PHGY 214 Lecture Notes - Lecture 10: Mesonephric Duct, Paramesonephric Duct, Labioscrotal Swelling
28 Apr 2016
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Document Summary
Three levels of differences between males and females: genetic (xx vs xy) - fertilization, gonadal (ovary vs testes, phenotypic. Genetic: depends on combination of sex chromosomes at time of fertilization, oocytes are identical in terms of genetic makeup, sperm come in two types, x and y. Gonadal: presence or absence of y chromosome determines gonadal differentiation (testes when y is present) Phenotypic: presence or absence of testosterone determines external genitalia (vagina vs penis, post pubertal secondary sex characteristics (breast development, hair pattern, body habitus) determined by estrogen vs testosterone. Somatic cells: contain 46 chromosomes (diploid number, can be sorted into 23 homologous pairs (one from mother, one from father) Gametes (sperm and egg: have 23 chromosomes (haploid number, contain one member of each homologous pair of chromosomes as a result of meiosis. Meotic division of occyte will produce identicle cells. But for sperm will roduce x or y sperm.
