DICHOTOMOUS KEY OF LIVING ORGANISMS

KEY TO THE KINGDOMS

1. >Is made of one cell or less (usually you cannot see it without a microscope). Go to 2

>Is made of many cells that work together as one organism (usually you can see it without a

microscope). Go to 3

2. >The DNA is organized into a nucleus in the cell. Kingdom Protista. Go to Key to Protista Phyla

(#30). >The DNA is spread out throughout the cell. Kingdom Monera. STOP.

3. >Has Chloroplasts and cell walls (usually part of it is green) Kingdom Plant. Go to "Key to Plant Phyla

(#14)"

>No chloroplasts. Go to 4

4. >Has a mouth or body opening for ingesting its food and no cell walls. Kingdom Animal. Go to "Key

to Animal Phyla" (#5)

>No mouth. Has Hyphae or Rhyzoids (small strands of cells that look like hairs) that secrete enzymes to

break down food and then absorbs the nutrients though the cell membrane. Kingdom Fungi. STOP.

KEY TO THE ANIMAL PHYLA (If there is an asterisk (*) after the phylum name you must continue on the

"Key to Animal Classes)."

5. >No muscles (can’t move on its own) (two cell layers). Go to 6

>Has muscles (can move on its own) (three cell layers). Go to 7

6. >Has many body openings (holes), no one mouth. Phylum Porifera (sponges). STOP.

>One body opening (food goes in the same opening wastes come out), usually cup-shaped

Phylum Coelenterata (jellyfish, anemones, hydra) . STOP. 7. >One body opening (food goes in the same opening wastes come out), worm shaped, flat

Phylum Platyhelminthes (flatworms). STOP.

>Two body openings (food goes in one opening and wastes come out the other: mouth and anus) Go to 8

8. >Body is segmented (externally divided into sections). Go to 9

>Body is not segmented. Go to 10

9. Has an exoskeleton and jointed legs. Arthropoda Group* Go to Key to Animal Classes (#18)

>Worm Shaped and Soft body. Phylum Annelida (segmented worms). STOP.

10. >Has a spinal cord. Phylum Chordata* Go to Key to Animal Classes (#21)

>No spinal cord. Go to 11

11. >Ring of cilia around oral opening. Usually microscopic. Phylum Rotifera. STOP.

>No ring of cilia around oral opening. Go to 12

12. >Worm-shaped and Soft body. Simple body systems. Phylum Nematoda (round worms). STOP.

>Complex body systems. Not usually worm-shaped. Go to 13

13. >Spiny Skin, Radial Symmetry, Pentameric (divided into 5.s). Phylum Echinodermata. STOP.

>Soft body and muscle foot. Most forms have a shell. Phylum Mollusca* Go to Key to Animal

Classes (#27)

KEY TO THE PLANT PHYLA, CLASSES AND SUBCLASSES 14. >Has stems, roots and leaves that use tiny tubes to transport nutrients. Group: Tracheophyta Go to 15

>No stems, roots, and leaves. Transports nutrients by diffusion. Phylum Bryophyta (Moss). STOP.

15. >Reproduces with spores. Phylum Fillicinophyta (ferns). STOP.

>Reproduces with seeds. Go to 16

16. >Seed develops in a fruit, has flowers. Phylum Anthophyta (Angiosperm) (flowering plants) Go to

17

>Seed develops in a woody cone. Phylum Coniferophyta (Gymnosperm) (conifers). STOP.

17. >One seed part, Parallel veins in leaf, petals in 3’s. Class Monocotyledoneae (Monocot). STOP.

>Two seed parts, Branched veins in leaf, petals in 4’s or 5’s. Class Dicotyledoneae (Dicot).. STOP.

KEY TO SELECTED ANIMAL CLASSES (Arthropoda, Mollusca, and Chordata)

Key to Arthropoda Classes:

18. >2 or 3 body sections, 10 or less legs. Go to 20

>More than 3 body sections, more than 10 legs. Phylum Mandibulata Class Myrapoda Go to 19

19.>2 pair of legs on each segment. Order Diplopoda (millipedes). STOP.

>1 pair of legs on each segment. Order Chilopoda (centipedes). STOP.

20. >6 legs . Phylum Mandibulata Class Hexapoda (Insecta). STOP.

>8 legs. Phylum Chelicerata Class Arachnida (spiders, ticks). STOP.

>10 legs, sometimes claws. Phylum Crustacea. STOP.

Key to Chordata Classes

21. >Hair or feathers, 4-chambered heart, warm-blooded. Go to 23

>No Hair or feathers, 2 or 3 chambered heart, cold-blooded. Go to 22

22. >Smooth, Moist skin, Lay eggs in water. Class Amphibia. STOP.

>Has scales. Go to 24

23. >Has Hair, Nurses young with Mammary glands, Live birth. Class Mammalia. STOP.

>Has Feathers, Egg Birth. Class Aves (birds) STOP.

24. >Hard, Dry Scales, Breath with lungs, Lay eggs on land. Class Reptilia. STOP.

>Fish-like scales. Breath without lungs. Go to 25

25. >Jaws. Go to 26

>No Jaws. Class Cyclostomata. STOP.

26. >Skeleton made of bone. Class Osteichthyes (fish). STOP.

>Skeleton made of cartilage. Class Chondrichthyes (sharks and rays). STOP.

Key to Mollusca Classes

27. >No Tentacles. Go to 28

>Has Tentacles with suckers, well-developed eye. Class Cephalopoda (head-foot). STOP.

