Dichotomous Key and intro notes of living thing.ppt

classification

1. Classification:
Using Dichotomous
Keys

2. Have you ever wondered
what some plant or some
animal was called?
There have been over 1 million species
identified and named (classified) on
earth. (Though scientists estimate that
there are somewhere between 10-100
million species on earth.)
We can’t possibly memorize all of them
so we rely on keys made by specific
experts to identify them.

3. For ex: What if we have little
knowledge of these organisms?
The Genus name of typical bird/reptile specimens…
Anas
GallasElaphe
Malaclemys
Anolis
?
?
?
?
?

4. Dichotomous Key
A dichotomous key uses a series
of paired questions to identify
previously classified/named
organisms

5. Dichotomous Key
The Genus name of typical specimens…
1.a) It has feathers …………… Go to 2
b) No feathers…………… Go to 3
2.a) It has webbed feet………… Anas
b) No webbed feet…….….... Gallas
3.a) It has legs……………………Go to 4
b) No legs…………………….. Elaphe
4.a) It has a “shell” …………….. Malaclemys
b)No shell………………………. Anolis

6. Your turn!
1)Use a typical dichotomous key to
identify the common name of the
Arizona fish species pictured.
2)Become an expert and make your
own dichotomous key for the given
“organisms”.

7. Classification of Life
Journal Notes

8. Classification
grouping organisms in a logical
manner.

9. Taxonomy
Grouping method based on:
 Anatomy
 DNA and proteins
 Evolutionary relationship
 Developmental similarities

10. Important People
Aristotle (300 B.C.)
life: “Plant” or “Animal”.
Carl Linnaeus (1750s)
Grouped based on morphology
Came up with 7 levels of Taxonomy
We now use 8 levels

11. How to Classify
an Organism
Eight Major “taxa” or groups.
1.Domain
2.Kingdom
3.Phylum
4.Class
5.Order
6.Family
7.Genus
8.Species

12. Scientific Names
2 word scientific name.
Uses Latin
Binomial Nomenclature – “two name
naming list”.
Genus species
How is it written?
Homo sapiens

13. Examples
Scientific Name
Felis domesticus
Panthera leo
Canis lupus
Canis lupus
familiaris
Common Name
House cat
Lion
Wolf
Domestic dog

14. Example: Humans
Domain =
Kingdom =
Phylum =
Class=
Order=
Family =
Genus =
Species =
Eukarya
Animalia
Chordata
Mammalia
Primates
Hominidae
Homo
sapiens

15. Assignment:
Arizona Animal classification
assignment. Due Monday. You will
present your animal to the class.
Please be prepared.

16. Classification of Life
Journal Notes Continued

17. Classification Today
Organisms are grouped based on evolutionary
relationships
Cladogram: Diagram that shows the evolutionary
relationships among organisms

18. Taxonomy Today
Based on:
Homology – Organisms with
similarly evolved structures are
grouped together.
Molecular Biology – Organisms
with similar DNA are grouped
together.

19. Valid Cladograms:
Show evolutionary relationships
CLASSIFICATION BASED ON
ANALOGOUS STRUCTURES Cladogram – Based on
Homology
Appendages
Conical Shells
Crab
Barnacle
Limpet Crab
Barnacle Limpet
Crustaceans Gastropod
Molted
exoskeleton
Segmentation
Tiny free-swimming
larva

20. Cladogram of Modern Vertebrates

21. •Who is D’s closest relative?
•What do the blue lines represent?
•What do the green dots
represent?
C
Inherited characters
Nodes are common ancestors

22. Homework Assignment
•AZ Plant Mini-Poster due Thursday
•17.2 Main Ideas and Figures worksheet
due tomorrow.