1 Cell Biology TL Unit Contributors:

advertisement
Cell Biology TL Unit
Contributors:
Stephanie Aamodt, Beverly Clendening, Hans Landel, and John Rebers, Doug Luckie (facilitator)
Course Description:
Introduction to Cell and Molecular Biology. An introductory course for science majors (generalizable to
non-major courses; other courses in major). Enrollment of 50-200 students.
Concept
Unit covered is cell structure
Learning Goals/Objectives:
After completing this unit the student will:
• Describe cellular organization and the way this organization relates to function
o Describe the spatial and temporal organization of different types of cells
o Relate the organization of the cell to different functional activities
• Compare and contrast the organization of living and non-living objects
At the end of the course, the student will:
• Describe the hierarchal organization of living things, including the following levels:
o Chemical/molecular
o Cellular/organelle
o Tissue/organ/system
o Organisms/ecosystems
Rationale for Instructional Approach:
Student misconception: Students often think of the cell as a static, two-dimensional collection of
independent parts. Students memorize the names and definitions of the parts without understanding the
function or interrelationships of these parts.
The expert view of the cell recognizes that cells have dynamic spatial and temporal organization that is
important for function.
This lesson plan uses model-based reasoning and inquiry for students to develop skills and knowledge
they can apply later to understand the hierarchal organization of living things. The same approach could
be used for other systems, including physiology and ecosystems.
This unit will help students understand cellular organization. We begin by using organization of a familiar
machine, followed by the organization of the human body, to model the way that organization is required
for function. Students then use active learning processes to model the organization of cellular components
(molecules and organelles) and develop ideas about the way this organization is related to function.
FIRST National Meeting 2005
Kellogg Biological Station
Executive Summary
1
Brief Description of the TL Unit:
This TL Unit emphasizes scale and function to emphasize the dynamic nature of cell organelles
in one to two fifty minute classes. Students start by exploring the importance of the spatial and
temporal relationship among parts of a tree. The process is then repeated for a root and leaf cell.
To reinforce and assess understanding, students label a cell diagram with the functions of cell
organelles and build a concept map emphasizing the functional relationships between cell parts.
How Does the TL Unit Address Active Learning?
•
•
•
•
•
Group discussions relate parts of complex systems (car, human body) to the need for organization
(static and dynamic) to produce a functioning system
o For both car and human body:
 Students use think/pair/share to develop list of parts
 Informal groups are used to relate parts to function
 Class discussion relates organization of overall system to function
Students individually are responsible for developing list of cell parts
Informal groups are used to relate parts of cells to functions
Students use concept mapping to relate ideas of static and dynamic organization to show how cell
parts are organized and interact
“perturb and predict” activities stress critical thinking and allow assessment and reinforcement
FIRST National Meeting 2005
Kellogg Biological Station
Executive Summary
2
Cell Biology TL Unit
Brief Description of the TL Unit
Class Process:
1. What must a tree have to produce apples? Draw a model of an apple tree with all possible parts
labeled.
a. GROUP WORK: groups of 3 or 4
b. Draw a model of an apple tree labeling all possible parts. The model should
illustrate how the parts work together to help the tree produce apples.
The model should have
- Parts labeled
- Functions identified for each of the parts
- Arrows showing how resources ( water, CO2, sugar etc. ) are transported
2. Now use the model to help make an apple.
a. GROUP WORK (part 2):
b. Integrate all of the parts and processes of the model together into a logical sequence of
events to make an apple.
c. example: model illustrates water (and nutrient) acquisition by roots, transport of water
through trunk and stems to leaves, diffusion of CO2 into leaf, photosynthesis with CO2
and light in leaf, transport of sugar to flower and apple. The model can be more complex,
