Algae

5. Ridge running along dinoflagellates that houses the transverse flagellum
9. Sporophyte and the male and female gametophytes are not morphologically identical
11. Body of a seaweed
12. Larger frustule
13. Phylum of green algae
15. Blade of a seaweed
16. Grove in dinoflagellates that houses the longitudinal flagellum
17. Attachment point of a seaweed
18. Enriched with nutrients

1. Cyanobacteria becoming part of a larger cell through vesicles
2. Smaller frustule
3. Glass outside of diatoms
4. Phylum of dinoflagellates
6. Phylum of diatoms and brown seaweeds
7. Bladder that keeps the thallus upright
8. Phylum of red algae
10. Sporophyte and the male and female gametophytes are morphologically identical
14. Meaning 'different flagellum'