Using the model of a Using the model of a Punnett Square to Punnett Square to

predict offspring ratios predict offspring ratios

ObjectivesObjectives

► Objective 1: Students will know that Objective 1: Students will know that chromosomes have genes that control the chromosomes have genes that control the phenotype (appearance) of organismsphenotype (appearance) of organisms

► Objective 2: Students will calculate the Objective 2: Students will calculate the percentages of various types of potential percentages of various types of potential offspring based on a simple dominance offspring based on a simple dominance model and using a single trait. model and using a single trait.

► Objective 3. Students will extend the model Objective 3. Students will extend the model of the Punnett Square in order to apply the of the Punnett Square in order to apply the concept of simple dominance to new traits. concept of simple dominance to new traits.

Interactive Concept BuildingInteractive Concept Building

Attributes:Attributes:► ““just-in-time” instruction XXX-----XXXjust-in-time” instruction XXX-----XXX► Teacher-student & student-student discourseTeacher-student & student-student discourseGoals:Goals:► Help students interpret, understand, synthesize info Help students interpret, understand, synthesize info

they have been working with (build on their they have been working with (build on their experiences & language)experiences & language)

► Facilitate discussion with Questions & new info Facilitate discussion with Questions & new info (integrate student language & encourage cross-talk)(integrate student language & encourage cross-talk)

► Provide a bridge to scientific way of talking/thinkingProvide a bridge to scientific way of talking/thinking► Challenge students to return to activity armed with Challenge students to return to activity armed with

new knowledgenew knowledge

““Will your kids be Will your kids be able to roll their able to roll their

tongues?” tongues?”

Sperm + Egg = OffspringSperm + Egg = Offspring► We have been talking We have been talking

about the idea of sperm about the idea of sperm and egg getting together and egg getting together to create a new life. We to create a new life. We know that this happens know that this happens in both plants and in both plants and animals. In animals, the animals. In animals, the male contributes the male contributes the sperm, and the female sperm, and the female contributes the egg. In contributes the egg. In plants, the male part of plants, the male part of the plant contributes the plant contributes pollen, which acts like pollen, which acts like the sperm, and in the the sperm, and in the female part of the plant female part of the plant is the egg. is the egg.

Mysteries & InheritanceMysteries & Inheritance

► If we look at brothers or If we look at brothers or sisters who all come from sisters who all come from the same parents, do the same parents, do these brothers and these brothers and sisters all look exactly sisters all look exactly the same? So are we not the same? So are we not clones of our parents?clones of our parents?

► What are some What are some differences between differences between brothers or sisters who brothers or sisters who come from the same come from the same parents? parents?

More questionsMore questions

► If you have a mother who is 5 feet 5 If you have a mother who is 5 feet 5 inches tall and a father who is 6 feet inches tall and a father who is 6 feet tall, and they have four children, how tall, and they have four children, how tall do you think they should be? All tall do you think they should be? All the same? the same?

► Is it possible for a child to end up Is it possible for a child to end up shorter than both parents? Or taller shorter than both parents? Or taller than both parents?than both parents?

And what about…And what about…

►Have any of you seen a person who Have any of you seen a person who looks like they have the traits of one of looks like they have the traits of one of their grandparents but not the parent, their grandparents but not the parent, like the traits skipped a generation? like the traits skipped a generation?

►Do any of you have traits more similar Do any of you have traits more similar to your grandmothers or grandfathers to your grandmothers or grandfathers than your parents?than your parents?

To begin to understand how these kinds To begin to understand how these kinds of traits can be inherited, we have to of traits can be inherited, we have to go back to the idea of the sperm and go back to the idea of the sperm and the egg contributing to who we are.the egg contributing to who we are.

23+2323+23 46 Chromosomes 46 Chromosomes Female & MaleFemale & Male

►These paired chromosomes are These paired chromosomes are made up of thousands of sections made up of thousands of sections called genes. called genes. Each gene controls Each gene controls some kind of traitsome kind of trait, like , like color of color of hairhair, or , or color of eyescolor of eyes, or contribute , or contribute to height. to height.

There are about There are about 100,000100,000 genes genes

that make up the human body. that make up the human body.

Mother Father

What is interesting is that we can tell a little about what kind of genes we have by observing various traits in ourselves.

Which form of the gene is wins? loses?

Free (F) Attached (f)

Roll (R) Not Roll (r)

Beaker BabiesBeaker Babies

?

f f F F or

F f

F f

F

f

Male

Femal

e

Punnett Square

F FF F F fF f

f Ff F f ff f

Phenotype Ratio (what shows): 3:1 POSSIBLE Combinations of Genes

rrrr rrrr

rrrr rrrr

r r

r

r

Male

Femal

e

Phenotype Ratio (what shows): 4:0

Now to answer our question for the day…

Tasks for the day:Tasks for the day:► 1. If you can roll your tongue, what do you know about 1. If you can roll your tongue, what do you know about

the two genes that you have inherited? Explain. the two genes that you have inherited? Explain. ► 2. If you cannot roll your tongue, what do you know 2. If you cannot roll your tongue, what do you know

about the two genes you have inherited? Explain. about the two genes you have inherited? Explain. ► 3. Using a Punnett Square, can you show if it is possible 3. Using a Punnett Square, can you show if it is possible

to have another and a father who can roll their tongues, to have another and a father who can roll their tongues, but have children that cannot roll their tongues? but have children that cannot roll their tongues? Explain. Explain.

► 4. Using a Punnett Square, can you show if it is possible 4. Using a Punnett Square, can you show if it is possible to have a mother and a father who cannot roll their to have a mother and a father who cannot roll their tongues, but have children that can roll their tongues? tongues, but have children that can roll their tongues? Explain. Explain.

► 5. 5. Extra challengeExtra challenge: Create a Punnett Square that : Create a Punnett Square that incorporates not one, but two traits (tongue rolling AND incorporates not one, but two traits (tongue rolling AND earlobes). Hint: You will need a total of 16 cells in your earlobes). Hint: You will need a total of 16 cells in your Punnett Square. Tell about the different kind of Punnett Square. Tell about the different kind of offspring that are possible. offspring that are possible.

So what did we learn today?So what did we learn today?

►About ourselvesAbout ourselves

►About genesAbout genes

►About inheritanceAbout inheritance

►About Punnett SquaresAbout Punnett Squares

►About scienceAbout science

Where are we going? Where are we going?

To study the particular diseases To study the particular diseases that can be inherited & what that can be inherited & what those patterns of inheritance those patterns of inheritance

are…are…

How did your partner help you learn today?What’s something you did well together?Say thanks & something you appreciate about them.

For your microteaching…For your microteaching…

►What big ideas & their related concepts What big ideas & their related concepts are best suited for this strategy?are best suited for this strategy?

►What inquiry activity might they be What inquiry activity might they be doing as a context for using this doing as a context for using this strategy?strategy?

►How can I have the students participate How can I have the students participate in creating the bridge to this scientific in creating the bridge to this scientific concept?concept?

Female- Body Cell Female- Body Cell ChromosomesChromosomes

Male- Body Cell Male- Body Cell ChromosomesChromosomes