but this simple model will help them start to integrate processes
3. Assess understanding to this point: “perturb and predict” by having students develop scenarios
where 1) spatial and 2) temporal organization are perturbed effecting function.
a. GROUP WORK: groups of 3 or 4
b. You have an apple tree in your yard. Most years you have more apples than you
can eat. This year there was a drought and it appears that there are only a few
small apples on your tree. The some leaves have turned red and others have fallen
off the tree even though it is only mid August.
- Using your model, describe the processes and parts that might have
reduced apple production?
c. Selected groups present model as instructor builds class consensus model for apple tree.
4. FOCUS—Bring to cell level
a. GROUP WORK: groups of 3 or 4
b. Simultaneously repeat steps 1-3 for a leaf cell and a root cell. The two cells will help
identify differences in function and help connect from the cellular to the organismal
scale.
5. Mini-lecture on one cell organelle as illustration of how students should approach the material
a. Vote to decide which organelle to “uncover” first
b. re-emphasize organization concepts while doing this—connections, processes
FIRST National Meeting 2005
Kellogg Biological Station
Unit Description
1
6. Homework (critical thinking + assessment)
a. concept map – functional organization of cell parts
b. graphic – unlabeled cell diagram, label parts with functions, not names
c. Process – Using your concept map, predict what would happen if a particular
perturbation in a process occurs. Show where this perturbation occurs.
Grading Rubric – Cell Biology Concept Map
1. 5 pts
a. All assigned concepts listed included
b. Relationships between terms shown clearly using appropriate
connecting words
c. Network of relationships between ideas clearly shown
d. All significant relationships shown
2. 4 pts
a. All assigned terms included
b. Relationships between terms shown clearly using appropriate
connecting words
c. Not all important relationships between concepts indicated
3. 3 pts
a. All assigned terms included
b. Relationships between terms not shown clearly, or inappropriate
connecting words used
c. Network of relationships between ideas not shown clearly
4. 2 pts
a. Not all assigned terms included
b. Relationships between terms not shown clearly, or inappropriate
connecting words used
c. Network of relationships between ideas not shown clearly
FIRST National Meeting 2005
Kellogg Biological Station
Unit Description
2
Homework
A. Label all of the organelles and functions discussed in class on the figure below. Draw
additional lines as needed.
B. Quickly discuss why this is a leaf cell or a root cell? What organelles and
processes would differ between the two cells?
C. Use all of the organelles discussed in class to create a concept map illustrating the
functional relationship between the parts of a cell.
D. Using your concept map, predict what would happen if a particular perturbation in
a process occurs.
FIRST National Meeting 2005
Kellogg Biological Station
Unit Description
3
Eukaryotic Cell Organization:
Breaking the Jell-O Salad
Mold
Stephanie Aamodt, LSU-Shreveport
Beverly Clendening, Hofstra Univ.
Hans Landel, Edmonds Community College
Doug Luckie, MSU
John Rebers, Northern Michigan University
Description of the Challenge
  Our group: Cell/Developmental Biology
  Target: introductory biology course, majors or nonmajors, of any size
  The Misunderstanding: the eukaryotic cell is a collection
of individual and isolated parts, randomly arranged in the
cell
  The “Jell-O Salad” paradigm
  You will see later what we want students to think instead
the “Jell-O Salad” model (what our objectives are) because
we do not want to prejudice you, but we can tell you:
  Emphasis on model-based reasoning, relying on analogy
  Specific objectives are in our course description document
Learning Goals/Objectives
After completing this unit the student will:
•  Be able to describe cellular organization and the way this
organization relates to function
•  Be able to relate the organization of the cell to different
functional activities
•  Be able to make reasonable assumptions about the reasons for
differences between prokaryotic and eukaryotic cells
  At the end of the course, the student will:
•  Be able to apply the idea that function is dependent on
organized structure to the organization of living things,
including the following levels:
 
