Grade 8 Science
Life Science 8.3: Cells, Tissues, Organs, and Systems
Mackenzie Kleiboer
Lesson #21- Classical Cell Theory
Engage: (5-7 minutes) Video on a timeline (to strike interest I thought showing the
Evolution of the Cell Phone) to get students thinking about what a time line is. Discuss
what a timeline is then explain we will be making on cell theory.
Explore: (25-30 minutes) In pairs have students research various scientists and their
contributions to cell theory. See Chart
Construct a timeline of the events. See Timeline Assignment Sheet
Explain: (13-20 minutes) Answer questions using timeline. See Questions Sheet
Evaluation: Discuss questions and mark as a class. Timeline teacher assessed, See
rubric.
Materials:
Computers for each student
Paper
Rulers
Writing utensils
Research Chart- Contributors to Cell Theory
Name: ______________________________________________________
Date: _______________________________________________________
You and your partner must complete the chart using information found during your
research. You will be asked to research each scientist, state their contributions to cell
theory and the year they are credited with their discoveries.
Scientist
Robert Hooke
Hans and Zacharias
Janssen
Anton von Leeuwenhoek
Year of Discovery Contribution to Cell Theory
Louis Pasteur
Matthias Schleiden
Teodor Schwann
Rudolf Virchow
Timeline Activity
Once you have completed your research you and your partner will construct a timeline
that chronicles the events of classical cell theory.
Include the Following in your Timeline:
1. Labels with dates of the above scientists' discoveries. (The earliest date should
be on the left of the timeline and the most recent date on the right.)
2. Labels of each date with the corresponding scientist's name and contribution(s)
in an organized and legible manner.
3. Be sure your spacing shows a reasonable approximation of the amount of time
elapsed between dates.
4
3
2
1
Content/Facts
Facts were accurate
for all events
reported on the
timeline.
Facts were accurate
for almost all events
reported on the
timeline.
Facts were accurate
for most (~75%) of
the events reported
on the timeline.
Facts were often
inaccurate for events
reported on the
timeline.
Dates
An accurate,
complete date has
been included for
each event.
An accurate,
complete date has
been included for
almost every event.
An accurate date
has been included
for almost every
event.
Dates are inaccurate
and/or missing for
several events.
Learning of
Content
The student can
accurately describe
75% (or more) of the
events on the
timeline without
refering to it and can
quickly determine
which of two events
occurred first.
The student can
accurately describe
50% of the events
on the timeline
without refering to it
and can quickly
determine which of
two events occurred
first.
The student can
describe any event
on the timeline if
allowed to refer to it
and can determine
which of two events
occurred first.
The student cannot
use the timeline
effectively to
describe events nor
to compare events.
Preparation
The student had
notes about all the
events and dates
s/he wished to
include on the
timeline before
beginning to design
the timeline.
The student had
notes about almost
all the events and
dates s/he wished to
include on the
timeline before
beginning to design
the timeline.
The student had
notes about most
(~75%) of the events
and dates s/he
wished to include on
the timeline before
beginning to design
the timeline.
The student had not
prepared adequate
notes before
beginning to design
the timeline.
CATEGORY
Total-
/16 marks
Cell Theory Questions
Name: ______________________________________
Date: _______________________________________
Once you have completed your timeline please answer the following questions, in
complete sentences, and hand in for exit work.
1. What theory did these scientists provide evidence for?
2. What instrument was necessary before the cell theory could be developed?
3. Which 3 scientists directly contributed evidence for cell theory?
4. How did the earlier scientists and their contributions directly affect the discoveries
of later scientists? For example, what had to come first?
5. List the three parts of cell theory.
Teacher notes:
Sample Timeline
Answers for Questions
1. What theory did these scientists provide evidence for?
*the cell theory
2. What instrument was necessary before the cell theory could be developed?
*The microscope
3. Which three scientists directly contributed evidence for the cell theory?
*Matthias Schleiden, Theodor Schwann, Rudolph Virchow
4. How did the earlier scientists and their contributions directly affect the discoveries of
later scientists (see #2)? For example, what had to come first?
*Hans and Zacharias Janssen had to first develop the microscope before cells could be
discovered. Robert Hooke then discovered empty, dead cork cells in tree bark. Anton
van Leeuwenhoek discovered the existence of living cells and is sometimes given credit
for the microscope.
5. List the three parts of the cell theory.
*All living things are made of cells.
*Cells are the basic units of structure and function in living things.
*Living cells come only from other living cells