TOOLS OF THE BIOLOGIST

Biology

ToolsDichotomous Key

Di- Two Chotomous- Forks or Branches Used to identify…… Region Specific

Deciduous Tree Key Deciduous- to shed all leafs on an annual basis/

usually a broad leaf tree. Bark vs. Leaf Characteristics

Deciduous Tree Key

Fall Leaf Color?

Deciduous Tree Key

Basic Leaf Anatomy

Basic Leaf Anatomy Blade- Green or colored region of the leaf.

Extends from the tip to the base. Tip- Top of the Blade Base- Bottom of the Blade Mid Rib / Main Vein- all mid ribs are main veins

but not vice versa. Margin- Edge of Blade Petiole- Stalk that may or may not be present. Stipule- Bud that marks the point of attachment of

a single leaf to the stem. ***When counting leafs, count stipules not blades.

Main Vein / Mid Rib

Main vein- any dark thick easily seen vein.

Mid rib- a main vein that divides the blade in half

Leaf Characteristics1. Leaf Arrangement- How the leafs are arranged on

the stem. Alternate- Not opposite Opposite- across from each other.

○ M- Maples○ A- Ashes○ D- Dog Wood

○ Horse- Horse Chestnut

2. Leaf Type- how many blades per stipule. Simple- one blade per stipule Compound- more than one blade per stipule

HW Draw a branch showing four alternatively arranged

simple leafs.

3. Types of Compounding Palmate- “Fingers extending from your palm.” Pinnate- not palmate

○ Leaflet- Blade on a compound leaf○ Note- Terminal Leaflet ○ Note- Lateral Leaflet

4. Venation- Vein Arrangement Palmate Pinnate

5. Lobbing Lobe- section of the blade created by deep

indentations in the margin.

Palmate Pinnate

Maple Leaf Oak Leaf

Palmate Vein=

Palmate Lobed

6. Margin Type Entire- Smooth Toothed

○ Finely○ Coarsely○ Compound

See Drawing

7. Blade Attachment Non-Sessile (Stalked)

○ Contain a petiole

Sessile○ Contain no petiole

See Diagrams

8. Lopsided leafs / Notched leafs and Leaflets Lopsided Leafs- associated with simple leafs

Notched Leafs and leaflets○ Associated with complex leafs.