Sex

Question 1

What is a genotype?

Answer 1

A full set of genes that an organism possesses

Question 2

What are different genes organised into?

Answer 2

Chromosomes

Question 3

How many pairs of chromosomes does each of our cells (somatic) contain?

Answer 3

23

Question 4

What are the 23rd pair of chromosomes?

Answer 4

Sex chromosomes; produce our physical and behavioural characteristics

Question 5

What chromosomes does the female gene have?

Answer 5

XX

Question 6

What chromosomes does the male gene have?

Answer 6

XY

Question 7

What is the main androgen?

Answer 7

Testosterone

Question 8

What is the main estrogen?

Answer 8

Estradiol

Question 9

What are we the product of?

Answer 9

1) Genotype (XX or XY)
2) Action of sex hormones pre-natal
3) Proportion of sex hormones post-natal

Question 10

What does the Mullerian inhibitory hormone do?

Answer 10

All foetuses would result as female if it were not for this hormone, which inhibits the formation of the Müllerian ducts and the Wolffian ducts are retained

Question 11

When are androgens released and what do they do?

Answer 11

Pre-natal and in the first week post natal

- Leads to testes development

Question 12

How does the female hypothalamus release hormones compared to the male one?

Answer 12

Female = cyclically
Male = steadily

Question 13

What are gonadal hormones?

Answer 13

Act on the brain all through life

- Changes in levels change behaviour

Question 14

What is the size of the male INAH3 compared to females?

Answer 14

Twice as large in males

Question 15

What is the difference in the SCN in the male and female brain?

Answer 15

Has twice the no. of neurons in the male brain

Question 16

What is Turner’s syndrome?

Answer 16

Lack of sexual development in women

Question 17

What is CAH?

Answer 17

Abnormally high levels of circulating androgens that result in a masculine phenotype of XX individuals

Question 18

What is AIS?

Answer 18

Feminisation of XY individuals (not responsive to circulating levels of androgen)

Question 19

What happens if the genotypes and phenotypic sex of an individual are not aligned?

Answer 19

Variety of genetic mutations that result in ambiguous sexual phenotype

Question 20

What is sexually dimorphic behaviour?

Answer 20

When animal behaviours differ between the sexes

Question 21

How does a female rat adopt a lordosis posture?

Answer 21

Meditated by the ventromedial region of the hypothalamus which has many oestrogen receptors

Question 22

Other than copulation, what else can sexually dimorphic behaviours involve?

Answer 22

Many are designed to attract a potential mate

Question 23

What happens if there is a lesion to the ‘sex neurons’ in the hypothalamus?

Answer 23

Stops males from mating, but they continue to show interest in receptive females

Question 24

What is the difference between the hypothalamus and amygdala in regards to sex?

Answer 24

Hypothalamus = sexual behaviour
Amygdala = motivation

Question 25

What do lesions to the frontal lobe result in in regards to sex?

Answer 25

• Loss of inhibition about sexual behaviour

- Loss of interest in sexual behaviour (libido)

Question 26

What is erotomania?

Answer 26

People believe that another person is in love with them

- Frontal lobe damage can bring this about

Question 27

What could a lesion to the left DLPFC result in?

Answer 27

Aggressive sexual behaviour

Question 28

What is the intense reward of orgasm caused by?

Answer 28

Release of the excitatory neurotransmitter dopamine, then relaxation due to oxytocin

Question 29

What is the structure of oxytocin closely linked to?

Answer 29

Endorphins

Question 30

Who does better in tests of verbal fluency and why?

Answer 30

Women

- Evolution: Females left behind in social groups, communication important

Question 31

Who does better on tests of spatial reasoning?

Answer 31

Men
- Males have tended to range over larger territories than females (greater spatial abilities would have been advantageous)

Question 32

What did Slavic and Lindstrom show?

Answer 32

Gay women have asymmetric brains like straight men (geared to right hemisphere)
- Gay men have symmetric brains like straight women

Question 33

What did Slavic and Lindstrom find was different about the amygdala in gay women and straight men?

Answer 33

Connects more to sensorimotor system and basal ganglia; much more action related response
- Amygdala in gay men and straight women connects to areas of brain that manifest mood, fear, and anxiety