What kind of key cannot unlock a thing? Dichotomous Keys A dichotomous key is a tool that allows the user to determine the identity of items in the natural

What kind of key cannot unlock a thing?

A Dichotomous Key

Dichotomous Keys

• A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish.

• "Dichotomous" means "divided into two parts". Therefore, dichotomous keys always give two choices in each step.

1 With flower.Without flower

AngiospermsGo to 2

2 Seedless.Seed bearing

Go to 3Gymnosperms

3 Plant body do not differentiated into root,stem and leaves.Plant body differentiated into root, stem andleaves

Go to 4

Go to 5

4 Without photosynthetic pigment.With chlorophyll or other photosyntheticpigment

AlgaeFungi

5 No vascular tissues.With vascular tissues

MossesFern

Example of a dichotomous key…

Traditional format

Dichotomous key

N o n -flo w e rin g p la n ts

W ith o u t p h o tsyn -th e tic p ig m e n t

W ith c h lo ro p h yll o ro th e r p h o to syn th e ticp ig m e n t

A lg a e Fu n g i

N o v a sc u la r tissu e s

W ith va sc u la rtissu e s

M o sse s G ym n o sp e rm s

P la n t b o d y n o td iff e re n tia te d in toro o t, ste m a n d le a v e s

P la n t b o d yd iff e re n tia te din to ste m a n d le a v e s

Se e d le ss Se e d -b e a rin g

Fe rn s

F lo w e rin g P la n ts(A n g io sp e rm )

W ith o u t flo w e rW ith flo w e r

P la n ts

1a. With a hole Go to Question 2

1b. Without a hole Go to Question 3

2a. Six sided It is Species #1

2b. Four sided It is Species #6

3a. With threading Go to Question 4

3b. Without threading It is Species #8

4a. Pointy tip Go to Question 5

4b. No pointy tip Go to Question 6

5a. Rounded head It is Species #4

5b. Not rounded head It is Species #7

6a. Flat head Go to Question 7

6b. Not flat head It is Species #2

7a. Body length twice the width of head

It is Species #5

7b. Body length not twice the width of head

It is Species #3

Let’s Practice……..Which bird is the Certhidea?Which bird is the Platyspiza?Which bird is the Geospiza?Which bird is the Camarhynchus?

Guided Practice

Let’s Practice….. What is fish letter g? a?

GUIDED

PRACTICE

A. Beverlus B. Dallus C.Rajus D. Kentuckyus

E. Californus F. Walawala G. Dakotas H. Yorkius

Cooperative Group Practice- Complete Norms ID in crews.Answers to Dichotomous Key on Norms

REMEMBER- the objective is to work together to complete the task. Giving answers is to crew members is not acceptable. Help struggling crew members by showing them HOW to identify the Norm rather then by simply giveingthem the answer.

Dichotomous Key Independent Practice

Identify the fish using a dichotomous key. Teacher needs to hand out the

dry erase markers and white boards.

Now use the dichotomous key on your table to identify these fish

· Anterior-front· Posterior-rear

· Dorsal-top· Ventral-bottom

· Elongated-stretched out· Concave-bowed in (like the mark in the grass if you

drop a cannon ball)· Convex-bowed out

· Barbels- whiskers· Caudal-tail

Fish #1

Rock Bass (Redeye)

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Fish #2






Brook Trout

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Channel Catfish90603010

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Concave forehead






Yellow Perch

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This is a Mad Tom catfish. They only grow a few inches in length. They are NOT on the key….

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Fully grown 5 inch adult……..






Bluegill

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Bullhead Catfish

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SlightlyIndentedCaudal.






Chain Pickerel

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American Eel

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This is a Redbreast. It is NOT on the key ;)

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Largemouth Bass90603010

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Northern Pike

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Rainbow Trout

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· Elongated-stretched out· Concave-bowed in (like the mark in

the grass if you drop a cannon ball)· Convex-bowed out


White Suckah…Sucker….

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· Elongated-stretched out· Concave-bowed in (like the mark in the grass if you drop a cannon

ball)· Convex-bowed out


This is a Black Crappie (pronounce “Crop’-ee”) and it isn’t on the key…

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Carp

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Smallmouth Bass

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Walleye

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White Crappie

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This is a Bowfin or “Mudfish,” and it isn’t on the key….

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This is a Blue Catfish….

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Day Three

Opening/Closing-

Using your Pamishan Dichotomous Key homework sheet, identify this Pamishan.

