AQA A Level Psychology
Gender - Role of Chromosomes
Notes
Paper Reference - 7182/3
● Within cells, we contain genetic material in the form of DNA (deoxyribonucleic acid).
This is responsible for our growth and development. These are wound around
histone proteins to form chromosomes.
● Each somatic cell contains 46 chromosomes, 23 pairs.
● There are 22 pairs of autosomes and 1 pair of sex chromosomes. The sex
chromosomes can either be X or Y.
● Female sex chromosome pattern - XX.
● Male sex chromosome pattern - XY.
● On the Y chromosome, there is a gene called the SRY gene. This is responsible for
sex determination. Up to 8 weeks, all foetus’s are ‘identical’ as they develop internal
sex organs. At 8 weeks, if the SRY gene is present, testosterone is produced which
leads to the development of the external sex organs and halting of internal sex organ
development.
Gender - Role of Chromosomes
Notes
Paper Reference - 7182/3
● Within cells, we contain genetic material in the form of DNA (deoxyribonucleic acid).
This is responsible for our growth and development. These are wound around
histone proteins to form chromosomes.
● Each somatic cell contains 46 chromosomes, 23 pairs.
● There are 22 pairs of autosomes and 1 pair of sex chromosomes. The sex
chromosomes can either be X or Y.
● Female sex chromosome pattern - XX.
● Male sex chromosome pattern - XY.
● On the Y chromosome, there is a gene called the SRY gene. This is responsible for
sex determination. Up to 8 weeks, all foetus’s are ‘identical’ as they develop internal
sex organs. At 8 weeks, if the SRY gene is present, testosterone is produced which
leads to the development of the external sex organs and halting of internal sex organ
development.