28. >2 shell parts or less. Go to 29

>More than two shell parts. Class Polyplacophora (many shells)

29. >2 shell parts Class Bivalvia (clams). STOP.

>1 shell (some forms have no shell) and crawls on stomach with specialized "foot". Class Gastropoda

(stomach-foot)(snails and slugs). STOP.

Key to Protista Phyla

30. >Pseudopodia. No definite shape Phylum Sarcodina STOP.

>Has Flagella or Cilia Go to31.

31. >Has Flagella Phylum Flagellata STOP.

>Has Cilia Phylum Ciliophora) STOP.

Dichotomous Key Answers 2014

Kingdom Phylum Class Order

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

TAXONOMIC IDENTIFICATION CHARACTERISTICS

FOR THE CLASSIFICATION OF LIVING THINGS (11/5/04) Use the Dichotomous Key to Identify the Kingdom, Phylum, Class, and Subclass of the following organisms: Remember: if the key does not instruct you to "Go to ..." then you must stop.

Use the following chart form (there are 33 organism descriptions)

ORGANISM DESCRIPTIONS: All descriptions are for many-celled organisms except where designated "one cell." If the part is not listed then the organism doesn't have it.

1. Seeds in cones

Chloroplasts,

Cell Wall of Cellulose

Stems, Roots, Needles

2. One body opening

2-Layer Gastrula

Ingests food

3. Stems, Roots, Leaves

Chloroplasts,

Cell Wall of Cellulose

Spores

4. One cell

Chromosomes (DNA) in

nucleus

Has Flagella

5. Spores

Chloroplasts,

Cell Wall of Cellulose

Grows low to ground

No stems, roots, leaves

6. Spores in "Cap"

Hyphae or Rhyzoid

No stems, roots, or

leaves,

Cell Wall of Chitin

No Chloroplasts

7. Seeds in Fruits

Branched veins

Two part seeds

Stems, Roots, Leaves

Chloroplasts

Cell Wall of Cellulose

8. Ingests food

Many body openings (no

one mouth)

2-Layer Gastrula

9. Mouth and Anus

3-Layer Gastrula

Digests food internally

Worm-shaped

simple body systems

Not segmented

10. Digests food internally

Three body segments

3-Layer Gastrula

Exoskeleton, jointed legs

Three pairs of legs

Mouth and anus

11. Chloroplasts

Stems, Roots, Leaves

Cell Wall of Cellulose

One part seed, Parallel

Veins

Seeds in a fruit

12. Mouth and Anus

3-Layer Gastrula

Digests food internally

Cilia around mouth

simple body systems

Not segmented

13. 3-Layer Gastrula

Mouth and anus

Ingests food

Not segmented

Hair

Spinal Cord

14. Segmented

Worm-shaped

Ingests food

Soft body

3-Layer Gastrula

Mouth and anus

15. Ingests food

Spinal Cord

Not segmented

Feathers

3-Layer Gastrula

Mouth and anus

16. Scales and lungs

3-Layer Gastrula

Not segmented

Spinal Cord

Lays leathery eggs on land

Mouth and anus

17. Two shells

Ingests food

Soft body, 3-Layer Gastrula

Muscle foot

Mouth and anus

No spinal cord

Complex body systems

18. Ingests food

3-Layer Gastrula

Two body openings

Not segmented

Spinal cord

Scales, no lungs

No jaws

19. Exoskeleton

Ingests food

3-Layer Gastrula

Two Body Openings

Five pairs of legs

Two Body Segments

No Spinal cord

20. No Spinal Cord

3-Layer Gastrula

Ingests food

Four Pairs of Legs

Exoskeleton

Two body Segments

Mouth and anus

21. 3-Layer Gastrula

Ingests food

Mouth and anus

Exoskeleton

Many body segments

Two pairs of legs per segment

More than 3 segments

22. Ingests food

Two body openings

Not segmented

Spiny Skin

3-Layer Gastrula

No Spinal Cord

Complex body systems

23. 3-Layer Gastrula

More than 3 segments

Mouth and anus

Exoskeleton, jointed legs

Many body segments

Digests food internally

One pair of legs on each

segment

24. Jaws

Ingests food

Not segmented

Scales, no lungs

Bone Skeleton

3-Layer Gastrula

Spinal Cord

Mouth and anus

25. Soft body

Not segmented

3-Layer Gastrula

No Spinal cord

Tentacles with suckers

Two body openings

Ingests food

Not worm-shaped

Complex body systems

26. Ingests food

3-Layer Gastrula

Not Segmented

Spinal Cord

Scales, no lungs

Cartilage Skeleton

Jaws

Mouth and anus

No hair or feathers

27. Backbone (spinal cord)

Smooth, moist skin

3-chambered heart

Digests food internally

Mouth and Anus

Lays Eggs in water

3-Layer Gastrula

Not segmented

Not worm-shaped

28. One shell

Crawls on stomach

Ingest food

Soft body, 3-Layer Gastrula

Muscle foot

No spinal cord

Mouth and anus

Not worm-shaped

Complex body systems

29. One cell

Chromosomes (DNA) spread out

30. One cell

Chromosomes (DNA) in

nucleus

Has Cillia

31. 3-Layer Gastrula

Ingests food

One body opening

Flat

32. One cell

Chromosomes (DNA) in

nucleus

Has Pseudopodia

33. Many shells

Crawls on stomach

Ingest food

Soft body

3-Layer Gastrula

Muscle foot

No spinal cord

Mouth and anus

Not worm-shaped

Complex body systems