sex differences

Question 1

What are organisational effects

Answer 1

• effects on tissue differentiation and development

* permanent

Question 2

what are activantional effects

Answer 2

• effects that occur in fully developed organism; may depend on prior exposure to organisational effects of hormones
• transient

Question 3

what are the types of hormone action

Answer 3

organisational and activational effects

Question 4

What is sexual dimorphisms

Answer 4

(differences in anatomy, physiology and behaviour between males and females)

Question 5

what does Sexual differentiation in mammals depend on

Answer 5

organisational effects of hormones during development

Question 6

where is DNA present

Answer 6

DNA is present in the nucleus of every cell (except red blood cells)

Question 7

How many pairs of autosomes do humans have

Answer 7

22

Question 8

what is an autosome

Answer 8

doesnt determmine sex differneces

Question 9

Gametes are haploid… meaning…

Answer 9

just one copy of each chromosome

Question 10

Gametes fuse to create

Answer 10

diploid offspring

Question 11

What is gonadal

Answer 11

Undifferentiated ‘primordial’ gonads (yet to develop sex characteristics)

Question 12

what does SRY stand for

Answer 12

sex-determining region Y gene

Question 13

What happens to the ovary in early embryonic development

Answer 13

• ovary does not produce significant amounts of steroid hormones during embryonic development
• each part of the body develops according to its own intrinsic programme

Question 14

what hormone is produced in the testes that leads to mascullinises internal genitalia

Answer 14

Anti-mullerian hormone (AMH)

Question 15

what is testosterone

Answer 15

•	steroid hormone
fat-soluble, passes readily through cell membrane
•	primary androgen
•	synthesised by Leydig cells in testes
•	Sertoli cells produce AMH

Question 16

what does 5-alpha-reductase do

Answer 16

Testosterone is converted DHT. This is catalysed by enzyme 5-alpha-reductase. Females also have this enzyme but no testosterone to convert to DHT. DHT is a more potent form of testosterone.

Question 17

what does genotypic sex determine

Answer 17

gonadal sex

Question 18

what does gonadal sex determine

Answer 18

phenotypic sex

Question 19

what does AMH leadto

Answer 19

internal genitalia

Question 20

what does DHT lead to

Answer 20

external genitalia

Question 21

what does testosterone lead to

Answer 21

rest of body

Question 22

what does Further organisational effects of hormones at puberty lead to

Answer 22

• anterior pituitary releases growth hormone, gonadotropic hormone and adrenocorticotropic hormone (stimulates adrenal cortex)
• leads to development of secondary sexual characteristics (not present at birth)

Question 23

What do homicide rates show

Answer 23

• men kill men much more frequently than women kill women
• most victims and offenders are young men
• this pattern is stable across cultures and over time

Question 24

What was found with female guinea pigs wth testosterone

Answer 24

Female guinea pigs treated with testosterone when pregnant produce defeminised, masculinised daughters with male-typical behaviour

Question 25

what was found aboit Female rhesus macaques given testosterone as newborns

Answer 25

Female rhesus macaques given testosterone as newborns show male-typical behaviour as adults:
•	pursuit and mounting of other females
•	pelvic thrusting
•	post-ejaculatory behaviours
•	preference for female partners

Question 26

how mcuh larger are the Song control region in zebra finches in males than femalesz

Answer 26

5-6 times

Question 27

example of sexually dimorphic brain

Answer 27

Song control region in zebra finches
• 5–6 times larger in males than in females
• gets bigger in females given testosterone as hatchlings

Rat hypothalamus: sexually dimorphic nucleus of pre-optic area (SDN-POA)
• smaller in males castrated at birth
• bigger in females given testosterone at birth
• no effect of castration/testosterone treatment in adulthood

Question 28

how much heavier are male brains than female

Answer 28

On average male brains are 120–160 g (10–15%) heavier
Also heavier relative to body size
Difference present at birth despite equal body weights

Question 29

which sex is less strongly lateralised

Answer 29

female

Question 30

Parts of corpus callosum are bigger in right-handed than left-handed men; no such pattern for women

true or false

Answer 30

true