LT2 - Genes and Hormones Flashcards
Where are Hormones produced?
In the endocrine glands e.g. testes or ovaries
What does (MIS) Anti-Mullerian do?
Prevents the further development of female sex organs.
What does XX mean?
A girl
What does the presence of a Y mean?
A boy
Who always passes on an X chromosome?
The female mother in her egg. the Male father passes on an X or Y chromosome in his sperm.
The Gonads (sex organs) develop at how many weeks?
6 weeks but at this point there is no difference between the developing sex organs of male or females.
What gene on the Y chromosome produces protein that causes the male foetus to develop?
The SRY gene.
What happens if the Y chromosome isn’t present?
The genes will cause female organs to grow.
Why is David Reimer’s testimony a supportive evidence?
He provides the argument that biological factors influence gender development. David was born a male (XY) biologically and physically. but was raised female. however, David felt masculine and did not feel he was a girl and was extremely unhappy, as a result he decided to return to male. * This suggests that despite his unhappy upbringing as a female his genetic status was a male (XY) was strong enough to override this, showing the influence of biology.
What is Klienfelters syndrome and why does that further support the role of gender development?
Its an abnormality that affects men who are born XXY. the extra X accounts for their small testes, low testosterone levels and excessive breast tissue.
How is the case study of Daphne Went Opposing evidence for Gender development?
She was a pseudo-hermaphrodite who was born chromosomally male (XY) but with the physical appearance of a female. Daphne was also successfully raised a female, therefore refuting the genetic explanation of gender development.
What do Hormones do?
Carry chemical messages in the bloodstream, but more slowly than neurotransmitters. and produced by the endocrine system.
What are female hormones?
Oestrogen and Progesterone
What androgens such as testosterone?
Male Hormones produced in the testes.
If the Y chromosome is present after 6 weeks of foetal development what happens?
The HY protein antigen hormone is released which encourages the development of testes over ovaries.
What happens after 6 weeks after foetal development?
The testes release male sex hormones such as testosterone triggering the development of the penis.
what happens with females without the presence of the Y chromosome?
no male hormones released female sex organs develop e.g. ovaries and vagina. (absence of male hormones, rather than the presence of female hormones).
How do hormones play a role in secondary sexual development during puberty?
In males more testosterone is released resulting in males producing sperm and growing facial hair.
what happens when more oestrogen is released in females at puberty?
Females grow, grow breasts, and fatty tissue to be deposited on the hips.
What are reliable supporting evidence for hormones?
When pregnant female rats are injected with the male hormone testosterone, female baby rats exhibit male behaviour e.g. trying to mate with other female rats. *This suggests that the presence of testosterone (male hormones) account for different sex behaviours.
why is there support from pseudo-hermaphrodites?
in androgen insensitivity syndrome a foetus that is chromosomally male, as in the case of Daphne Went. Such a syndrome supports the argument that prenatal exposure to certain hormones determines gender development, as it appears that hormone exposure can override genetic sex.
Why can’t animal studies always be generalised to humans?
For example, in the case of hormones, women are different to animals in the way their sexual cycle causes menstruation, *Few animals experience blood loss in the same way. this shows that a humans hormonal system is different to an animals.
