The Characteristics of Seed Bearing Plants

Leaves, Stems and Roots

Think about these questions

• Can a plant be as complex as the human body?

• Does every plant cell perform photosynthesis? If not, then how do those cells get food?

• Why is a tree trunk so strong?

VocabularyFor today’s

lesson

PalisadeEpidermisStomataXylem

Phloem

AngiospermGymnosperm

MonocotDicot

We’ll talk about these next time

Characteristics of Most Seed Plants

• Leaves• Stems• Roots• Vascular Tissue

Leaves

A leaf is composed of several layers

The upper epidermis is covered by a thin waxy protective layer called the Cuticle

Find a little space in your journal, you’re about to draw a picture

Don’t write that directly under your

drawing, you’ll need more

space.

Leaves

Below the epidermis is the palisade. The Palisade is densely packed with chlorophyll rich cells. These cells produce most of the food for the plant

The upper epidermis is covered by a thin waxy protective layer called the Cuticle

A leaf is composed of several layers

Leaves

Next is the spongy layer. Cells here are more loosely arranged. Veins containing vascular tissue, which carry water and nutrients to and from other parts of the plant, are found here.

Below the epidermis is the palisade. The Palisade is densely packed with chlorophyll rich cells. These cells produce most of the food for the plant

A leaf is composed of several layers

Leaves

Next is the spongy layer. Cells here are more loosely arranged. Veins containing vascular tissue, carrying nutrients to and from other parts of the plant are found here.

Finally, the lower epidermis contains the stoma. Stoma are holes in the epidermis that open and close with the help of guard cells. They allow CO2 in, which is required for photosynthesis, and let oxygen and water vapor out, of the leaf.

A leaf is composed of several layers

Stems

• Stems move materials between the roots and the leaves.

• Stems can be either– Herbaceous

• Soft and green like the stems of flowers

– Woody• Solid like the trunk of a tree

Please Read

• P. 254 & 255• Answer questions 5 and 6 on p. 262

Homework• Bring in a leaf on Tuesday. We will examine

them under the microscopes.• Write this and the Assessment Questions in

your Agendas NOW.

Yes, you will be turning this in.

But not yet, there’s one more question to add to

this page.

Roots• Grow down into the ground to:

– Support the plant– Pull necessary materials up into the plant

• Water• Nutrients• Oxygen

• Roots also store food– Carrots– Can you think of other roots which store food?

Vascular Tissue

• 2 types• Xylem and Phloem

Xylem

• Hollow tubular cells stacked to create vessels• Transport water and dissolved nutrients up

from the roots• Xylem helps give the stem strength and

support

Phloem

• Hollow tubular cells stacked to form tubes• Move food (sugar) from the leaves to other

parts of the plant to be used or stored

Please Read

• P. 256 & 257

How are Xylem and Phloem similar to the Arteries and Veins in your body?

– Read pgs. 550 and 556 to learn more about the functions of arteries and veins in your body.

Answer this question on the same page as

the other questions.