Narrowus wolfus

Walk-thru example…

1. What tool is used to help identify and classify organisms?A dichotomous key.

2. How many options are there for each number in this tool?two

3. Use the Pamishan dichtomous key to determine which Pamishan is shown here.This is number 10, Broadus emmus.

Opening/Closing

Pamishan Creatures Activity OneIndependent Practice (OPTIONAL)-Each of you will be assigned a number for a Pamishan Alien and a dichotomous key (do NOT write on either one.) Use the dichotomous key to identify your Pamishan Alien.

Pamishan Creatures Activity TwoIndependent PracticeIdentify the Pamishan Aliens. OWs will use Crew Drill Tally sheet to record incorrect responses for each crew member (#1-10 only.) Boatswain will ensure answers are reported accurately.

Pamishan Alien Dichotomous Key answers

1. Narrowus portus2. Broadus archus3. Narrowus plainus4. Broadus hairyemus5. Broadus hairus6. Broadus anderscus7. Narrowus montanus8. Narrowus georgius9. Narrowus blankus10. Broadus emmus

11. Narrowus cyclops12. Broadus hairystus13. Narrowus beardus14. Broadus walter15. Broadus plainus16. Broadus kiferus 17. Narrowus starbops18. Broadus tritops19. Narrowus wolfus20. Narrowus fuzzus

Salamanders:

Use your handout to identify these salamanders

14

2

3

5

6

Independent PRACTICE

Over 7 cm.

Over 7 cm.

Siren

Spotted Salamander

Mudpuppy

MarbledSalamander

Tiger Salamander

Red-backed Salamander

1. A __________________ is a tool used to help identify and classify organisms.

2. What is this organism?This is number 1, Narrowusportus.

Opening/Closingdichotomous key

3. What is this organism?This is a two-linedSalamander.

Use the Pamishan key in the vinyl sleeve.

Use the salamanders key.

No external gills

Hind legs

Key will say spikes on left leg. That is YOUR left as you are looking at it.

Less than 7 cm.

Day Four

Find Arachnid Dichotomous Key

Microwhip Scorpion

A

Daddy Long Legs

•Segmented abdomen•No tail•Abdomen much larger than cephalothorax•Pedipalps much shorter than legs

B

Scorpion

C

Wind Scorpion

Segmented abdomen.Abdomen larger than cephalothorax.Pedipalps about the same size as legs.No pincers on pedipalps

Pedipalps

D

Mite

-no segmented cephalothorax or abdomen.-SpinesSize of a pencil point-

Cephalothorax and abdomen join here

E

Whip spiders

F

-Segmented abdomen-No tail-First leg

Tick

G

-no segmented abdomen or ceph.-no narrowing where abdomen and cephalothorax meet.

Sea Spider

H-segmented cephalothorax-abdomen much smaller than cephalothorax

Argiope

I

Cephalothorax

Abdomen (narrowing at waist)

tiny pedipalps

Abdomen NOT segmented

Some hair on cephalothroax but not on abdomen

Jumping Spider

J- NO segmented abdomen or cephalothorax-narrow “waist.”-pedipalps slightly shorter than legs

Curved pedipalps

TarantulaK

-Pedipalps straightNo segmented abdomen or ceph.-Narrow waist

Whip Scorpion

-no stinger on tip of tail.-large

pincers

pedipalps

L

Trapdoor Spider

Plated cephalothorax

Thick, tight jaws

pedipalps

M

Pseudoscorpion

pedipalps

Abdomen has more than 6 segments

Abdomen does not “split” or fork and does not have any kind of tail. Using the Insect Dichtomous Key to

identify the order of this insect.

Order Phasmatodea- Walking Stick

Eyes located on sides of head

Order Thysanura- Silverfish.

Using the Insect Dichtomous Key to identify the order of this insect.

Use the Dichotomous Key for Stream Animals to Identify

Mayfly Larva

Single hook on end of each appendage (leg)

Tails are “thin.”


Hellgrammite


Damselfly Nymph

Tails are “wide.”


Emerging from sand tube.

Caddisfly Larvae


Cranefly Larvae


Dragonfly Nymph Three short points, but no tails.

Use Seaworld Key

Use Seaworld Key

Use Cedar Glade Flowers Key

A “daisy-like” flower would be similar to this. Multiple, long, slender petals.

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What kind of key cannot unlock a thing? Dichotomous Keys A dichotomous key is a tool that allows the user to determine the identity of items in the natural