PHL243H1 Lecture 5: LEC5- Dimorphism in Sex and Gender Feb 3 2010
LEC5: Dimorphism in Sex and Gender
Feb, 3rd 2010
How many sexes are there?
! many ppl think there has to be 2 sexes b/c the underlying reality is dimorphism (2
sorts of gametes – big and small) (and 2 types of chromosomes ie. XX & XY)
Not all living things have 2 sexes
! hermaphrodites: ie. picture in first slide = great slug double fuck, 69!
12 Step Program
! 12 steps/processes/factors
! each step will probably lead to the next one but there is no absolute determinism
about it
! 3. if the hormones dont act
Factors largely relevant to sex
! ESS = isogametic gametes who are the same size, but one kind thought that they
can gain advantage by being smaller and the other one thought it will gain
advantage by being bigger (hence egg & sperm)
! K-type = typical of mammals
! r-type = insects
Chromosomes
! olympics determine sex via chromosomes
! for birds the males are homozygous while female is heterozygous
! hence males birds are the ones who lay the eggs
Fetal Hormones
! whether an XY chromosome fetus will develop male reproductive organs
! if there is no fetal hormones for this male chromosomes do not develop sex
organs
External Anatomy
! inefficient hormone production or a failure of receptors to pick up the signals
! fail to conform to chromosome
Gonadal Sex (Internal Functional Anatomy)
Physiological Reproductive Functions
! you might have organs but they can fail to function as you predicted via
chromosomes
Adolescent & Adult Hormones
www.notesolution.com
Document Summary
many ppl think there has to be 2 sexes b/c the underlying reality is dimorphism (2 sorts of gametes big and small) (and 2 types of chromosomes ie. xx & xy) hermaphrodites: ie. picture in first slide = great slug double fuck, 69! each step will probably lead to the next one but there is no absolute determinism about it. ess = isogametic gametes who are the same size, but one kind thought that they can gain advantage by being smaller and the other one thought it will gain advantage by being bigger (hence egg & sperm) k-type = typical of mammals r-type = insects. hence males birds are the ones who lay the eggs for birds the males are homozygous while female is heterozygous. whether an xy chromosome fetus will develop male reproductive organs if there is no fetal hormones for this male chromosomes do not develop sex organs.
