Exercises marked with (*) require further reading/search beyond the suggested texts.
4. (*) The figure below shows chromatograms for the same region of the X chromosome of a mother, a father, and their male child, not necessarily in this order. Which chromatograms could of the mother? And of the child?
Answer:
We know that the mother is the only person among them with two X chromosomes, so the last graph must be hers (since we can see two signals, for bases G and A, in the 8th base position). As for the child, his graph could be either the first or the second. It is impossible to tell from the given information.
© 2015 Joao Meidanis