bio inheir

1. Imagine that you are a doctor in a maternity ward. During your last shift, 20 babies were born. 10 had blue eyes, and 10 had brown eyes. Remember genotypes are the two alleles given for each trait, written with a letter.  For this activity B =brown eyes b= blue eyes.  Phenotypes are the physical appearance of the trait.

What percentage of babies have Brown and Blue eyes (to find percent divide the total number of blue-eyed babies by the total number of babies born.  You should get a decimal number.  Just use the first two numbers as the percent.  If your answer is .25 you would have 25%).

2. Imagine that you are a doctor in a maternity ward. During your last shift, 20 babies were born. 10 had blue eyes, and 10 had brown eyes. Remember genotypes are the two alleles given for each trait, written with a letter.  For this activity B =brown eyes b= blue eyes.  Phenotypes are the physical appearance of the trait.

Which color of eyes is dominant?  How do you know this?  What does this mean in terms of inheritance?

3. Imagine that you are a doctor in a maternity ward. During your last shift, 20 babies were born. 10 had blue eyes, and 10 had brown eyes. Remember genotypes are the two alleles given for each trait, written with a letter.  For this activity B =brown eyes b= blue eyes.  Phenotypes are the physical appearance of the trait.

Considering what you know about dominant and recessive genes, what are the possible genotypes for brown-eyed babies?  What are the possible genotypes for blue-eyed babies?  Explain how you came to this response making sure to discuss dominant and recessive genes.

4. Imagine that you are a doctor in a maternity ward. During your last shift, 20 babies were born. 10 had blue eyes, and 10 had brown eyes. Remember genotypes are the two alleles given for each trait, written with a letter.  For this activity B =brown eyes b= blue eyes.  Phenotypes are the physical appearance of the trait.

Considering the possible genotypes you listed in question 3, what traits would the parents of brown-eyed and blue-eyed children have to have?  Explain your answer by creating a table like the one below and completing the Punnett square to show the genotypes. 
*Create a table by clicking on the “Insert Table” icon, which looks like a grid, on the far right*

Genotypes
: 

Phenotypes
: 

5.  In the previous scenario, you looked closely at the effect of dominance and recessive genes.  In this scenario, we will look at codominance.  Codominance means that the alleles inherited from the parent gene are both dominant.  Thus, the traits from both alleles are expressed. Look at the example below, we have one brown parent (RR) and one white parent (WW). All the offspring are White with Brown spots (RW).

Looking at the Punnett square above, how does this demonstrate codominance?