AO1

• WHAT IS SEX CHARACTERISED BY?

  23rd pair of chromosomes (contain instructions about sex)

  -> FEMALE: XX

  -> MALE: XY
• WHAT DO GENES OF THE SEX CHROMOSOMES DO?

  determine levels of various hormones
• CHANGES IN MALES AND FEMALES IMMEDIATELY AFTER CONCEPTION AND AFTER FOETUS DEVELOPMENT?

  • immediately after conception, external genitalia of male and female look the same
  • as a foetus develops the internal genitalia of male produce testosterone/ internal genitalia of females produce oestrogen and oxytocin
• WHAT IS TESTOSTERONE?

  androgen
• WHAT IS AN ANDROGEN?

  hormone that causes penis development
• WHAT DO HIGHER LEVELS OF TESTOSTERONE CAUSE?

  male behaviours, e.g. aggression
• WHAT DOES OESTROGEN AFFECT?

  menstrual cycle and reproductive system
• WHAT DO HIGHER LEVELS OF OESTROGEN CAUSE?

  female behaviours, e.g. emotionality
• WHAT DOES OXYTOCIN AFFECT?

  nurturing and maternal behaviours
• DIFFERENCES IN OXYTOCIN BETWEEN MALES AND FEMALES?

  produced in larger quantities in women
• WHAT ELSE IS GOVERNED BY CHROMOSOMES?

  sex differences in brain development

  -> e.g. sexually dimorphic nucleus in hypothalamus is 2.5 times larger in males than females