Biology Cladograms and Dichotomous Keys

Questions and Answers

What is a branching diagram (cladogram)?

A type of food chain

A representation of ocean currents

A method of measuring plant height

A branching, treelike diagram showing relationships between species (correct)

What does a dichotomous key do?

Lists specific traits of an organism to identify it.

What is a simple leaf?

An undivided leaf.

What defines a compound leaf?

A leaf consisting of several or many distinct parts (leaflets) joined to a single stem. Signup and view all the answers

What does bipinnately compound mean?

A compound leaf divided twice with leaflets attached to secondary rachises. Signup and view all the answers

What is opposite leaf arrangement?

Two leaves per node; directly across. Signup and view all the answers

What describes alternate leaf arrangement?

One leaf per node; alternating fashion. Signup and view all the answers

What is subopposite leaf arrangement?

Leaves and buds are not spaced sufficiently far apart. Signup and view all the answers

What characterizes whorled leaf arrangement?

Three or more leaves per node. Signup and view all the answers

What is pinnate venation?

Prominent midvein with secondary veins diverging from it. Signup and view all the answers

What is palmate venation?

Small veins branching from more than one main vein. Signup and view all the answers

What defines dichotomous venation?

Spreading vein pattern. Signup and view all the answers

What is parallel venation?

Vein arrangement in a leaf where the veins originate from the stem and remain nearly parallel to the tip. Signup and view all the answers

Study Notes

Branching Diagrams (Cladograms) and Dichotomous Keys

Branching diagrams, or cladograms, illustrate relationships among species based on evolutionary history from a common ancestor.
Dichotomous keys help identify organisms by listing specific traits, leading to precise identification.

Leaf Types

Simple leaf: Undivided structure, characterized by a singular leaf blade.
Compound leaf: Composed of multiple distinct parts known as leaflets, all connected to a single stem.
Bipinnately compound: A compound leaf that is divided twice, featuring leaflets attached to secondary rachises.

Leaf Arrangement

Opposite leaf arrangement: Two leaves emerge at each node, growing directly across from each other.
Alternate leaf arrangement: A single leaf at each node, positioned in an alternating pattern along the stem.
Subopposite leaf arrangement: Leaves and buds are closely spaced, lacking significant distance between them.
Whorled leaf arrangement: Characterized by three or more leaves emerging at a single node.

Venation Patterns

Pinnate venation: A prominent midvein with secondary veins branching out from it.
Palmate venation: Features smaller veins that originate from more than one main vein, creating a fan-like pattern.
Dichotomous venation: Displays a spreading pattern of veins throughout the leaf.
Parallel venation: Veins run nearly parallel from the stem to the leaf tip, maintaining consistent spacing.

Description

Explore the fascinating world of branching diagrams (cladograms) and dichotomous keys through these flashcards. Learn how these tools help in identifying organisms and understanding their evolutionary relationships. Perfect for students studying biology and classification.