ANGIOSPERMS:Monocot versus Dicots

ANGIOSPERMS:Monocot versus Dicots

Biology 112Biology 112

Monocots & Dicots• Botanists are able to divide the 235,000

species of angiosperms into two large groups based on the structure of their seeds

• Inside the seeds of angiosperms are tiny embryonic leaves called cotyledons. The seeds of one group of angiosperms have one cotyledon, called monocotyledons or monocots.

• Other angiosperms have two cotyledons. These are called dicotyledons or dicots

Cotyledon (seed leaf)Monocots versus Dicots

One cotyledon (seed leaf)

Two cotyledons (seed leaves)

The veins of The veins of monocot leaves monocot leaves are parallel to are parallel to each othereach otherThe leaves of The leaves of dicots usually dicots usually have netlike have netlike veinsveins

LeavesMonocot versus Dicots

Base of a Monocot Leaf: Note the Sheath which connects the Blade to the Stem

Typical Dicot Leaf with Reticulate (Net) Venation

Monocot Examples• Tulips, daffodils, irises, lilies,

palm trees• Do you see veins that are parallel?

Dicot Examples

• Buttercups, peas, roses, sunflowers, maple trees, and dandelions

• Do you see the netlike veins?

Which is which?

B is __________

A is _____________

StemsMonocot versus Dicot

Cross Section of a typical Dicot Stem

Cross Section of Corn which is a typical Monocot

Root SystemDicot versus Monocots

Dicot Monocot

Floral PartsMonocots versus Dicots

Monocots Dicots