Answer:
1. Ends of the respiratory branches are called alveoli.
2. C. To control blood flow to different areas of the body depending on activities
Explanation:
1. The trachea divides into left and right primary bronchi which in turn divide multiple times upon entering the lungs and make the bronchial tree.
The final branches of the bronchial tree are the terminal bronchioles that lead to alveoli. The alveoli are the balloon-shaped structures and serve as the site of gas exchange between the blood and inhaled air.
2. The opening and closing of sphincters of capillary beds regulate the direction of blood flow. The opening of sphincters allows the blood to flow into associated branches of capillary beds while closed sphincters direct the blood from arterioles to venules via thoroughfare channel.
This local change in blood flow is responsible for the autoregulation of blood flow to different tissues to match their respective metabolic demands. For example, during physical activity, more blood is directed to skeletal and cardiac muscles.
Answer:
78 percent
Explanation:
The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.
Answer:
D. The statement is inaccurate because humans would not be able to distribute the product of nitrogen fixation from industrial processes in the same way that bacteria are able to distribute it globally now.
Explanation:
Nitrogen fixing bacteria has the responsibility in nature to trap and fix atmospheric nitrogen in ecosystems. They are very important components of the nitrogen cycle and play an important role in maintaining the balance of nutrients in nature.
If humans discover industrial processes to fix nitrogen, the process will be unsustainable in the long run if nitrogen-fixing bacteria ever go extinct because humans would not be able to distribute the product of nitrogen fixation from industrial processes in the same way that bacteria are able to distribute it globally now across several ecosystems all over the world.
Answer:
Because this person exists
Explanation:
