Gender: chromosomes and hormones

Question 1

how many chromosomes do we have

Answer 1

46

Question 2

which pair of chromosomes determines sex

Answer 2

23rd

Question 3

state female and male chromosomes

Answer 3

female: XX
male: XY

Question 4

how chromosomes determine sex

Answer 4

All normal egg cells produced by a human ovary have an X chromosome
* Half the sperm carries an X chromosome and half a Y chromosome
* sex is determined by the sperm that fertilises the egg cell
* The baby will be a girl if the fertilising sperm carries an X chromosome and a boy if it carries a Y
chromosome.

Question 5

what gene does the Y chromosome carry

Answer 5

‘sex determining region Y’ (SRY)

Question 6

function of the SRY gene

Answer 6

The SRY gene causes testes to develop in an XY embryo. These produce androgens (male sex hormones).
* Androgens causes the embryo to become a male, without them the embryo develops into a female

Question 7

define hormones

Answer 7

chemical substances secreted by glands throughout the body and carried in the bloodstream

Question 8

when are hormones produced

Answer 8

in the womb, they affect brain development and production or reproductive organs

in adolescence, a surge of hormones during puberty leads to secondary sexual characteristics
eg: pubic hair

same sex hormones are present in men and women, but there are different amounts and different effects

Question 9

effects of testosterone

Answer 9

controls development of male sex organs during foetal development

Question 10

If a genetic female produces high levels of testosterone during foetal development, what would be the
outcome?

Answer 10

male sex organs will form

Question 11

If a genetic male produces no testosterone during foetal development, what would be the outcome?

Answer 11

no male sex organ will appear

Question 12

evolutionary explanation of high testosterone

Answer 12

high levels of
testosterone is also linked to aggression because it is adaptive
Aggression towards rivals allows males to complete for the opportunity to mate with a fertile female

Question 13

AO2: Nanne Van De Poll et al study

Answer 13

Nanne Van De Poll et al showed that female rats who had been injected with testosterone became more physically and
sexually aggressive

Question 14

effcts of oestrogen

Answer 14

determines female sexual characteristics and menstruation

Question 15

explain oestrogen and PMT

Answer 15

Oestrogen causes some women to experience heightened emotionality and irritability during their menstrual cycle. This is referred to as premenstrual tension (PMT) > people have questioned this being a diagnosable disorder and argue its an ‘over-medicalisation’ of women

Question 16

effects of oxytocin

Answer 16

stimulates lactation, making it possible for mothers to breastfeed their children.
It also reduces the stress hormone, cortisol and facilitates bonding
it is released in massive quantities during labour and after childbirth and makes new mothers feel ‘in love’ with their baby

Question 17

how does the fact that men produce less oxytocin create sex role stereotypes.

Answer 17

suggests that men lack interest in intimacy and closeness within a relationship

Question 18

AO3: research to support

Answer 18

evidence that chromosomes and hormones determine gender
eg:: David had his penis burnt of in an accident as a baby, his parents decided to raise him as a girl following their doctors
advice. As David grew older he became seemingly depressed, when his parents finally told him of his true gender he immediately “changed” back to a male, although initially he was relieved to find out the trauma of his childhood lead David
to take his own life.
supports influence of chromosomes as he was nurtured as a girl but his biological status was more important

Question 19

AO3: research against

Answer 19

Mead researched a remote tribe unaffected by western norms, they had the opposite gender roles to that of
westernised societies, for instance, the males were perceived to be more decorative and domestic whereas the females were the “hunter gatherers”, they would make the important decisions in the village
gender roles are inconsistent across cultures which suggests gender doesn’t have a biological basis

Question 20

AO3: evidence for testosterone

Answer 20

Male hypogonadism is a condition caused by a man’s testes failing to produce normal levels of the male sex hormone, testosterone.
Wang et al gave 227 hypogonadal men testosterone hormone therapy for 180 days. Significant changes in body shape, muscle strength, sexual function and libido were observed

shows that testosterone exerts a powerful and direct influence on male sexual arousal as well as physical development

Question 21

AO3: reductionist

Answer 21

reduces gender to hormones and chromosomes which is biological reductionism
ignores other factors
eg: psychodynamic approach suggests gender is due to identification with a same-sex parent
weakness as it ignores all other factors