Atypical sex chromosome patterns

Question 1

Atypical sex chromosome patterns

Answer 1

any sex chromosome pattern that deviates from the usual XX/XY formation
└tends to be associated with a distinct pattern of physical and psychological symptoms

Question 2

Atypical sex chromosome patterns

parts

Answer 2

Klinefelter’s syndrome

Turner’s syndrome

Question 3

Klinefelter’s syndrome

Answer 3

a syndrome affecting males, genotype has an extra X chromosome (XXY)

Question 4

Klinefelter’s syndrome

how many people it affects

Answer 4

└affects 1-2/1000 people

└2/3 people are not aware they have it

Question 5

Klinefelter’s syndrome

physical characteristics

Answer 5

└reduced body hair
└breast development at puberty (gynecomastia)
└rounding of body contours
└long limbs
└underdeveloped genitals
└clumsy 
 └susceptible to female health problems
  └e.g. breast cancer

Question 6

Klinefelter’s syndrome

psychological characteristics

Answer 6

└poor language skills and reading ability
└passive, shy
└lack interest in sexual activity
└problems with memory and problem solving

Question 7

Turner’s syndrome

Answer 7

a syndrome affecting females, genotype has one less X chromosome (X0)

Question 8

Turner’s syndrome

how many people it affects

Answer 8

└affects 1/5000 people

Question 9

Turner’s syndrome

physical characteristics

Answer 9

└don’t have a menstrual cycle  (amenorrhoea)
└sterile 
└shield chest, no breasts
└low set ears
└webbed neck

Question 10

Turner’s syndrome

psychological characteristics

Answer 10

└higher than average reading ability
└poor spatial, visual memory and mathematical skills
└socially immature

Question 11

Atypical sex chromosome patterns
strengths
summary

Answer 11

Contribution to nature-nurture debate

Practical application - Herlihy et al (2011)

Question 12

Atypical sex chromosome patterns
strengths
Contribution to nature-nurture debate

Answer 12

└studies of people with atypical sex chromosome patterns are useful
└as they contribute to our understanding of the nature-nurture debate
└can compare them to chromosome typical individuals
└identify psychological and behavioural differences
└e.g. people with Turners syndrome have higher verbal ability
└suggests innate nature influences powerful effect on psychology and behaviour

Question 13

Atypical sex chromosome patterns
strengths
Practical application

Answer 13

└continued research into atypical sex chromosome patterns is likely to lead to earlier and more accurate diagnoses of Turner’s/Klinefelter’s syndromes in the future
└Herlihy et al (2011)
└Australian study of 87 individuals with Klinefelter’s syndrome
└those who had been treated from a young age had significant benefits compated to those who had been diagnosed in adulthood
└=increeded awareness of these conditions may have practical application

Question 14

Atypical sex chromosome patterns
limitations
summary

Answer 14

Environmental explanations

Unusual sample

Question 15

Atypical sex chromosome patterns

limitations

Answer 15

└chromosome abnormalities and Turner’s/Klinefelter’s syndrome
└correlation does not mean causation
└may be environmental and social influences responsible for behavioural differences
└e.g. social immaturity of people with Turner’s syndrome may be as they are treated immaturely by people around them (due to pre-pubescent appearance)
└ =indirect impact on performance at school (=poor mathematical skills)
└=wrong to assume observed psychological and behaviour differences are due to nature

Question 16

Atypical sex chromosome patterns

limitations

Answer 16

└unusual sample
└unrepresentative
└can’t generalise to wider population
└individuals who look different are likely to be treated differently to peers
└=difficult to distinguish between nature and nurture