[G] Genetic factors Flashcards
How many pairs of chromosomes does everyone have?
23.
What are normal female chromosomes?
XX.
What are normal male chromosomes?
XY.
Which gene has been suggested to be involved in triggering the development of testes?
The SRY gene.
What did Koopman find?
If the SRY gene is implanted into a normal female mouse, it develops into a male mouse.
What did Swaab find?
5 SDNs, areas in the brain which are different in males and females. In the brains of 11 transsexual males, they had female SDNs.
What did Gorski find?
The SDN was also found in rats, and is bigger in male rats as it is in male humans.
What did the Olympics Committee do in 1992?
Used the presence of the SRY gene to determine and verify gender, any females who had the gene could not participate as females.
What happened to David Reimer?
He was born as one of twins, and had his penis burnt off during routine circumcision. Doctor Money suggested David was brought up as a girl called Brenda as he believed all children were gender neutral until two years of age. He was never happy as a girl and suffered severe depression. When he found out the truth, he began living as David and had hormonal treatment to restore his original gender.
What did Reiner and Gearhart find?
16 genetic males who had almost no penis were studied, 14 were raised as females, 8 underwent gender reassignment surgery by age 16. The two raised as males stayed as male.
Who did Goldwyn study?
Mr Blackwell,a hermaphrodite who had a small vaginal opening in addition to a penis. He was taken to be a boy but developed breasts at 14. It was found that he had an ovary on one side of the body and a testicle on the other, and if his internal ducts had been connected differently he would have been able to impregnate himself without having any control over this.
Who did Imperato-McGinley et al study?
The Batista family, where ten XY children were born with exceptionally small penises and raised as girls until puberty at which point they easily transitioned into male life.
What is Turner’s syndrome?
A child is born with only one X chromosome, resulting in female external appearance but making them infertile.
What is Klinefelter’s syndrome?
A child is born with an extra X chromosome.
Give three strengths of the genetic explanation of gender development.
- Supporting research from many individuals.
- SRY gene being found in rats shows that animal studies are sometimes applicable to humans.
- Practical application by Olympics Committee.
