Exercise 5

2. The scientific name of the infra-phylum of cylindrical jawless fishes.
7. The scientific name of jawed fishes that possess a skeleton made entirely of cartilage.
8. The dorsal body wall of a mollusc that hides the visceral body part.
11. The scientific name of exclusively marine molluscs characterized by a bilateral symmetry, a prominent head and a set tentacles or arms.

1. Hard diamond shaped scales.
2. The genus of the honey bee.
3. A rear orifice, in some vertebrates, that serves as the only opening for the digestive, reproductive and urinary tracts.
4. The scientific name of a super-class which includs all limbed vertebrates.
5. The scientific name of a phylum of aquatic animals with pentaradial symmetry.
6. Worm blooded vertebrates characterized by the possession of feathers.
9. Vertebrates characterized by a unique shell.
10. They are distinguished by their limbless and greatly elongated body. The left lung is small or absent at all.