Unit 7 Classification

Unit 7, Classification

(Unit DOCUMENTS are located at the BOTTOM of this page!!!)

Pictured above is Carolus Linnaeus (left) and the title page of the 1760 edition of Systema Naturae (right).

California Content Standards in this Unit:

7.3d Students will know how to construct a simple branching diagram to classify living groups of organisms by shared derived characteristics and how to expand the diagram to include fossil organisms.

Modern Classification Groups

Domain Is Currently The LARGEST (Most Inclusive) Classification Group

KINGDOM Is Currently The 2nd LARGEST (2nd Most Inclusive) Classification Group

Orcinus orca is in the Domain Eukaryota (Eukarya)

Constructing a Dichotomous Key with Shells

(This is the MAIN event for unit 7. See below for additional information.)

Cancellate (top), Concentric (middle), and Radial (bottom)

Shell Features (Traits)

REVIEW THE OTHER DESCRIPTIONS (TERMS) ON PAGE 2 OF THE LAB HANDOUT (UNIT 7 FOLDER)

10 HELPFUL HINTS FOR CONSTRUCTING A DICHOTOMOUS KEY

1. SEPARATE the SHELLS into GROUPS based on the TYPE of SCULPTURING (3!).

2. #1A & #1B on YOUR DICHOTOMOUS KEY tells the readers what number to go to for descriptions about the 3 groups of shells. You may ONLY HAVE (USE) 1 letter A & B for EVERY NUMBER ON YOUR DICHOTOMOUS KEY. With 3 total groups, #1A should direct the readers to #3 for the smallest group, and #1B should direct the readers to #2 for the OTHER 2 GROUPS (2nd largest & largest).

3. #2A should direct the readers where to go for the 2nd largest group (NUMBER TO BE FILLED IN AFTER ALL OF THE SMALLEST GROUP HAVE BEEN DESCRIBED) and #2B should direct the readers where to go for the largest group (NUMBER TO BE FILLED IN AFTER ALL OF THE 2nd LARGEST GROUP HAVE BEEN DESCRIBED).

4. #3A should describe the SMALLEST shell in the SMALLEST (fewest) GROUP. #3B should direct the readers to the next number IF THERE ARE 2 OR MORE SHELLS LEFT. IF THERE IS ONLY 1 SHELL LEFT, describe the last shell in #3B.

5. #4A would continue describing shells from the smallest group and #4B should direct the readers to the next number IF THERE ARE 2 OR MORE SHELLS LEFT. IF THERE IS ONLY 1 SHELL LEFT, describe the last shell in #4B.

6. After you have FINISHED DESCRIBING THE SMALLEST GROUP, the NEXT NUMBER ON YOUR DICHOTOMOUS KEY SHOULD BEGIN DESCRIBING THE 2nd LARGEST GROUP (letter A) and letter B should direct the readers to the next number IF THERE ARE 2 OR MORE SHELLS LEFT. IF THERE IS ONLY 1 SHELL LEFT, describe the last shell in letter B.

7. Continue describing shells in the group from SMALLEST to LARGEST until all shells in the 2nd largest group have been described.

8. The NEXT NUMBER (after 2nd largest group have all been described) begins descriptions of the LARGEST (MOST PLENTIFUL) GROUP. Letter A should describe the SMALLEST shell in the LARGEST (most plentiful) GROUP. Letter B should direct the readers to the next number IF THERE ARE 2 OR MORE SHELLS LEFT. IF THERE IS ONLY 1 SHELL LEFT, describe the last shell in letter B.

9. Continue describing shells in the group from SMALLEST to LARGEST until all shells in the largest group have been described.

10. HAVE FUN!!

The Shells:

Above: This shows how your shells must be returned at the end of every class.