atmosphere and cellular respiration uses the </span>oxygen<span> to </span>release energy from food<span>. The </span>process that releases energy from food molecules by producing ATP in the absence of oxygen<span>.</span>
Describes the relationship between an organism and its environment
Answer:
Inspiration
Explanation:
Pulmonary ventilation (breathing) can be defined as the flow of air into the lungs during inhalation (i.e., inspiration) and the inverse process where the air out of the lungs during exhalation (i.e., expiration). The lungs are active during the process of inspiration, while they are passive during expiration. Inspiration happens when the intrapulmonary pressure is below the atmospheric pressure, thereby the lungs expand and air enters the lungs.