Life Science



Name ________________________________________ Date ________

Activity: Observing Vascular Tissue

Goals:

1. To observe the structure of vascular tissue in

plant stems, roots, and leaves.

2. To determine the function of phloem and xylem

tubes in vascular plants.

Background Information: Vascular plants first appear in

the fossil record about 410 million years ago.

Vascular plants are plants with tube-like cells that make up

vascular tissue. The tubes are constructed of lines of

interconnecting cells. These tubes serve as a means of

transport for food, minerals, water, and other materials within

the more advanced plants.

This method of transport is a much more sophisticated system

than the cell-to-cell system used by more primitive plants like

mosses and liverworts. (These more primitive plants are called non-vascular.)

Because of the development of vascular tissue, vascular plants can grow very large.

Phloem and xylem cells are the two main components of vascular tissue. (Other components are fiber cells for strength and storage cells for storage.) Phloem tubes transport food that is made by the leaf during photosynthesis. The food is brought from the leaf down to all other parts of the plant. Xylem tubes transport water and minerals from the roots up to the stem and the leaves.

Materials: Prepared slides of vascular tissue: roots, stems, and leaves, food coloring, beaker of water, celery stalks, scalpels, hand lenses,

Procedure:

Complete the following stations. Be sure to answer all questions using complete statements.

Station 1: Transporting Materials Demonstration

The celery stalks at this station were placed in a vase filled red food coloring.

a. Observe the celery stalks and draw what you observed.

b. Answer the following questions:

a. What do you notice about the leaves at the top of the celery stalks?

b. How did the coloring reach the top of the stalks?

Station 2: Vascular Tissue Slide

Hyperlink: Vascular Tissue Images

1. Observe the prepared slide of vascular tissue under the microscope. There are two different types of tissue on the same slide, a monocot stem and a dicot stem cross section. Select only one type to draw. Experiment with the magnification until you find your best view.

2. Review pages 131 and 141 in your text book and answer the following questions:

a. What is vascular tissue?

b. What is xylem?

c. What is phloem?

d. Why is vascular tissue important to plants?

3. Draw and label the vascular bundles in your drawing. Vascular bundles include xylem and phloem.

[pic]

Station 3: Vascular Bundles

A. Lateral View (Horizontal View)

1. Cut off a small, lateral/horizontal cross section of the celery stem.

2. Using a hand lens observe the small vascular “bundles.” They were stained red by the food coloring.

3. Draw and label a vascular bundle.

Drawing/Label

B. Vertical View

1. Peel off a vertical slice from the outside of your celery. Find the red-dyed tube-

like cells. Very carefully peel off one of the tubes. This is vascular tissue.

2. Draw and label the vascular bundle in this view.

Drawing/Label

Complete this lab activity by responding to the following prompts. Be sure to answer in detail by providing examples from the activity.

1. What I Observed:

2. What I Learned:

3. What I Wonder:

-----------------------

Rhynia, the first known plant

with a complete fossil.

_____X

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download