The role of chromosomes and hormones in sex and gender

Question 1

Chromosomes

Answer 1

X-shaped bodies that carry all the DNA for an organism

Question 2

Hormones

Answer 2

Body’s chemical messengers which travel through the body and influence many processes

Question 3

Intersex

Answer 3

An individual who is neither distinctly male or female because of a mismatch between, for example, chromosomes and genitals

Question 4

Typical chromosome patterns

Answer 4

Sex chromosomes determine and individual’s sex. In females, this pair is XX and in males, this pair is XY. There is usually a link between an individual’s chromosomal sex and their internal and external genitalia.

Question 5

Atypical sex chromosome patterns

Answer 5

Klinefelter’s syndrome - XXY. Individual is born with a penis, but physically look less masculine due to reduced testosterone.
Turner’s syndrome - XO. Individual is born with a vagina and womb, but may have a lack of monthly periods due to underdeveloped ovaries.

Question 6

Testosterone

Answer 6

Affects development of genitalia prenatally. Also affects brain development both prenatally and later in childhood. Surge of testosterone is also responsible for secondary sexual characteristics such as facial hair or deepening of voice

Question 7

Oestrogen

Answer 7

Default gender is female - a genetic male will develop as female if not exposed to testosterone. Plays a major role from puberty onwards promoting secondary sexual characteristics and directing the menstrual cycle

Question 8

Oxytocin

Answer 8

Produced in the pituitary gland and evokes feelings of commitment and calmness. Important for breastfeeding because it causes milk to flow in a lactating mother. Dampens the fight or flight response.