Download Sample Concept Building Lesson Plan

Jessica Thompson
11/16/04
EDTEP 586
“Using the model of a Punnett Square to predict offspring ratios”
7th/8th grade life science
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Objectives:
Objective 1: Students will know that chromosomes have genes that control the phenotype
(appearance) of organisms
Objective 2: Students will calculate the percentages of various types of potential offspring
based on a simple dominance model and using a single trait.
Objective 3. Students will extend the model of the Punnett Square in order to apply the
concept of simple dominance to new traits.
Resources:
PowerPoint
Handouts of empty Punnett Squares
Tasks for the day handout
Post-Its
7 beakers
Pieces of paper for beaker baby activity
References:
http://fig.cox.miami.edu/~cmallery/150/mendel/heredity.htm
Do before class:
 Write on board, “Will your kids be able to roll their tongue?” also leave a section
for “Our questions”
 Set out beakers and tiny pieces of paper.
Safety considerations: None necessary (If there are safety precautions, write on board
before class).
Opening:
(1 min)
Instructional
flow:
(5-7 min)
We have been talking about the idea of sperm and egg getting together to
create a new life. We know that this happens in both plants and animals. In
animals, the male contributes the sperm, and the female contributes the egg.
In plants, the male part of the plant contributes pollen, which acts like the
sperm, and in the female part of the plant is the egg.
Yesterday we talked about how we look like our mothers or our fathers, but
we didn’t take the conversation very far.
Pose ProblemWill your kids be able to roll their tongues?
Connecting to students & focusing on concept they can relate to through
questions- There are some mysteries involved in how you all have inherited
traits from your fathers and mothers.
• If we look at brothers or sisters who all come from the same parents,
do these brothers and sisters all look exactly the same? So are we not clones
of our parents?
• What are some differences between brothers or sisters who come
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from the same parents?
Another question:
• If you have a mother who is 5 feet 5 inches tall and a father who is 6
feet tall, and they have four children, how tall do you think they should be?
All the same?
• Is it possible for a child to end up shorter than both parents? Or taller
than both parents?
One more question, have any of you seen a person who looks like they have
the traits of one of their grandparents but not the parent, like the traits skipped
a generation? Do any of you have traits more similar to your grandmothers or
grandfathers than your parents?
Just in time instruction, teacher adds a little information- To begin to
understand how these kinds of traits can be inherited, we have to go back to
the idea of the sperm and the egg contributing to who we are.
We have mentioned that in order to create a human being, you need sperm
from a father and an egg from the mother (show the 46 chromosomes). These
paired chromosomes are made up of thousands of sections called genes. Each
gene controls some kind of trait, like color of hair, or color of eyes, or
contribute to height. There are about 100,000 genes that make up the human
body.
We have talked about the 23 chromosomes that are in each sperm cell and the
23 chromosomes that are in each egg cell. These chromosomes look
something like this (show chromosomes).
So, when humans are first formed from one sperm and one egg cell, we get
two of each of the 23 chromosomes, and, with those 23 chromosomes from
each parent comes all the genes on each chromosome. So you have one gene
for eye color from your father and one from your mother. You have one gene
for the shape of your earlobes from your mother and one from your father.
You have two of each.
Stop for questions— (Make a list of student questions that can’t be answered
right now but that will guide later discussions on the blackboard)
Involving students in analogy building- What is interesting is that we can
tell a little about what kind of genes we have by observing various traits in
ourselves. I’d like you to take a little data now with your classmates (show
earlobes and tongue). There is a gene for whether or not your earlobes are
attached and a gene for whether you can roll your tongue. I’d like you in pairs,
to record the number of people that have attached versus free earlobes. Then
do another chart for the tongue.
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Elicit student ideas and build an analogy for dominance- There seems to
be a larger number of people who can roll their tongue. Let’s see if we can
determine why and see if we can answer the essential question for the day.
How would you explain this difference?
