Fibrous Root System

Root system made by monocot plants; many thin, branching roots.

Tap Root System 

Root system found in eudicots; one thick main root

Adventitious Roots

Roots that form on above-ground plant parts such as stems or leaves.

Examples of tap roots

Carrots, dandelion, beet, parsnip

Examples of fibrous roots

Grass, onions, corn, wheat

Functions of roots

1. Absorb water and minerals
2. Anchor the plant in place, in the soil
3. Transport water and sugar
4. Store sugars and starch
5. If in the light, it can turn green and do photosynthesis

Epidermis

The first or outer cell layer of any root; it protects the root from damage and infection.

Cortex

The second layer of a root; parenchyma cells that can store sugars and starch.

Vascular Stele

Cylinder of tissue at the center of a root;

it contains the vascular tissue - xylem and phloem.

Endodermis

Layer of cells that outlines the vascular stele; 

controls the movement of water into the stele.

Casperian strip

Band of waterproofing that surrounds each cell of the endodermis; made of suberin

Pericycle

Layer of cells in the vascular stele; just inside the endodermis;

lateral roots form here.

Xlyem

in eudicot roots

Large cells at the very center of the root;

the cells are usually arranged in the shape of an X;

transports water

Xylem

in monocot roots

A ring of HUGE cells inside the vascular stele;

transports water

Phloem

in eudicot roots

Clusters of small cells arranged between the arms of xylem in the vascular stele;

transports sugars.

Phloem 

in monocot roots

Clusters of small cells arranged in a ring; near the large xlyem cells;

transports sugars

Pith

Parenchyma cells found at the very center of

monocot roots

Apoplastic Pathway of water

Non-living pathway through cell walls; from the root hair, along cortex cells, up to the endodermis.

This pathway ends at the Casperian strip of the endodermis

Symplastic Pathway of Water

Pathway of water through living tissue in root cells; it can begin at a root hair; water moves in the cytoplasm through plasmodesmata from cell to cell and around the Casparian strip into the xylem of the vascular stele