Plants: The Inside Story

Plants: The Inside Story
Diagramming plant anatomy
Lesson
Plants, like all organisms, are made of cells. These cells are organized into
tissues. Tissues can be recognized by the size, shape, and arrangement of
the cells within them. While plants don’t have muscles, blood, or nerves
like animals, they do have different types of cells and tissues. Tissues, in
plants and animals, are organized into organs. Plants have three types of
organs: leaves, stems, and roots.
tissue – a group of very
similar cells that perform the
same functions.
Leaves: Up close and personal
In this lesson you will investigate the microscopic anatomy of a leaf and relate
its structure to its function.
1. What is the function of a leaf? What function does it perform for the whole
plant?
ì Open Lilac Leaf (320X).
This image is a photograph of a slide viewed under a microscope. The slide
was prepared by cutting a very thin slice across a leaf (see diagram in the
margin). The cells in the slice were then stained and put on a glass microscope
slide.
ì Make the structures in the image more clearly visible by sharpening
or adjusting the ¬ and Æ sliders in the Map window.
ì Carefully observe the structures in the image. Try to identify different
types of tissue. Each tissue will be made of cells of approximately the
same shape and size and may be in layers or other arrangements.
2. How many different tissue types can you see in this image?
 File/Open…
 Process/Sharpen or
Process/Enhance
Contrast
See the Look-Up Tables
IPTechnique Sheet for tips on
enhancing images.
Making a diagram of plant anatomy
Scientists often draw diagrams to make the relationships between microscopic
structures more evident. In the past this was done by hand from
microscopic images. In this part of the lesson, you will use image processing
to construct a diagram of the microscopic anatomy of a leaf directly from the
image.
To make a diagram directly from an image, we can use a special program
within NIH Image called Diagram Macro.
ì Load the diagram macro by choosing Load Macros… from the
Special menu. In the dialog box that appears, open Diagram Macro.
The macro adds new items at the bottom of the Special menu.
The macro creates a blank window where the computer will place your
diagram. This window is called the “Diagram Window.”
Check the Special menu to
make sure the macro has been
loaded.
ì Select Special/Create Diagram Window. A blank window (2/2)
will be stacked behind the image. Your diagram will be placed on this
window. Move back and forth between the two windows with the <
and > keys.
© 1996 Arizona Board of Regents. Limited classroom reproduction rights are granted under the notice appearing earlier in this work.
Plants: The Inside Story 105

ì Select a representative section of cells on the image to diagram. Use
the ¤ or › tool to draw a selection line around those cells, as shown
in the margin. Your boundary line will be as fat as the line selected by
the flÔ tool.
ì Mark the boundary of your selection on both the image and the
diagram window by choosing Outline Both? Yes/No in the Special
menu, and then choose Special/Outline. Check your boundary
on both windows.
ì If you don’t want your diagram to show on the image, choose Special/Outline
Both? Yes/No again and click OK.
Now you will outline the cells in your diagram with the six colors reserved at
the bottom of the LUT. Choose a different color for the cells in each tissue type.
ì To outline the cells in one tissue type with a color, use the following
steps:
(1) Activate the LUT by clicking the top of the LUT window. Choose
a color from the bottom of the LUT by placing your cursor on the
color you want to draw with (it will become a Ï) and click. The
color will show in the ‰.
(2) Use the fi tool to draw an outline around the edge of a cell in the
tissue you are diagramming. If you make a mistake, click outside
the selection and start over.
(3) Outline the cell on the diagram window by selecting Special/
Outline (or just type an “O”). View your diagrammed cell on the
diagram window by moving to slice 2/2 with the > key.
(4) Repeat steps 2 and 3 for each cell in the tissue you are diagramming.
ì Outline the cells of another tissue type using a different color. Continue
this process for each tissue type. When you have outlined all the
cells in your selection area, have another student or your teacher
review your work.
ì Use the Ë tool and Ç tool for labeling each of the following tissues
on your diagram: upper epidermis, lower epidermis, palisade layer,
spongy layer, air spaces, stomata, xylem and phloem.
3. Print your diagram of plant anatomy from the diagram window (slice
2/2). Attach it to your Data Sheet. If you don’t have access to a printer,
show your diagram to your teacher.
4. Using your diagram and your texbook, describe the structure and function
of each tissue in the leaf. How does the size, shape, and arrangement
of cells in each tissue relate to its function? Write your answers in the
table on your Data Sheet.
selection of cells in
leaf cross section
Tip: Use the ÿ tool to magnify
the cells to make outlining
easier. æ-click on the image
or double-click the ÿ tool to
reverse magnification.
See the Selecting
IPTechnique Sheet for tips on
making selections on an image.
See the Drawing & Text
IPTechnique Sheet for tips on
using drawing tools.
 File/Print (use draft mode
to save time). You may also
print the image for reference,
if time permits.
106 HIP BIOLOGY 1 © 1996 Arizona Board of Regents. Limited classroom reproduction rights are granted under the notice appearing earlier in this work.

Further Exploration
• Choose Name Groups… from the Special menu to name each of the
tissues in your diagram. Then choose Special/Sort & Show Results
to see measurements of area, perimeter, width, and height recorded for
each cell. Average the values to define the average size of cells in each
tissue.
• Diagram a stem or a root. Open the Roots or Stems folder located in
the Further Exploration folder. Choose an image to diagram using the
techniques described for the leaf. Compare and contrast the similarities
and differences between leaves, stems, and roots, or between monocots
and dicots.
selection of cells in
root cross section
stem
roots
• Look at the images in the Extra Color Images folder. These images
reveal the stains used to visualize the tissues under the light microscope.
What features of the cells do the stains reveal?
© 1996 Arizona Board of Regents. Limited classroom reproduction rights are granted under the notice appearing earlier in this work.
Plants: The Inside Story 107

108 HIP BIOLOGY 1 © 1996 Arizona Board of Regents. Limited classroom reproduction rights are granted under the notice appearing earlier in this work.

Plants: The Inside Story
Name(s)
Class
Date
Data
Sheet
1. What is the function of a leaf? What function does it perform for the whole plant?
2. How many different tissue types can you see in this image?
3. Print your diagram of plant anatomy from the diagram window (slice 2/2). Attach it to your Data Sheet. If
you don’t have access to a printer, show your diagram to your teacher.
4. Using your diagram and your texbook, describe the structure and function of each tissue in the leaf. How
does the size, shape, and arrangement of cells in each tissue help it perform its function? Write your answers
in the table below.
Tissue
Function
How does shape and arrangement
of cells contribute to function?
upper
epidermis
palisade layer
spongy layer
lower
epidermis
© 1996 Arizona Board of Regents. Limited classroom reproduction rights are granted under the notice appearing earlier in this work.
Plants: The Inside Story 109

110 HIP BIOLOGY 1 © 1996 Arizona Board of Regents. Limited classroom reproduction rights are granted under the notice appearing earlier in this work.