Download DO NOW: Have you ever heard that more guys are color blind than

DO NOW:
Have you ever heard that more guys are color blind than girls? If color blindness is a genetic trait, then why do
more guys get it than girls? Does sex matter? Why would sex matter in terms of how a trait is inherited?
CLASSWORK:
PART A:
RESEARCH –
 What is Hemophilia?
 How is Hemophilia treated?
 What is a Pedigree Chart?
 How do you read a Pedigree Chart?
 Define: male karyotype, female karyotype
PART B - Click on the following icon of a pedigree chart of a Royal Family, and use it to refer to in order to
answer the following questions. (If the icon doesn’t work, go to the LINKS section of my schoolnotes page to
view it.)
1.
2.
3.
4.
5.
6.
Which individuals are carriers of hemophilia in this family?
Which individuals have hemophilia in the family?
What trends or patterns do you see in who gets this genetic disease?
Why might you see the patterns you see?
What differences do you see between female chromosomes and male chromosomes?
Which chromosome do you think the gene for hemophilia is on?
PART C – Click on the following icon of the male karyotype and female karyotype and use it to refer to in
order to answer the following questions. (If the icon doesn’t work, go to the LINKS section of my schoolnotes
page to view it.)
Male Karyotype
Female Karyotype
1. How many pairs of chromosomes are there for males and for females?
2. What is different about the male and female kayrotypes?
3. Which chromosome do you think the recessive hemophilia gene is located on? Why?
PART D – GROUP WORK
1.
Refer to the Punnett Square for sex-linked traits in the chapter. Prove your answer to #3 from Part C
with a Punnett square that shows a cross between Prince Albert and Queen Victoria (at the top of the
pedigree) and what their possible offspring could be like (specify sex and whether they have the disease
or don’t have the disease or are a carrier for the disease).
PART E : Sex – Linked Traits HW
(Use Punnett square to solve or explain questions 1-4.)
1.
2.
3.
4.
5.
What is the chance that Leopold and Helen will have a male child with hemophilia?
What is the chance that they will have a female child with hemophilia?
What is the chance they will have a female child who is a carrier?
Can males be carriers? Why or why not?
Where do you think Queen Victoria got her recessive gene? (there is more than one possible answer)