a specialized cell, group of cells, or organ of endothelial origin that selectively removes materials from the blood, concentrates or alters them, and secretes them for further use in the body or for elimination from the body — compare endocrine gland, exocrine gland.
Answer:
The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion. ... While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.
Explanation:
The two substances that scientists use are
carbon-14 and carbon-12
1.
the Changes of the Human Bodies
2. Shapes Different Careers
3. Provides Answers to Large-scale Problems
4. Teaches Concepts on Basic Living
5. Helps in Answering the Fundamental Questions About Life
6. Have another for (good luck) Paves Way for Scientific Investigations
From my speculation it is loss of habitat and global warming
