true. theories can be modified
Not sure what is going on here if u put a picture in next time that would help a lot sorry
Answer:
The answer to this question is given below in this explanation section.
Explanation:
"advantages of interconnecting air sacs for birds"
The air sacs permit a unidirectional flow of air through the lungs.Unidirectional flow means that air moving through birds lungs is largely fresh air and has a higher oxygen content.In contrast air flow is bidirectional in mammals moving back and forth into and out of the lungs.As a result air coming into a mammals lung is mixed with old air has less oxygen. so in bird lungs,more oxygen is available to diffuse into the blood(avian respiratory system).
- The air sacs are thin membrane structures connected to the primary or secondary bronchi via ostia and they comprise most of the volume of the respiratory system.
- Air sacs are poorly vascularized by the systemic circulation and do not directly participate in significant gas exchange but act as a bellows to ventilate the lungs.In most species,there are nine air sacs which can be considered in cranial and caudal functional groups.
- The cranial group consists of the paired cervical air sacs,the unpaired clavicular air sacs and the paired cranial thoracic air sacs.
Solar because the sun gives radiant energy to plants to make food which makes oxygen in the process. animals eat the plants to get energy and the food chain goes on. With out the plants turning the sun into food then we wouldn't be around.