INVERTEBRATES (I)

3. Body plan in which only a single, imaginary line can divide the body into two equal parts
6. Marine annelids move with the help of these
7. Class that includes squid, octopuses and nautiluses
12. Organ of terrestrial annelids that helps in reproduction
13. A group of invertebrates including earthworms and leeches
14. Invertebrates don't have this system, but we do!
15. Most invertebrates undergo this process to convert into adults
21. Body plan in which body parts repeat around the center of the body
22. Not the biggest but the most intelligent of all invertebrates
23. Phylum in which sponges belong to
24. Skeleton of a sponge is made of these
25. A group pf invertebrates including 80% of animal species

1. Molluscs with divided shell and no head
2. Phylum which coral, jellyfish and sea anemone belong
4. Annelids have long tube-like body with many...
5. Free swimming cnidarian that is an umbrella like shape with hanging tentacles
8. A large opening on a sponge through which filtered water is expelled
9. One of two body of a Cnidarian
10. Most simple of all animals
11. Hole through which water enters and leaves a sponge
16. Bivalves lack this
17. Soft body invertebrates with an external shell
18. Nematodes have round body, simple systems and many are...
19. Class that includes sea snails and sea slugs
20. Long, soft and skinny animal with no legs (in general)