BIOD27H3 Lecture : BGYB30H3 Lecture 22 Notes Reproduction and Development 2-Nov 24
11 Aug 2010
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BGYB30H3 Lecture 22 Notes
-sperm and egg come together to form a zygote with 23 pairs of chromosomes
-autosomal chromosomes develop into human body form
-Y chromosome stimulates development of male
-SRY gene is the sex determining region of the Y chromosome, causing male reproductive
organs
-absence of an X chromosome is fatal
-dµv[Çv}u causes an underdeveloped reproductive system, which leads to
x Short stature
x Heart problems
x Poor breast development
-}oÁ]Zdµv[Çv}u}voÇZÀ}vyZ}u}}u (XO)
-<o]v(o[Çv}uinvolves an extra X chromosome (XXY), causing males to develop
female sex characteristics such as
x Altered upper to lower body ratio
x Female pubic hair pattern
x Sparse body hair
-Z^µuo[Çv}u~yzzinvolves
x increased growth rate in childhood
x taller than average height
x learning disabilities
x acne
-XXYY syndrome involves the development of male and female characteristics, causing
x gynecomastia: development of breasts in males
x taller height
x mood swings
x intellectual disabilities
x low muscle tone
x low testosterone
x sterile
-Swyer syndrome/XY gonadal dysgenesis is an absence or mutation of SRY chromosomes
-females have no functional female gonads in Swyer syndrome
-differentiation of the gonads occurs during the 7th week of development in embryos
-bipotential gonads have a pair of Wollfian and Mullerian ducts
-SRY gene directs the medulla of the bipotential gonads to form testes
-testes secrete
x anti-Mullerian hormone to degenerate the Mullerian duct
x testosterone to convert Wollfian duct to develop into the male reproductive system
x DHT to cause the development of external genitalia and prostate gland
-absence of SRY gene causes development of female genitalia
-cortex of bipotential gonad develops into ovaries
-no testosterone means that the Wolffian ducts degenerate
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Document Summary
Sperm and egg come together to form a zygote with 23 pairs of chromosomes. Sry gene is the sex determining region of the y chromosome, causing male reproductive organs. @lzzlk causes an underdeveloped reproductive system, which leads to. l zzlkinvolves an extra x chromosome (xxy), causing males to develop female sex characteristics such as. ykzlkoinvolves increased growth rate in childhood taller than average height learning disabilities. Xxyy syndrome involves the development of male and female characteristics, causing. Swyer syndrome/xy gonadal dysgenesis is an absence or mutation of sry chromosomes. Females have no functional female gonads in swyer syndrome. Differentiation of the gonads occurs during the 7th week of development in embryos. Bipotential gonads have a pair of wollfian and mullerian ducts. Sry gene directs the medulla of the bipotential gonads to form testes. N anti-mullerian hormone to degenerate the mullerian duct.
