Sex, Genes, and Gender

femaleIntroduction - Even before you were born, your parents wondered whether you were going to be a boy or a girl. Most of the time, it's pretty obvious when a baby is born what their sex is - boy or girl. From the moment you were identified as one or the other, your parents planned accordingly. Girls got pink blankets and dolls, boys got the blue blanks and the fire trucks. As we learn more about genetics, the line between male and female has become somewhat blurred.

Question for Thought: In a real life scenario a thirty year old woman found out she was born a boy. Due to a tragic accident at the hospital, the baby boy's genitals were damaged and the doctors and family decided that it was best to raise the boy as a girl and do early gender reassignment surgery. As the boy (now a girl) grew up, she always felt she was different, and had bouts of depression and suicidal thoughts. You can find more about this story at "The Boy Who Lived as a Girl" -

Do you think that the family made a good choice for David? Why or why not?

Why Do You Need a Y?

It was understood that if a person had the Y chromosome, then that would indicate that the person was male. We assumed that until a curious case developed involving gender testing in the olympics. Follow this interesting case to learn more about why the Y isn't all you need to be a male. -Go to "Gender Testing of Female Athletes"

1.   Historically, why was gender testing implemented?


2.  What were the early gender tests like? 

3. How is sex and gender categorized (name 2)?


4.  Read Jane Doe’s History and view here Karyotype.

Based on a physical exam, did you think Jane was male or female? Defend your choice.


Based on a karyotype, did you think Jane was male or female? Defend your choice.


5.  What does it mean that an embryo at 6-7 weeks is “bipotential”?


6.  What does the SRY gene do?

7. After tests confirm that Jane has a functional SRY gene, did you think Jane was male or female


8.  What is CAIS and what does it do to the person who has it?


9.  How does a person get CAIS?  

10. Should female athletes with CAIS be disqualified?  Why or why not?