Source: http://media.bonnint.net/dado/oss-trav/0/1/143.jpg

This activity is designed for you to understand how probability plays a factor when it comes to heredity.  As I mentioned earlier in the previous post, Punnett square allows scientists to make predictions about various genetic problems.  It shows the probability of what might occur.  If you recall from your math class, probability is the chance of something occurring.  For instance, if you flip a coin 100 times, you would expect to get 50 heads and 50 tails.  However, after tossing your coin for 100 times, you actually ended up getting 40 heads and 60 tails instead.  Therefore, Punnett square is only a prediction of the chance.

If you have a sibling, invite your sibling to join you for this activity because you will need someone to record data for this activity.  Here is what you needs: a bag of M&M chocolates and two paper bags.  Pick two colors of M&M from your bag of chocolate.  For example, red and white.  Put 15 red M&M and 15 white M&M into one paper bag and label this paper bag as "Female".  Get another paper bag and put 15 red and white M&M into this bag again.  Label this bag "Male".  These two paper bags with red and white M&M chocolates will represent your heterozygous parents (Rr X Rr).

Have your sibling and yourself reach into each paper bag at the same time and pull out one of the M&M chocolates from the bag.  Remember, the only possibilities that can be made from this selection are: RR (homozygous red), Rr (heterozygous red), or rr (homozygous white). Record genotype and phenotype in the data table then return the chocolate back into the bag.  Repeat the drawing process for another 14 times with a total of 15 trials.

Your data table should look like this:
Trial                  Offspring's genotype                      Offspring's phenotype
-------------------------------------------------------------------------------------------------------------------
1                        RR                                                      Red
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Keep your data table for now and we will wrap up this activity in the next blog post.

P.S: You may now eat your chocolates after you record all the data!

 


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    Author

    Ms. Pan is a 7th grade Science teacher at XXX Middle School. 

    Ms. Pan is both a scientist and an educator, but she likes the role of a teacher more than anything else. 

    The purpose of this blog is to provide online learning discussion and stimulate thinking prior classroom activities.
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    For students, please check this blog on a daily basis to participate in discussion.
    For parents, please check this blog on a regular basis to see what your children are learning in the classroom.

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