Moore, Timothy
Moore, Timothy
Instructor: Mrs. Tammy Moore
Class: VHSG Online Biology
29 November 2010
EXPERIMENT 14.3
Cross Sections of roots, Stems, and a Leaf
Observing the microscopic structure of a leaf and comparing the microscopic structures of monocot and
dicot stems and roots
Abstract
[What you will put here: Summarize the whole report in one, concise paragraph of about 100-200
words. You cannot write the abstract until after you've completed the report. Because it assumes that
you will speak to your conclusion or what you learned in brief.]
Introduction
[What you will put here: In this introduction, some background is provided for the reader
(sources are noted in the reference section at the end of the report).Typically, the introduction states the
problem to be solved or the experiment to be performed and explains its purpose and significance. It
also provides whatever background theory, previous research, or formulas the reader needs to
understand to perform the experiment (or solve the problem).]
Methods and Observations
Materials
 Prepared slide: Zea mays (corn) cross section of stem
 Prepared slide: Zea mays (corn) cross section of root
 Prepared slide: Ranunculus (buttercup) cross section of stem
 Prepared slide: Ranunculus (buttercup) cross section of root
 Prepared slide: Leaf cross section with vein
 Microscope
Moore, Timothy
 Lab notebook
 Colored pencils
Procedure:
A. Observation of a leaf cross section
Using my microscope and prepared slide set, I observed the prepared slide of a leaf cross
section. I began with the lowest magnification, and as I became familiar with the slide, I
increased the magnification until I found the optimum magnification for viewing the slide.
[100x is usually the best.] I used the Figure 14.7 in my Apologia Biology text to guide me
through the various structures, including the upper epidermal cells, palisade mesophyll, veins,
spongy mesophyll, lower epidermal cells, guard cells, and stomata. [Although your leaf cross
section might not look exactly like Figure 14.7, you should be able to use it as a guide to find
the structures.] I concluded this section of the lab by drawing the cross section and labeling all
of the structures that I was able to identify.
B. Observation of a lateral cross section of a Ranunculus root
Continuing, I observed the prepared slide of the Ranunculus (a dicot) root cross section. Again,
I began with the lowest magnification. Upon viewing the slide, I drew what I observed, and
identified the epidermis and cortex. [Figure 14.11 in the text can be used as a guide in helping
you identify the structures.]
I then centered on the vascular chamber and increased the magnification. I again drew what I
observed, and using Figure 14.11 in the text as a guide, I was able to identify the xylem,
phloem, pericycle, and endodermis.
C. Observation of a lateral cross section of a Zea mays root
Zea mays is the binomial name of corn, which is a monocot. Using the prepared slide in my
microscope kit, I observed the Zea mays root under the microscope on the low magnification.
Moore, Timothy
After observing the slide, I made a drawing of what I saw, and labeled the epidermis, cortex,
and endodermis. [Though the text did not show you a figure of the root of a monocot, you
should still be able to identify the structures. If you need assistance, you can visit the course
website that was mentioned in the “Study Notes” section of your text; there are some links to
pictures that will help you.] I then centered on the vascular tissue, which is just on the inside of
the endodermis. I increased magnification to see if I was able to distinguish the xylem from the
phloem. [Were you successful in doing this?]
A monocot root has a section of pith. [State whether you were able to identify the pith in your
specimen.]
After viewing both a dicot and monocot root, I was able to note the differences between the
two. [What are the differences between the two?]
D. Observation of a lateral cross section of a Zea mays stem
I next viewed the Zea mays stem on low magnification, and made a drawing of my
observations. I used Figure 14.12 in my text as a guide in identifying and labeling the
epidermis, cortex, and fibrovascular bundle. I then centered on one of the fibrovascular bundles
and increased the magnification setting to high. I again made a drawing of what I observed and
used Figure 14.12 in the text to identify and label the xylem, phloem, and air space.
E. Observations of a lateral cross section of a Ranunculus stem
The final slide I viewed was the Ranunculus stem. I viewed this on the lowest magnification
and drew what I observed. Using Figure 14.12 as a guide, I identified and labeled the xylem,
phloem, and vascular cambium.
After studying both a monocot and dicot stem, I noted the differences between the two. [What
differences were you able to find?]
Moore, Timothy
Clean Up:
When I was finished viewing the slides and noting my observations, I returned the prepared
slides to their case and put my microscope away.
DATA:
[Include your lab notebook sketches and photographic images here.]
Conclusion
My observations [You must explain, analyze, and interpret your results, being especially careful
to explain any errors or problems.]
References
Dr. Jay L Wile and Marilyn F. Durnell
Apologia Exploring Creation with Biology, 2nd edition, copyright 2005 Apologia Educational
Ministries, Inc