Parts of a Vascular Plant

Objectives: •Explain the main functions of the vegetative parts of a plant•Notes = yellow

Parts of a plant

• The tissues in a plant can be divided into two main groups:

• Vegetative: Roots, Stems and Leaves

• Reproductive: Seeds (+ fruits and flowers in angiosperms)

Roots

Function: Anchor a plant to the ground Absorb water and minerals from the soil Sometimes store food

Types of Roots

There are two main types of roots: Fibrous: Consists of many similarly sized roots

that form a dense tangled mass.

What happens when you try to pull a fibrous root out of the soil?

Taproots: Consists of one long thick main root, with many smaller roots that branch off the main root. Taproots are often used to store food.

Structure of a Root What is the purpose of

the root cap? What is the purpose of

the root hairs? Would you expect to

find chloroplasts in roots? Why?

Stems

Function: Produces branches, leaves and flowers. Carries substances between the plant’s roots and

leaves. Provides support for the plant and holds up leaves

so that they are exposed to the sun.

Stem Structure

Stems consist of vascular tissue as well as many other supporting cells.

The vascular tissue in a plant consists of Xylem: flows up from root to leaves. Xylem sap

consists of water and inorganic ions. The word xylem is derived from the Greek word for wood.

Phloem: flows down from leaves to roots. Phloem carries the product of photosynthesis (sucrose) to the parts of the plant that need it. The word phloem is derived from the Greek word for bark.

Types of Stems

Herbaceous Stems: Stems with no wood. Often soft. The vascular tissue is arranged in a ring. Usually contain chlorophyll.

Woody StemsTissue is arranged in layers. Outer bark: protects the

cells Inner bark: Living

phloem Cambium: Produces

new xylem and phloem Sapwood: Active xylem Heartwood: Old

inactive xylem.

Questions to ponder

Based on the picture and what you just learned from woody stems, Which part of the stem is tapped by maple syrup

producers? What happens to a tree trunk as it “grows”? Where is the oldest part of a tree?

Leaves

Leaves come in all shapes and sizes. However, the structure of leaves is adapted for capturing the sun’s energy and carrying out photosynthesis.

Leaf structure

Cuticle: waxy waterproof coating that controls water loss.

Upper leaf cells: tightly packed, trap sunlight.

Lower leaf cells: widely spaced allow carbon dioxide to reach cells and oxygen to escape

Stomata: Pores on the underside of the leaf that open and close to allow gases to enter and exit the leaf.

Now for applying concepts

With your table draw a three way Venn Diagram to compare/contrast the function and structure of leaves, stems and roots.