CBSE Class 12-science Answered

2. Criss cross inheritance:

• It is the transmission of a gene from mother to son or father to daughter. Those patterns of inheritance are called crisscross inheritance or skip generation inheritance, in which a character is inherited to the second generation through the carrier of first generation.
• The sex linked characters exhibit criss-cross inheritance.
• Genes on X chromosome but not on Y chromosome leads to a “criss-cross” pattern of inheritance where sons receive their X chromosome from the maternal parent and daughters receive an X from both parents.
• There are several, well-known sex-linked traits in humans: examples include hemophilia, color blindness, and the fragile X syndrome which follow criss cross pattern of inheritance.