Download Basic Cell Structure

Basic Cell Structure
Name __________________
Lab Partner: __________________
Period _____ Date _________
Purpose: To observe and locate organelles within several types of cells.
Procedure:
Observe each cell type as directed below. For each type of cell perform the following and record your
results in the data table. Measure the length, width, and/or diameter of each cell. Record the presence
or absence of the listed organelles and structures that you observe. Draw, while on high power, a
detailed drawing of each cell you observe in the field of view circles provided for you. Label three of
the organelles that you observe.
A. Cheek cells. With a clean, flat toothpick, gently scrape the inside of your cheek. Rub the toothpick
on a clean, dry slide. Add a drop of Iodine stain and a coverslip. Examine the wet mount with low,
medium and then high power. CAUTION: If stain spillage occurs, rinse with water. Label the
cytoplasm, cell membrane and nucleus.
B. Amoeba. Use a prepared slide of Amoeba provided by your instructor. Normally Amoeba move,
but on prepared slides they are dead, therefor motionless. Examine the slide with low, medium and
then high power. Label the cytoplasm, cell membrane and nucleus.
C. Onion root. Place a prepared slide of a longitudinal section of an Allium root on the stage of your
microscope. Using low power, locate the meristematic and protective tissue. Meristem (reproductive)
cells are easily distinguished from other cells because their nuclei occupy nearly one-half of the cell
and are nearly square in shape. Some of these cells will have chromatin. In others, the chromatin has
condensed into rod-shaped bodies called chromosomes. Protective cells have shapes and contents
different from meristematic cells. Label the cell wall, chromosomes and chromatin.
D. Onion epidermis. Remove a scale from an onion that has already been cut into quarters. Peel the
thin, inner layer of the scale away using forceps or your fingernail. Place the tissue on a clean dry
slide. Add a drop of Iodine stain and a coverslip. Examine the wet mount with low, medium and
then high power. Label the cell wall, nuclear membrane and nucleus.
E. Elodea. Remove a young leaf near the growing tip of an Elodea sprig. Put the leaf on a slide and
add a drop of water. Add a coverslip to make a wet mount. Examine the wet mount with low,
medium and then high power. Observe the cells along the margin and those directly in the middle of
the leaf. Look for movement of chloroplasts within the cells. Label the cell wall, cell membrane and
chloroplasts.
F. Protococcus. With a probe, gently scrape some green scum from the Protococcus culture on a piece
of bark. The green scum is Protococcus. Place the Protococcus on a clean, dry slide and prepare a wet
mount. Observe the cells with low, medium and then high power. The individual cells are very small,
so make sure that you are not looking at a clump of cells. The chloroplasts are elongated green
bodies within the cytoplasm. Label the cell wall, chloroplasts and cytoplasm.
Data:
Structures (present P or absent A)
Cell Type
Cell Wall
Cell
Membrane
Nucleus
Cytopl.asm Chloroplasts
Motility
Others
Dimensions
(µm)
Cheek Cells
Amoeba
Onion Root
Elodea Leaf
Onion
Epidermis
Protococcus
Observations:
Basic Cell Structure
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Conclusion:
1.
Which cell is more complex, the Amoeba or cheek cells?
Why?
2.
What three structures do cheeck cells and Amoeba cells have in common?
3.
What two structures do Protococcus, Onion root, Elodea, and onion skin have in common?
4.
Which cells have chloroplasts?
What is the function of chloroplasts?
5.
Why was the nucleus not visible in Elodea cells?
6.
In which cells did you see movement of cytoplasm?
7.
What is the function of movement of cytoplasm?
8.
Which cells are unicellular organisms?
9.
Which cells are from multicellular organisms?
10. Are the cells we looked at in this lab eukaryotic or prokaryotic?
Basic Cell Structure
Explain.
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