Roots and Stems

Functions of Stems1.Support system for plant body

2.Transport system carries water & nutrients

3.Holds leaves & branches upright

Each light and dark tree ring equals one year of annual growth. Light rings for fast spring growth, dark for slow summer growth.

Smaller rings tell of past droughts that have occurred.

Looking at the picture to the left:

What years had the most rain?

What years experienced the worst drought?

Functions of Roots

• Absorb water and minerals from the soil root hairs

• Specialised cells to increase surface area for water intake

• Root hairs massively increase the surface area for absorption

Anchor & support plant in the ground

Fibrous RootsRoot Hairs

Wheat seed

Root hairs

Fragile parts of cells that grow from the main root

They massively increase the surface area for absorption

Root hair cells (x150)

Root ‘B’ has had the hairs damaged -

Root Types

2. Tap Roots –larger central root reaches deep water sources underground

Ex. Trees, Carrots, & Dandelions

1. Fibrous Roots: branching roots hold soil in place to prevent soil erosion

Ex. Grasses

Slide 3

Tap Root

1. Root Hairs: increase surface area for water & mineral absorption

2. Meristem: region where new cells are produced

3. Root Cap: protects tip of growing root

C. The Structure of a RootSlide 4

Root Hairs

Root Cap

Xylem

Phloem

Meristem