Across 1. an organelle within the nucleus that produces ribosomes 3. an organelle formed by the centriole 5. an organelle unique to animal cells involved in cell replication 7. a rigid structure located on the outside of plant cells 10. large membrane-bound space in the cytoplasm of plant cells 13. composed of phospholipds, proteins, carbohydrates and cholesterol 17. nonmembrane-bound organelles in the nucleus where proteins are assembled 18. a series of highly folded membranes that is studded with ribosomes 19. the site of aerobic cellular respiration 20. hollow cylinders made of protein that provide structural support 21. a gel like fluid that suspends the cell's organelles Down 2. a series of highly folded membranes involved in the production and storage of lipids 4. flattened tubular membranes that packs proteins 6. a membrane that separates the nucleus from the rest of the cell 8. an organelle that contains digestive enzymes and breaks down foreign particles and wastes 9. small membrane-enclosed sac that stores and transports substances 11. manages cellular functions and contains DNA 12. thinnest filaments found in eukaryotic cells (made of actin) 14. an organelle unique to plant cells that is green in colour 15. a complex combination of DNA, RNA, and protein that makes up chromosomes 16. allow transport between the cytoplasm and nucleoplasm