Errors and Exceptions in Chromosomal Inheritance. Errors. Physical and chemical disturbances Errors during meiosis Plants are more tolerant of genetic defects than animals. Nondisjunction. Occurs when problems with meiotic spindle cause errors in daughter cells
Normal chromosome 9
Normal chromosome 22
Translocated chromosome 22
Figure 15.16Other translocations
Distinguish between sex-linked disorders and sex chromosome disorders.
The ABO blood type locus has been mapped on chromosome 9. A father who has blood type AB and a mother who has blood type O have a child with trisomy 9 and blood type A. Using this information, can you tell in which parent the nondisjunction occurred? Explain your answer.