Longitudinal
Section
Cross
Section
Cross
Section
Monocot
Leaf with stomata (tip of pointer)
Leaf
with Stomata - Diocot
Roots
of a Dicot
Monocot
The
dark circles are vascular bundles scattered throughout the cross section of
the stem. Each vascular bundle consist of xylyem and phloem. Surrounding the
dark circles are transparent cells we call ground tissue (parenchyma cells).
Look
carefully at the tip of the pointer and you can see a structure that looks like
a mouth with lips. This is a stomata. It will open when the water pressure is
high and close when water pressure is low. These allows the plant to regulate
water loss and still exchange gasses (carbon dioxide and oxygen).
Check
out the stomata at the tip of the pointer. It is very small and not as visable
as the sample to the left.
In
this image the small little hairs coming off the root are called root hairs.
Active transport of nutrients in the root hairs causes the water to move into
the roots and eventually into the vascualar cylinder, root pressure.
The
root hairs are very visable in this image as well as the vascular cylinder (darker
line in the middle of the root)
Extra
Image: Very thin longitudinal section of dicot. Observe the cuticle and epidermis
with many stomata connecting the outside world to the inside of the leaf.
The
xylem and phloem can be seen arranged in a dark ring instead of scattered throughout
the stem. The ground tissue is located to the outside and inside of the vascular
ring. The center portion is void of cells and called the pith (most often found
in annuals)
If
you compare this longitudinal section to the monocot you see a distintive difference.
Here we have cut into the vascular tissue so all of the cells are xylem and
phloem cells. The epidermal cells can be seen on the edges (transparent.
Microscope Plant Lab
9th Biology Honors Lakeridge Junior High
Orem Utah
The purpose of this lab is to distinguish between monocots and
dicots and study the general anatomy of a plant. Plants are amazing creatures
that provide us with oxygen, food clothing etc. The two plants we observed
were corn (monocot) and bean (dicot). The images below are what you should
have seen through the microscope. You can finish the lab by looking at these
images. If you have questions let me know.
In this view you can see the vascular bundles from a different
angle. You can see the vascular bundles (xylem and phloem) as darker lines.
The lighter sections or lines is the ground tissue (parenchyma cells). The
xylem and phloem runs the entire length of the plant from roots to leaves.
