Across
- 2. Small arthropod with six legs
- 7. Mass of moving ice
- 8. Basic unit of matter
- 9. Cell that sends signals
- 11. Path of a celestial object
- 12. Large body of saltwater
- 15. Center of a cell
- 18. Large body orbiting a star
- 19. Mountain that erupts lava
Down
- 1. Preserved remains of organisms
- 3. Marine invertebrate with calcium skeleton
- 4. Symbiosis of fungus and algae
- 5. Force that pulls objects together
- 6. Group capable of interbreeding
- 7. Complete set of genes
- 10. Object that attracts iron
- 13. Solid with repeating pattern
- 14. Smallest unit of life
- 16. Microscopic living organism
- 17. Naturally occurring solid