role of chromosomes - biological approach

Question 1

what is the role of genes?

Answer 1

genes determine your biological sex
they instruct the production of various hormones, and these affect your sense/behaviour of maleness and femaleness i.e. your gender

Question 2

how many pairs of chromosomes does an individual have?

Answer 2

23 pairs in each cell of their body

Question 3

what do chromosomes carry?

Answer 3

hundreds of genes containing instructions about hormones, physical characteristics and behaviours

Question 4

what are one pair of chromosomes called?

Answer 4

the sex chromosomes because they determine such - SRY gene on Y chromosome confers male sexual characteristics

Question 5

what is there almost always a link between?

Answer 5

an individuals chromosomal sex (XX/XY) and their external genitalia (penis/vagina) and internal genitalia (ovaries/testes)

Question 6

what do all foetuses start off as? how do they develop?

Answer 6

start off with same external genitalia - female
3 months in, if the foetus is male it will then develop male genitalia due to the release of testosterone (due to the development of testes)

Question 7

atypical patterns of sex chromosomes - klinefelter’s syndrome

Answer 7

• due to an XXY configuration
• individual is born with a penis and develops as a fairly normal male
• approx. 1 in 1000 males have the condition
• such individuals tend to be taller than average and have less muscular coordination than average (low levels of muscle)
• physically look less masculine because of reduced levels of testosterone: less facial hair, broader hips, and possible breast tissue, often infertile

Question 8

atypical patterns of sex chromosomes - turner’s syndrome

Answer 8

• due to an XO configuration
• second sex chromosome is partly or completely missing
• approx. 1 in 2000 females
• born with vagina and womb
• characteristics include being shorter than average and having a lack of monthly periods
• wide range of symptoms: small lower jaw, narrow hips, miss-shaped internal organs

Question 9

what does intersex mean?

Answer 9

individual who is neither distinctly male nor female because of a mismatch between chromosomes and genitals
affects around 1% of the population

Question 10

david reimer case study

Answer 10

• identical twins (bruce and ryan) were circumsised at 6 months
• bruces operation was botched which meant he had to have his penis and testes removed
• they raised bruce as a girl, despite his biological sex being male
• david found out in his tee years about his true sex and decided to change and live as a man, he felt much better psychologically