Question

Explain the role of pedigree analysis in human genetics. