ANT100Y1 Lecture Notes - Lecture 7: Herd Immunity, Y Chromosome, Ossification

• School: UTSG
• Department: Anthropology
• Course: ANT100Y1
• Professor: Shawn Lehman

Document Summary

Biological sex is a unction of anatomy. Xy: male, xx female, trisomy (xxx, xxy, xyy), pentasomy (xxxx, Accepted viable explanation of sexuality is a continuum--not a simple anatomical thing. Fairly straightforward in humans; more variable in plants and animals. Unisex species: only girls , reproducing through parthenogenesis (non-sperm reproduction) Sequential hermaphroditism: individual chanes sex at some point in its life (male to female, female to hermaphrodite) Develop into males first, and when they mature, they become females; if dominant female is removed from group, largest and most dominant male becomes a female. Half of spermatozoons carry x chromosomes, other half carry y. A single gene (sry: sex-determining region y) present on y chromosome acts as a signal to set developmental pathway towards maleness. Males are homogametic (zz), while females are heterogametic (zw) Only one sex chromosome, referred to as x. Males only have one x chromosome (x0) while females have two (xx)