Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 7

Down Syndrome Revisited. About 5% of individuals with Down syndrome (see Human Connections, page 756)have a chromosomal translocation in which a thud copy of chromosome 21 is attached to chromosome 14. Such individuals receive this chromosome from one of their parents due to a malformation in a gonadal cell. What is the ploidy of such individuals with Down syndrome Why does receiving the modified chromosome from one of their parents lead to Down syndrome in such children