Across
- 5. a phylum of aquatic invertebrate animals that comprises the sponges.
- 6. holes
- 7. microscopic structures of hard crystal material with fantastic shapes.
Down
- 1. a slender threadlike structure.
- 2. pumps water.
- 3. break down
- 4. cells that are found in connective tissue a biological organizational level between cells and a complete organ.