Role of chromosomes and hormones

Question 1

what are chromosomes

Answer 1

46 (23 pairs) biological threads (DNA) carrying the genetic information (genotypes) that code for phenotypes

Question 2

which pair of chromosomes is sex based off of

Answer 2

23rd pair

Question 3

what is the SRY gene

Answer 3

sex determining region of the Y gene - controls whether gonads become ovaries or testes

Question 4

which chromosome determines the sex of a child

Answer 4

the y chromosome

Question 5

when does the SRY gene affected the embryo

Answer 5

6 weeks into pregnancy

Question 6

how does the SRY gene change the embryo

Answer 6

causes the gonads to develop as testes which produce the male sex hormone testosterone causing male external gentalia

Question 7

what are the gonads

Answer 7

sex organs

Question 8

what happens if the embryo has no y chromosome

Answer 8

no SRY gene so gonads develop as ovaries

Question 9

can a woman be born with a y chromosome

Answer 9

yes but the SRY gene will be missing/not activate from the Y chromosome so foetus grows as a woman

Question 10

what are hormones

Answer 10

bio-chemical messengers in the bloodstream

Question 11

what is an androgen

Answer 11

a male sex hormone

Question 12

what is the proportion of testosterone in men vs women

Answer 12

10 times more in men than women

Question 13

what is the role of testosterone in sex

Answer 13

development of a male foetus in 8-24 weeks of pregnancy, secondary sexual charactertistics

Question 14

when does testosterone start being produced in a foetus

Answer 14

8 weeks

Question 15

what is the role of testosterone in gender

Answer 15

affects the hypothalamus, leading to masculinisation of the brain

Question 16

what features are associated with the masculinisation of the brain

Answer 16

higher levels of aggression, competitiveness, development of areas of brain linked to spatial tasks

Question 17

what difference in the hypothalamus is there between men and women

Answer 17

the sexual dimorphic nucleus is bigger in males

Question 18

what is testosterone

Answer 18

steroid hormone - androgen, male sex hormone

Question 19

what is the main important feature of testosterone

Answer 19

it begins prenatally

Question 20

what is oestrogen

Answer 20

female sex hormone, promotes secondary sexual characteristics

Question 21

what is the role of oestrogen in sex

Answer 21

regulation of menstrual cycle, develop secondary sexual characteristics, diminishing levels are associated with the menopause

Question 22

what is the role of oestrogen in gender

Answer 22

PMT - premenstrual tension = feelings of emotionality, irritability, irrational
- feminisation of the brain = sensitivity, co-operation
- high level after birth = maternal caregiving

Question 23

what is oxytocin

Answer 23

‘love hormone’ - promotes feelins of bonding in men and women

Question 24

where is oxytocin produced

Answer 24

pituitary gland

Question 25

is the affect of oxytocin greater in men or women

Answer 25

women

Question 26

why is the affect of oxytocin greater in women

Answer 26

synergies with oestrogen to enhance each's effects

Question 27

what is the role of oxytocin in sex

Answer 27

- stimulates lactation in women - facilitates childbirth (contractions) - dampens fight or flight response (reducing effect of stress hormone cortisol)

Question 28

what is the role of oxytocin in gender

Answer 28

- pair bonding behaviour for both genders - female social behaviour in mate selection (nesting behaviour = preparation for new offspring)

Question 29

what happens to oxytocin during sex

Answer 29

increase five-fold - drops immediately in men after orgasm

Question 30

what effect does testosterone have on oxytocin

Answer 30

it dampens the effect of oxytocin

Question 31

what response does oxytocin trigger in women in times of stress

Answer 31

tend and befriend response

Question 32

why did the tend and befriend response evolve in women

Answer 32

to protect their young and form protective alliances with other women

Question 33

what are the two atypical sex chromosome patterns

Answer 33

- klinefelter's syndrome - turner's syndrome

Question 34

which gender does klinefelter's syndrome occur in

Answer 34

men

Question 35

which gender does turner's syndrome occur in

Answer 35

women

Question 36

what chromosomes does a person with klinefelter's have

Answer 36

men get an extra X chromosome so the normal XY pair becomes XXY

Question 37

what are the physical characteristics of klinefelter's syndrome

Answer 37

- small testes - lack facial and pubic hair - broader hips - infertility - development of breast tissue

Question 38

what are the psychological characteristics of klinefelter's syndrome

Answer 38

- poor language and reading skills - dyslexia - shy - lack of interest in sex - handle stress badly - get emotional

Question 39

what chromosomes does a person with turner's syndrome have

Answer 39

women with only one complete X chromosome (second is either missing or incomplete)

Question 40

what are the physical characteristics of a person with turner's syndrome

Answer 40

- sterile - no period - webbed neck - low set ears - wide chest with no boobs

Question 41

what are the psychological characteristics of a person with turners syndrome

Answer 41

- high verbal and language skills - low visual ability - socially immature - bad spatial visual memory and bad maths