What is pedigree analysis? Suggest how such an analysis can be useful?

Pedigree analysis is the study of transmission of particular traits over the generations for finding out the possibility of their occurrence in the future generations.
Importance of pedigree analysis is as follows:
(i) It is used to know the possibility of expressive or recessive allele, which may cause genetic disorders.
(ii) It shows the origin of trait and inheritance pattern of that trait in a family.
(iii) It predicts the harmful effects of marriage between close relatives. .
(iv) It is extensively used in medical research.