Answer:D
Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.
B- Electron transport chain
Answer:
The arteries (red) carry oxygen and nutrients away from your heart, to your body's tissues. The veins (blue) take oxygen-poor blood back to the heart. Arteries begin with the aorta, the large artery leaving the heart. They carry oxygen-rich blood away from the heart to all of the body's tissues.
Explanation:
sorry if its wrong
Answer:
Intraspecific interactions, where they are the same species, or interspecific interactions, where they are from different species.
Answer:
Insulin
Explanation:
Not sure how to explain this further, as the function of the enzyme is explained fully in the problem lol. PM me if you want more details though!
