Answer:
1. Biosphere
2. Cells
3. Organ system
4. Vital organs
5. Biotic
6. Tissue
7. Population
8. Ecosystem
9. Symbiosis
10. Circulatory system
-The circulatory system delivers oxygen and nutrients to cells and takes away wastes. The heart pumps oxygenated and deoxygenated blood on different sides. The types of blood vessels include arteries, capillaries and veins.
