Cells and Body Systems

5. Organelle that directs all the activities in a cell.
7. Made of just one cell.
9. Organelles that converts sunlight into food.
10. poisonous substance converted from highly toxic ammonia by the liver.
11. Tissue of the brain, spinal chord, and nerves.
12. The basic unit of life.
13. Tiny blood vessels that connect arteries to veins.
14. Living things.
15. diffusion of water through a selectively permeable membrane.
21. Supplies blood with oxygen from the outside air and removes carbon dioxide.
24. Contents of the cell inside the cell membrane excluding the nucleus.
25. Blood vessels that return blood from the body to the heart.

1. Outer covering of a cell that provides strength and support.
2. Group of tissues that work together to perform a specific function.
3. Specialized cells of the nervous system that receive and transmit information.
4. Transport system reaching every cell in the body, delivers nutrients.
6. Usually unicellular organisms that can be seen only through a microscope.
8. Organelle that directs all the activities in a cell.
16. Breaks down the food you eat into parts small enough to be absorbed and transported throughout the body.
17. Removes chemical and gaseous waste from the body.
18. Blood cells specialized to fight infection.
19. Tubes that connect the bronchi to the air sacs in the lungs.
20. Coordinates and controls all organs and organ systems.
22. Two main branches of the trachea that lead into the lungs.
23. Small finger like projection on the inner surface of the small intestine that absorbs nutrients.