Sex-Linked Inheritance Problem Set

Problem 8: Tracing the inheritance of the human Y chromosome

Tutorial to help answer the question

Women have sex chromosomes of XX, and men have sex chromosomes of XY.
Which of a man's grandparents could not be the source of any of the genes on his Y-chromosome?

Tutorial

Y chromosome inheritance

The diagram shows how the X and Y chromosomes are inherited from the maternal and paternal grandparents to the parents to the son.
The Y chromosome is passed strictly from the father to male children in each generation.
Neither maternal grandparent nor the paternal grandmother can be a source of any genes on the Y chromsome.

The Biology Project
University of Arizona
Updated: July 15, 1999
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