PSYC 100 Lecture Notes - Lecture 14: Inner Cell Mass, Sex Organ, Secondary Sex Characteristic

• School: Queen's University
• Department: Psychology
• Course: PSYC 100
• Professor: Caroline F Pukall

Document Summary

Human cells typically contain 23 pairs of chromosomes (chromosomes house dna) One pair of the 23 is the sex chromosome pair. An egg donates an x chromosome to the sex chromosome pair, and the sperm donates either an. Female = xx, male = xy (although other constellations exist as well. Reproductive organs (that produce reproductive cells, the gonads: testes and ovaries) Before the 7th week of gestation, the fetus has no gonads. Only possesses chromosomal sex at this point, so the internal structures have not yet developed. Around the 7th week of gestation a gene from the y chromosome, if present, called sry, triggers other genes to create proteins that develop into testes. If there is no y chromosome by the 9th week of gestation, then sry does not get activated (since it is not present) and ovaries develop. Both male and female bodies manufacture estrogen and testosterone.