sex

1) Chromosomes: XX or XY 2) gonads: ovaries or testis 3) hormones: mostly from the testis 4) external reproductive anatomy: vulva or penis 5) internal reproductive anatomy (beyond the gonads) It is also correct to say that sex is based on three factors: chromosomes, hormones, and sex organs (which includes 2, 4, and 5).

Gonads are internal reproductive anatomy, but they develop from a distinct embryonic signaling cascade.

Y chromosome

when males and females of the same species have characteristics that differ beyond their sex organis. it comes from genetic and hormonal differences before and after birth. subtle or obvious differences, start at birth or puberty, differences in size, weight, color, behavior, cognition, etc.

the male and female differ so much they don’t appear to be the same species. female is a whole animal, the male is a tiny, rudimentary creature that attaches to the female parasitically like a sperm-producing appendage.

reproductive behavior, including courting, mating, parenting and most forms of aggression.

true

expressions of the cultural and biological characteristics that are associated with masculinity and femininity.

the behaviors and attitudes deemed typical, appropriate, or desirable for people of a given sex or gender.

someone’s personal sense of their own gender.

Opinions about masculinity and femininity (and racial categories) vary across cultures and across generations in a manner that is independent of biology, which indicates that gender (and race) are socially constructed, as opposed to being solely determined by biology. Biological factors influence social constructions, but strong cultures can mask or exaggerate biological differences.

the process of learning and teaching appropriate ways to behave in society. We pre-emptively encourage/discourage certain behaviours when socializing children to ensure their behaviours are congruent with our values and the dominant culture. strong disagreement these days about whether certain expressions of gender are healthy or toxic, whether they should be encouraged or discouraged.

Gene-environment interactions give rise to behaviour. Given that males and females have different genes, they may benefit from having different environments: different customs, laws, schools, sports teams, jobs, hobbies, lifestyles, etc. But ultimately this is a judgement call. We make judgement calls based on our cultural values. We can now sequence a person’s genome and assess overall brain activity with fMRI, but all this data typically tells very little about how the person will act, how intelligent they will be, and how good they will be at a particular job. evident that very different brains can have similar levels of intelligence.

females: ovaries males: testis

specialized cells produced by gonads. ovaries produce ova (egg cells), testis produce sperm.

23 pairs (46 total) 23 from mother 23 from father

23 chromosomes in total (some from the mother’s set and some from the father’s set) gametes only have one sex chromosome (X or Y) as they have only one version of every chromosome.

one pair of chromosomes, they usually determine the organism’s sex. They come in X and Y varieties.

all embryos develop precursor cells for both the male and female sex organs. at the end of the first month, there will be cells that make up the undifferentiated gonads, müllerian system and wolffian system.

embryonic precursor of ovaries/testes

embryonic precursors of internal female sex organs

embryonic precursors of internal male sex organs

if the SRY gene is present (typically on the Y chromosome), the gonads develop into testes. In the absence of SRY gene, two XX chromosomes trigger the gonads to develop into ovaries. Then, the presence (or absence) of hormones from the testis cause either the Wolffian (or Müllerian system) to develop while the other system withers away.

the SRY gene on the Y chromosome causes the gonads to develop into testes. this gene triggers testes to develop even when it is found in combination with two (or more) X chromosomes (e.g., XXY)