WAIT for student responses & descriptions
Then introduce dominance/recessiveness (mesh science definition with
student definition)- The reason is because the gene for the ability to roll your
tongue or to have free earlobes is called dominant. The genes that tell your
body to have attached earlobes, or that do not let you roll your tongue are
recessive. Here is how it works:
Activity to apply new knowledge- (TEP Colleagues- you will probably
not have time to include this in your microteaching)
Beaker Baby Activity
Explain Punnett Squares: YOU FILL IN AS I GO! STEP 1, 2, 3, 4,
F (free) f (attached)
F (free) f (attached)
These are the combinations that are possible. Only possible! They are all
equally possible.
We said that free earlobes were dominant, that means kids with just one will
show it. So which of these combinations of kinds will show free earlobes? Go
through each cell, what will they look like?
Hand out two empty Punnett Squares each & beakers & pieces of paper.
The only way to have attached earlobes is to have two recessive genes, one
from the father and one from the mother. What fraction of offspring will have
free and what fraction will have attached?
Let’s do another together:
FF
ff check for right combinations and ratios
If I look at you and see that you have free earlobes, does that mean you have
two genes for free earlobes? Nooooo. If I see that you have attached earlobes,
Let’s do another for tongue. There are 2 genes for tongue-rolling, one for and
one against. Which do you think is dominant?.
Try
RR
rr
Application /assessment:
1. If you can roll your tongue, what do you know about the two genes that you
have inherited? Explain.
2. If you cannot roll your tongue, what do you know about the two genes you
have inherited? Explain.
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3. Using a Punnett Square, can you show if it is possible to have another and a
father who can roll their tongues, but have children that cannot roll their
tongues? Explain.
4. Using a Punnett Square, can you show if it is possible to have another and a
father who cannot roll their tongues, but have children that can roll their
tongues? Explain.
5. Extra challenge: Create a Punnett Square that incorporates not one, but two
traits (tongue rolling AND earlobes). Hint: You will need a total of 16 cells in
your Punnett Square. Tell about the different kind of offspring that are
possible.
Closure &
Assessment:
(2 min)



So what did we learn today?--About ourselves, about genes, about
inheritance, about Punnett squares, about science?
Where are we going? To study the particular diseases that can be
inherited and what those patterns of inheritance are.
How did your partner help you learn today? What’s something you did
well together? Say thanks & something you appreciate about them.
1) recognizing our own and others’ worlds/ the knowledge construction process
Cultural
responsiveness:  Students will have opportunities describe inheritance patterns based on their own
experiences and observations. In this way, students will have the opportunity to
contribute their own ideas in the process of building scientific ideas. These
understandings will be the basis for building an understanding of a scientific
model.
 Biases about typical ways scientific knowledge is constructed are not addressed
in this lesson; however students engage in thinking about how they are learning.
 The strategy builds on what the teacher has learned from her students, in this way
the teacher will be responsive and flexible to student interests and
understandings.
2) developing relationships to form inclusive communities/ prejudice reduction &
equity pedagogy
 Groups of students will be monitored to make sure that all students have a chance
to participate. Students will also be encouraged to self-monitor.
 Students will be encouraged to build on each others’ ideas not compete with each
others’ ideas.
 The teacher will model how to honor students’ language and ways of
understanding as valuable contributions. The teacher will recognize student
contributions by using a strategy of “re-voicing” (stating student comments such
that other students can hear and add to student ideas) and take this a step further
by encouraging students to re-voice one another’s ideas.
3) providing access (to the culture of science and school) through curriculum and
instruction/ content integration
 All students should have equal opportunity to participate in the activity. Students
who are adopted will be encouraged to think of families they are familiar with or
to share “families” with a friend. Students who do not “remember” traits in their
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families will be grouped with adopted students so that adopted students do not
feel singled out.
 This lesson incorporates content from students’ home cultures.
 This lesson uses pictures of people from a variety of racial backgrounds.
4) critiquing, challenging, and changing the culture of school and school science/
empowering school culture and social structure
 This individual lesson does not challenge the typical school science structures.
However this lesson include strategies where students help author an scientific
understanding. Students are treated as having valuable contributions to the way
we understand science. If these strategies are used consistently students will start
to understand that science knowledge does not come from a textbook but rather
from the ways in which individuals make sense of the world around them.
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