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# Dichotomous Keys

Dichotomous Keys. What if we find things we don't know and we want to know what they are?. What’s my name !?. We use something’s characteristics in a similar way using…. Dichotomous Keys.

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## Dichotomous Keys

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1. Dichotomous Keys

2. What if we find things we don't know and we want to know what they are? What’s my name !? We use something’s characteristics in a similar way using…

3. Dichotomous Keys • A dichotomous key is a tool that allows the user to determine the identity of items in the natural world based on the items characteristics • "Dichotomous" means “divided into two parts” Greek origin • dichotomous keys always give two distinct choices in each step, often they are opposites • Black/white; good/evil; pointed/rounded

4. How to use a dichotomous key? HA! HA! Dichotomous Keys

5. How to use a Dichotomous Key? Here are creatures we don’t know! Lets choose one

6. How to use a Dichotomous Key? Choose only one creature at a time.

7. How to use a Dichotomous Key? Read steps 1a and 1b Decide which statement is true 1b is true

8. How to use a Dichotomous Key? Then follow the directions after that step. Go to step 5!

9. How to use a Dichotomous Key? At choice 5, you make another dichotomous choice 5a is true Go to step 6!

10. How to use a Dichotomous Key? Keep going until you come to a step that gives you the creature’s name. 6 a. The creature has one antennae Go to Step 7. C

11. How to use a Dichotomous Key? Choose a new creature and start at step 1a and 1b again. Continue until you find the creature’s name. C Where do you start Again?

12. Then, find the names of all the creatures

13. 1. a. wings covered by an exoskeleton – go to step 2 b. wings freely observed – Go to step 3 2. a. body has a round shape ……….ladybug, a red beetle with black spots b. body has an elongated shape ……….grasshopper, a green insect that hops 3. a. wings point out from the side of the body ……….dragonfly, an insect that is 10- 15 cm long and lives in marshes b. wings point to the posterior of the body ……….housefly, a flying insect with red eyes and an annoying buzz

14. Dichotomous key • the dichotomous key can also be expressed in a diagram form

15. Dichotomous key Another Example of a dichotomous key…

16. d Species D Species A Species B Species C d

17. Sphynrna mokarran

18. 4 legs Dog Spider 8 legs Live in Water Fish Lives on Land Worm

19. What do I do? • Title in your journal: • Dichotomous Key Practice • -3 Practice Problems in Back • 1.Bees • 1. • 2.Species E • 3. • 4.Species F • 5. • 6. • 2. Write your own- • 3. Name of shark?

20. Clear your desks, except for journals and pen/pencil!!!!!!!(the longer you take, the more of a chance you will have to complete your booklet at home!) • If you were absent yesterday: • Take 2 pages of copy paper. • Fold into Booklet (hamburger) • Staple binding (when you get to the back) • Title the cover page: Plant Booklet • You will have 3 minutes in the back of the room to draw your favorite type of plant (trees, flowers, bushes, etc.) • Number and Title Each Page!!!!!! • Page 1…Title….Seeds • Page 2 Title: Gas Exchange and Photosynthesis • Page 3 Title: Leaf adaptations • Page 4 Title: Leaf Structures • Page 5 Title: Tropisms • Page 6 Title: Flower Reproduction

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