Your Mom has Big Feet, Will You Have Them Too?
How traits are passed from parents to offspring
create their own offspring and see how the traits they contribute
may or may not show up in the offspring, depending on what
genes the other parent contributes. In this way, students
will learn the many possible combinations that can be acheived
by combining a few simple traits in different ways.
activity allows students to move around and interact with
many other students. It includes writing and drawing, which
highlight different student strengths. The drawings provide
much amusement for the whole class.
best feature of this lesson is the built-in student self-evaluation
that results from multiple student pairings. Any student
with a shakey understanding of genetics will have over 10
opportunities to pair with other students and apply the
principles for genetics in a fun activity. Students will
have to teach each other and reach an agreement on the offspring's
is a first year teacher of Biology. She enjoys creative and
interactive methods of teaching that actively involve the
Location: Information Technology High School,
Long Island City, NY
If you have any questions regarding this activity, please
contact Chloe at: firstname.lastname@example.org
will be able to describe and apply the Mendellian principles of
genetics, which include dominance and recessiveness of genes. Students
will demonstrate how two parents contribute genes and how those
genes appear in their offspring.
Genes, Alleles, Dominance, Recessiveness, Chromosomes, Genotype,
Now (5 mins): Ask students to consider the following: Do you
have a gap in your front teeth? Can you roll your tongue? Do you
have a widow's peak? Are your earlobes free or attached?
Mendellian principles of genetics (10 mins): The basics of
these principles should have been covered in an earlier class, using
Mendel's pea-plant experiments as the core example. Stuents must
understand the principles of dominance, recessivness, what an allele
is and genotype & phenotype to do the activity. The class can
review these principles through 10 minutes of whole-class discussion
before doing a group activity (below).
Summary (5 mins): The key points & definitions should be
highlighted and visible on the board for reference during the following
(25 mins): Students will design their own chromosomes and then intereract
with other students (in pairs). Each pair will contribute a chromosome
that has 5 traits on it. The offspring that would result from each
chromosome pair is described in writing and by drawing. Because
each student pairs with many other students in the class, a large
variety of offspring will surface. See below for a full description
of this activity.
Summary (5 mins): Once each student has paired with every other
student, the resulting drawing and description of the offspring
should be pinned onto a wall for comparison. The class will get
a lot of laughs from the pictures and be able to check the accuracy
of the phenotypes based on the combination of alleles. The teacher
can randomly select 5 or so for the class to evaluate.
students should be seated in rows, with 2 students per table, but
other seating arrangements will work also. Each student must be
numbered 1 or 2.
is given an index card which will serve as a chromosome. Each chromosome
has 5 traits pre-printed on it (or the kids can copy this off the
board) as follows:
1 = Gene for eye color:
2 = Gene for hair color:
3 = Gene for hair texture:
4 = Gene for dimples:
5 = Gene for height:
At the teachers
instruction, each student will write in a chosen allele (a specific
gene for each trait) for each of the 5 genes. For example, a student
1 = Gene for
eye color: BLUE
2 = Gene for hair color: BROWN
3 = Gene for hair texture: CURLY... etc
should display on the board and point out that certain genes (alleles)
are dominant over others. For example, brown eyes are dominant over
blue eyes, so any offspring with a brown-eye gene will have brown
eyes, even if the other gene contributed is for blue eyes.
Then, in 2 minute
intervals (the teacher can blow a whistle to indicate the next move)
each student numbered '2' must get up, move to the next table (where
a number '1' is seated) and compare chromosomes. Based on the chromosome
pair at that table, what will the offspring look like? Are there
2 dominant genes, one dominant and one recessive, or 2 recessive
genes? Students must write the gene combination, describe the phenotype
(physical characteristics) and draw the offspring.
continue to move from table to table until every number 2 student
has paired their chromosome with each number 1 student. The resulting
drawings can be posted on the wall and compared (they will also
provide a lot of amusement!).
chromosomes and offspring can be kept for a future class in which
other Mendellian principles are covered. For example, incomplete
dominance or codominance can be taught, and students can use their
chromosomes and resulting offspring as the basis for exploring these
principles. An activity where more genes are added and new offspring
are made is an option.
everone in your immediate family and describe them in terms of the
5 traits we used in today's activity. Include your mother, father
and any siblings. Then, for each person, write the possible gene
cominations that they may have received from their parents. For
example, if your dad has blue eyes, both of his parents must have
given him an allele for blue eyes, since blue-eye alleles are recessive.
But, is it possible that his parents had brown eyes? Yes, because
they may have each had one recessive allele for blue eyes and one
dominant allele for brown eyes.
Students will understand and apply scientific concepts, principles
and theories pertaining to the living environment.
Cover the basics of genetics in an introductory class and use this
class as a review and application session.
This class is
designed for a 1-hour block scheduling class but can be adapted
to a 42 minute class by using 2 class periods.
card 'chromosomes' and worksheets for the students to draw and describe
their offspring will also come in handy.