biology

Couplet Number

Statement Choices

Classification

1

a. Symmetry is irregular (neither bilateral or radial); aquatic; body structure without tissues or organs

Class Demospongiae

b. Symmetry is radial or bilateral

2

2

a. Radial symmetry, lacks a well defined head

3

b. Bilateral symmetry (similar right and left body halves, anterior head end and posterior tail end)

6

3

a. No spines or arms present

4

b. Spines or arms present

5

4

a. Barrel-shaped body, short tentacles at one end surrounding mouth, adults attached to a substrate

Class Anthozoa

b. Saucer-shaped, transparent body with thin tentacles, free floating

Class Scyphozoa

5

a. Five arms present, body surface knobby

Class Asteroidea

b. Many-spined animal, resembles a pincushion

Class Echinoidea

6

a. Animal has no apparent skeleton, or may have an exoskeleton (hard outer covering), or may have a shell; invertebrate

7

b. Animal has internal skeleton; vertebrate

16

7

a. No hard outer covering, no exoskeleton, or no shell; worm-like

8

b. Hard outer covering, exoskeleton, or shell; not worm-like

1 1

8

a. Body is segmented

Class Clitellata

b. Body is not segmented

9

9

a. Body long and tubular

Class Secernentea

b. Body flattened

10

10

a. Free living, aquatic, ribbon-like, smooth

Class Turbellaria

b. Endoparasites (live inside host); may look segmented

Class Cestoda

11

a. No jointed appendages

12

b. Jointed appendages

1 4

12

a. Soft body inside bivalve shell (hinged shell with 2 halves), no head

Class Bivalvia

b. Soft body, obvious head

13

13

a. May or may not have a shell; head with tentacles, small eye or eye spot

Class Gastropoda

b. Large head with tentacles and large eyes present

Class Cephalopoda

14

a. Two pairs of antennae, large claws often present

Class Crustacea

b. One pair of antennae or none, no large claws

15

15

a. Four pairs of legs, no antennae or wings

Class Arachnida

b. Three pairs of legs, wings present

Class Insecta

16

a. Fishlike, flattened body; appendages finlike not jointed

1 7

b. Not fishlike, body not flattened, appendages jointed or absent

18

17

a. Fish, scales on body do not overlap; skeleton of cartilage

Class Chondrichthyes

b. Fish, scales on body overlap; skeleton bony

Class Osteichthyes

18

a. Body covered by scales, zero or four legs

Class Reptilia

b. Body not covered by scales

1 9

19

a. Claws absent

Class Amphibia

b. Claws or nails present on toes; skin covered with feathers or hair

2 0

20

a. Feathered, claws present

Class Aves

b. Hair present

Class Mammalia