Download Poor Primitive Prokaryotes

Name_____________________________________ Date_____________ Period_______
Poor Primitive Prokaryotes
Purpose: To identify and define similarities and differences between prokaryotic and
eukaryotic cells
Background: Cells are the basic units of life. New and better instruments, such as electron
microscopes, have allowed scientists to study the structure of living cells in increasing detail.
In doing so, it was discovered that there are two basic kinds of cells: prokaryotic and
eukaryotic.
Prokaryotic cells do not have a nucleus or any internal membrane-bound structures. Within
these cells, membranes do not separate different areas from one another. Bacteria in the
Kingdom Monera are prokaryotes. There are some universal structures that all bacteria
have. Like every living organism, they have the basic building blocks of life -- DNA, RNA, and
protein. Therefore, these prokaryote cells will generally have an area of genetic material but
no nuclear membrane. They will also have RNA and free-floating ribosomes for protein
synthesis. In addition, all bacteria have a cell membrane, and most have a cell wall outside
that. Since prokaryotic means “without or before nucleus,” it may help to remember them
as the POOR, PRIMITIVE PROKARYOTES. (Pro means before and karyote means nucleus.)
In contrast, eukaryotic cells have many kinds of internal membrane-bound structures called
organelles. Essentially then, eukaryotes have EVOLVED EVERYTHING IN ENVELOPES. The
most important of these is the nucleus where the hereditary DNA is separated. Compared
to prokaryotes, eukaryotes are much more compartmentalized and specialized. Eukaryotic
cells are present in all living things except bacteria that would include protists, fungus, plant,
and animal cells. (eu means true and karyote means nucleus.)
The following activity will provide practice in recognizing the similarities and differences
between prokaryotes and eukaryotes.
Materials/Equipment:
Index cards
Poster paper
Safety Considerations: Always follow lab safety procedures.
Pre-Activity:
1. Divide the cell structures listed on the observation Data Table among the group
members. Use descriptions and diagrams from the text to write a brief summary on
an index card to describe the nature of that cell part.
Activity:
1. When all cards have been prepared, shuffle them and place the stack face down in
the center of the circle.
2. Take turns having a group member draw a card from the center, read its description
aloud, and place it into one of the three pie segments. If the cell part would only be
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3.
2.
3.
4.
found in prokaryote cells, the card should be placed in the “P” segment. If the cell
part would be found in eukaryote but not in prokaryote, then the “E” segment
should be chosen. However, if the cell part would be common to all cells, the card
should be placed in the “B” segment for both.
Once the card has been played, the group has the opportunity to agree or disagree
with the decision. Another group member may move the card but must justify the
new placement.
Play resumes in a counter-clockwise fashion until all cards have been placed.
Ask the teacher to review the cell pie. If all of the selections were correct, mark
them on the Data Table.
If cards have been incorrectly placed, the teacher will reveal only the number in
each segment that should be reevaluated. The group may discuss these, make new
placements, and ask for another review until all are accurately arranged. Post these
corrected selections in the Data Table.
Post-Activity:
1. Using the table and samples from the text, draw and label the components of a
typical prokaryotic cell and of an animal eukaryotic cell. (Note: Don’t forget the “B”
items in the sketches.)
Data Table:
P
CELL TYPE
E
CELL STRUCTURES
B
Cell Wall
Cell Membrane
DNA
Nuclear Membrane
Cytoplasm
Vacuoles
Endoplasmic Reticulum
Golgi Bodies
Mitochondria
Ribosomes
Lysosomes
Nucleolus
Sketch of Prokaryote cell (bacteria)
Sketch of Eukaryote cell (animal)