 
 
 
o
o
o
o
Chemical/molecular
Cellular/organelle
Tissue/organ/system
Organisms/ecosystems
Preliminaries
  Before this class
  Preliminary introduction to macromolecules
  Class discussion: Define “living things” and generate
list of requirements
  Introduce cells as the “smallest unit of life”
  All cells have membrane, DNA, cytoplasm
“The class part”
 Run through first part of class
Summary
  Car is organized
  parts
  subsystems
  systems
  connections
  Organization is important to function
  Car has processes
  simultaneous
  connections
  Processes important to function
  Processes and Organization are interdependent
“The FIRST part”
 Describe rest of class
TRANSITION: Bring the Class to
Biology
  have been examining a non-living object
  let’s use what we have learned about the car to
examine a living object -- the human body
TRANSITION: Bring the Class to
Biology
  The procedures with the car has served as a model for what
we would like the students to do.
  Car will serve as an analogy
  Now use the same procedure as with the car, but with the
human body
 
 
 
 
 
 
list functions body must perform to live
list body parts
categorize body parts according to function
parts must be assembled in correct locations
certain activities must occur for body to function
may or may not include formative assessment by performing
“perturb and predict” exercises
Concept Maps
  NOTE: Homework (assessment) will include
concept mapping of cell parts with respect to
function
  If students have not been introduced to concept
maps, a good place to introduce them is at the
point when they are asked to categorize the parts
of the body according to function. This will
model for them what we would like them to do in
the homework assignment.
Possible example concept map: plants
Example of a poor concept map
  “Sentence-in-a-box”
  Poor concept map
  Good concept map
should show complex
relationships
  One part can have
multiple relationships
  Use linking terms to
show how parts are
related
  Focus on most
important connections
FOCUS: Bring the class to
the cell level
  Important transition
  Have established a context for
describing and understanding the cell
Break the “Jell-O salad mold”
 More than a boring parts list
 Structures are not isolated; they are
interconnected
 Structures are not randomly placed; they are
highly organized
 The organization is not static; it is dynamic
Repeat steps 1 through 3
 Ask the class to list functions cell must
perform to live, and the parts of the cell
 Can the students group the parts according
to function?
 Can the students organize the parts of the
cell? Make connections?
Recognize that student
knowledge is limited
 Students will have some prior knowledge,
but it will be simple, pat definitions.
 Allow class to explicitly identify what they
don’t know or understand.
 Emphasize that what we don’t know as a
class will direct the rest of the unit.
Model a dynamic view of the cell
  Present an exciting mini-lecture on one cell
structure or organelle as an example for the class.
  Include a video clip of a cell process such as
mitosis or transport or a cell in motion.
  Describe how the structure is made of smaller
parts that fit together precisely to allow a specific,
controlled process
  (Here, “model” means showing students what we
expect them to do)
Encourage students to think
 The contextual framework will be
reinforced by homework and assessments.
 The dynamic, highly organized view of life
will be further developed in classes on
cellular respiration, mitosis and most other
topics, as well, as the course continues into
the study of cell biology.
Assignment
1.  Complete the structure/function chart for the cell
that was begun in class. The information can be
found in Chapter x of your textbook.
•  this forces the students to learn the parts on their
own, but within the context of function
2. Draw a concept map that shows the spatial and
functional relationships among
  nucleus
  endoplasmic reticulum
  ribosomes
  mitochondria
  cytosol
  synthesis of macromolecules (anabolic metabolism)
  breakdown of macromolecules for energy production
(catabolic metabolism)
Examples of connecting phrases (is connected to, takes
place in , etc.)
  this assesses their understanding of the concepts of
spatial and temporal organization
3. Label the cell compartments with their functions.
4. Predict, in detail, what would happen if
  Group A
•  there was a hole in the cell membrane.
•  the cell had no mitochondria.
•  a mature cell lost its nucleus.
  Group B
•  none of the ribosomes were attached to the endoplasmic
reticulum.
•  the process of vesicle formation could not occur (the Golgi
apparatus could not form vesicles).
  Pick one from Group A and one from Group B
  this assesses their understanding of the importance
of spatial and temporal organization of cells
The EXCITING significance of
this unit
  It covers a BIG idea in Biology
  It is “scalable” for use in other topics
The Big Idea
  Living Things Are Organized.
  Spatially- certain parts are located in certain
places
  Temporally - certain processes take place in
a certain order
  Function is dependent on both spatial and
temporal organization
  Interconnected
  Interactions
  Hierarchical (systems, subsystems, subsubsystems . . .)
Permeation of the “Big Idea”
  you can (and we think you should) re-examine the
importance of spatial and temporal organization
when the following cellular topics are discussed
  Metabolism
  Mitosis
  Protein synthesis
  Intracellular signaling
  Intercellular signaling
  our assessments can be used after any of these
topics, and in midterm and final exams
“Active Transport” of the “Big Idea”
  The Big Idea applies (by definition) to all levels of
biology. We think it should be continually
stressed.
• 
• 
• 
• 
• 
• 
• 
Macromolecules
Organelles
Tissues
Organs
Organisms
Communities
Ecosystems
Scalability of Exercise
 Because life is hierarchically organized,
with each level exhibiting spatial and
temporal organization (i.e., because it is a
Big Idea), this exercise can be used at any
level.
 (it has wide applicability)
Living things are organized.
  Replace “Living Things” with . . .
•  Macromolecules
•  Organelles
•  Tissues
•  Organs
•  Organisms
•  Communities
•  Ecosystems
Revisions?
 Feedback from FIRST participants suggests
  Transition (human body) step can be left out
  Car analogy has sexual bias -- women will
have a harder time relating to it
•  we had discussed this and had decided to address
this by calling on women first
•  also, you can use ANY object you would like as
your analogy, as long as it it sufficiently complex,
has processes, and is understandable by the
majority of your students (see course description
document)
Download