| A | B |
|---|
| Invertebrates | Animals that lack a backbone |
| Vertebrates | Animals that possess a backbone |
| Nematocysts | Small capsules that contain a toxin which is injected into prey or predators |
| Posterior end | The end of an animal that contains the tail |
| Hermaphroditic | Possessing both the male and female reproductive organs |
| Mantle | A sheath of tissue that encloses the vital organs of a mollusk, secretes its shell, and performs respiration |
| Univalve | An organism with a single shell |
| Bivalve | An organism with two shells |
