Women have sex chromosomes xx, and men have sex chromosomes xy. which of a woman's grandparents could not be the source of any of the genes on either of her x chromosomes?

mother's father

father's mother

mother's mother

father's father

Classify the structures as homologous or analogous, depending on their structure and function.

Identify the various levels of atmosphere. troposphere mesosphere exosphere stratosphere thermosphere

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures