Stem Observation Lab

Objectives for this lab activity:

• Differentiate between monocot and dicot stems

• Be able to label and identify the various stem tissues

• Be able to name the functions of the various tissues

Materials:

• Microscope

• Prepared slides

• Colored pencils

Procedure:

Part A: Monocot Stems

• Obtain a prepared slide of a Typical Monocot Stem or Zea mays (corn)

• Sketch the specimen on low or medium power.

• Label the following structures:  epidermis, vascular bundle, pith, xylem, and phloem

Specimen:

Classification:

Magnification:

Part B: Dicot Stems

• Obtain a typical dicot stem slide.

• Sketch the slide under low or medium power.

• Label the following structures:  epidermis, cortex, vascular bundle, xylem, phloem, and vascular cambium

Specimen:

Classification:

Magnification:

Part C: Secondary Growth in a Stem

• Obtain the slide of Tilia. 2 year or 3 years.  Tilia is a tree that has secondary growth.

• Sketch the slide.

• Label the following:  primary xylem (oldest), 2nd year xylem, 3rd year xylem (if applicable)

• Where is the oldest xylem found in a dicot?  The youngest?

Specimen name:

Classification:

Magnification:

Part D:

After completing Parts A-C of the lab and returning your lab station back to the way it was originally, return to your seat and read “Tree Rings: Timekeepers of the Past”.  Answer the questions that follow.

1. What is “dating” with respect to trees?

2. How can trees relate to history or climate?           

3. What is “cross-dating”?

4. How is a sample taken from a living tree?

5. The science of dating events and variations in the environment be studying growth rings is called ______________________.

                                                                             LEAVES!

A microscope slide of corn I did last summer