Pedigree Analysis ||Class 12 Biology

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     Pedigree analysis is an analysis of traits in several generations of a family. In this analysis, the inheritance of a particular trait is represented in the family tree over generations. 
       Importance of pedigree analysis are as follows: 
1. It is used to know the possibility of expressive or recessive allele which may cause genetic disorders.
2. It shows the origin of trait and flow of that trait in a family.
3. It predicts the harmful effects of marriage between close relatives.
4. It is extensively used in medical research.


      Pedigrees use a standardized set of symbols, squares represent males and circle represent females. It the sex of the person is unknown a diamond is used as symbol. Affected individuals is represented by a filled in (darker symbol). Heterozygotes, when identifiable, are indicated by a shade dot inside a symbol or a half filled symbol. Relationships in pedigree are shown as a series of lines. Parents are connected by a horizontal line and a vertical line leads to their offspring. The offspring are connected by a horizontal sibship (all the siblings of a family) line and are listed in birth order from left to right. If the offspring are twins they will be connected by a triangle. Each generation is identified by a Roman numeral (I, II, III, IV and so on).


Location: India

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