Category |
Couplet |
Target |
1. | a. Irregular-shaped body; structure with many pores | Porifera |
b. Regular-shaped body (with right and left halves or a cylindrical shape | 2 | |
2. | a. Radial symmetry (disk-shaped or barrel-shaped) | 4 |
b. Bilateral symmetry (similar right and left body halves) | 3 | |
3. | a. Animal has internal skeleton | 19 |
b. Animal has external skeleton or no apparent skeleton | 6 | |
4. | a. Body hard, arms extend from a central disk, or spines present | 18 |
b. Soft body; little or no color | 5 | |
5. | a. Saucer-shaped transparent body with small tentacles | Class Scyphozoa |
b. Barrel-shaped body, tentacles at one end | Class Anthozoa | |
6. | a. Hard outer covering | 10 |
b. No hard outer covering | 7 | |
7. | a Body flattened | |
b Body not flattened | ||
8. | a. Smooth, nonsegmented body | Class Trematoda |
b. Apparently segmented, flattened body | Class Cestoda | |
9. | a Nonsegmented | 11 |
b Segemented body | Phylum Annelida | |
10. | a. Body has jointed legs | 14 |
b. Body inside shell is soft, has no jointed legs | 13 | |
11. | a. Tentacles or other appendages present | 12 |
b. Body long and tubular, no appendages | Phylum Nematoda | |
12. | a. Appears as a snail without a shell | Class Gastropoda |
b. Tentacles and eyes present | Class Cephalopoda | |
13. | a Bivalved shell (two halves) | Class Bivalvia |
b Univalved shell (single unit) | Class Gastropoda | |
14. | a. Jointed appendages on most body sections | 15 |
b. Jointed appendages on certain body segments; not all appendages are legs | 16 | |
15. | a. One pair of legs per body segment | Class Chilopoda |
b. Two pairs of legs per body segment | Class Diplopoda | |
16. | a. Two pairs of antennae, large claws often present | Class Crustacea |
b. One pair of antennae or none, no large claws | 17 | |
17. | a. Four pairs of legs, no antennae or wings | Class Arachnida |
b. Three pairs of legs, wings present | Class Insecta | |
18. | a. Arms present, body surface knobby | Class Asteroidea |
b. Many-spined animal, resembles a pincushion | Class Echinoidea | |
19. | a. Fishlike, flattened body, appendages finlike not jointed | 20 |
b. Not fishlike, body not flattened, appendages jointed or absent | 21 | |
20. | a. Scales on body to not overlap, skeleton of cartilage | Class Chondrichthyes |
b. Scales on body overlap, skeleton bony | Class Osteichthyes | |
21. | a. Body covered by scales, zero or four legs | Class Reptilia |
b. Body not covered by scales | 22 | |
22. | a. Claws absent | Class Amphibia |
b. Claws or nails present on toes, skin covered with feathers or hair | 23 | |
23. | a Feathered, claws present | Class Aves |
b Hair present | Class Mammals | |