Explanation

A-Male, B-Female, C-Sex unspecified. The study of inheritance of genetic traits in several generations of a human family in the form of a family tree diagram is called pedigree analysis. Advantages (i) It helps in genetic counselling to avoid disorders (ii) It shows the origin of a trait and flow of a trait in a family (iii) It is important to know the possibility of a recessive allele that can cause genetic disorders like colour blindness, haemophilia, etc. Signosed in the pedigree are