[Solved] Why do some people have unusual chromosome combinations,such as XYY and XXX? A) Genetic disease causes a spontaneous increase in the number of sex chromosomes in mature gametes. B) Errors occurred in chromosome segregation during meiosis in their fathers or mothers. C) People who inherit large numbers of short tandem repeats (STRs)also inherit extra sex chromosomes. D) A mistake in mitosis during embryonic development leads to extra sex chromosomes in every cell. E) It is not known why these unusual chromosome combinations occur. Therapist's: Pertaining to a therapist, often relating to their methods, practices, or interventions used in the treatment of disorders. Cognitive-Behavioral: Referring to a type of psychotherapeutic treatment that helps patients understand the thoughts and feelings that influence behaviors. Object Relations: A theory in psychoanalysis that considers the importance of the relationships and emotional bonds between subjects and their significant others. Biological: Pertaining to the processes and phenomena of living organisms or to the application of these processes in both normal and pathological states.