Cells

2. A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
3. A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles
4. Single-celled organisms that lack a nucleus; prokaryotes
5. An organelle found in plant and algae cells where photosynthesis occurs
7. Group of similar cells that perform a particular function
8. A jellylike fluid inside the cell in which the organelles are suspended
10. The basic unit of structure and function in living things
11. An organelle containing digestive enzymes
12. A type of leukocyte that surrounds and kills invading cells
13. Thin, flexible barrier around a cell; regulates what enters and leaves the cell
17. A nerve cell; the basic building block of the nervous system
18. Powerhouse of the cell, produces ATP

1. Cell that does not have a nucleus or other membrane-bound organelles
2. Strong, supporting layer around the cell membrane in some cells
6. Group of organs that work together to perform a specific function
9. An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells
10. Fundamental concept of biology that states that all living things are composed of cells
14. Organelle that makes proteins
15. Group of tissues that work together to perform closely related functions
16. A eukaryotic organism that cannot be classified as an animal, plant, or fungus