Compare the functions of roots, stems, and leaves

S7-3-1

Roots

Roots—3 main functions

1. Soak up water from ground

2. Anchor plant to ground

3. Store food

Roots—2 main typesFibrous root Branching root system Spreads out

underground Ex. Corn, trees, many

weedsTap root One large root Does not spread out

but may grow deep Ex. Dandelions,

carrots, radish

Parts of a Root Root hairs

Increase surface area Bring in more water

Cortex Stores food

Vascular cylinder Central “core” Contains growth tissue,

phloem, xylem Root cap

Protects root tip as it grows through the soil

Specialized Roots Prop Roots—above

ground, give support Ex. rainforest tree,

corn

Pneumatophores—roots extensions reach above water to get oxygen

Ex. mangrove

More Specialized Roots

Buttress Roots—thick roots (extensions of trunk) that give support

Adventitious Roots—roots that can sprout from other tissues; may grow a new plant forma clipping

Ex. ivy, philodendron

Even More Specialized Roots Contractile roots— pull a plant

into the soil to the correct depth Ex. onion, tulip bulb

Haustorial root—parasitic roots that dig into another living plant’s roots to steal water and food

Ex. misteltoe

Not done! Specialized Roots III

And the final & biggest specialized use of plant roots . . .

FOOD STORAGE! All plants store food in their roots, but these plants go overboard!

Water storage—store water underground

Ex. Cucurbita foetidissima—may store 158 lbs of water!

Specialized Roots—Food storage

Turnip

Sweet potato

CassavaRutabaga

Radish

Beet

Carrot

Answer each question below on a separate sheet of paper.

1. What are the 3 functions of a root?2. What are the 2 main types of roots?3. What tissue would you find inside the vascular

cylinder?4. Why does a plant have root hairs?5. What may happen if a root doesn’t have a root

cap?6. Where is food stored in the root?7. Name 3 examples of specialized roots.