Root Zones and Tropisms

Root functions

•Anchors the plant•Absorbs water and minerals•Sends water and minerals

to the xylem

Parts of a root

Xylem carries water,Phloem carries food

Parts of a root

Root hairs- absorb water and minerals

Parts of a root

Area of Mitosis:growth

Parts of a root

Root Cap:Digs into ground

2 basic types of roots•1. Fibrous•Roots are tangled

together•Helps prevent

erosion

•2. TAPROOT•one long root, like

dandelion

What is it?• Spanish

moss

Root adaptations• A change that helps

an organism survive• 1. Aerial Roots• Grow above ground,

up in the air, suspended in a tree

• Usually in rain forest, can get water from air and rain

• Examples: Spanish moss, orchids

Aerial roots

Orchid

More Spanish moss

Why?• Tree canopy is 100-200 ft in air• Jungle floor is very dark

So an aerial root

• Can grow 150 ft up in the air• Without having to put down roots

into the soil• Can grow where the sunlight is

without competition from the trees

What is unique about this plant?

PROP roots

• Above ground roots, but most of root is underground

• Used to support a top heavy plant• Examples are corn and• Get ready, this is really really cool• Banyan tree• Ready?

All one treeroots grow out of branches to

support the weight

TROPISMS

• Response to a stimulus• Controlled by chemical hormones

called auxins

Hydrotropism

• Response to

•Water• Sketch:

Phototropism

• Response to

•Light• Sketch:

Geotropism or gravitotropism

• Response to

•Gravity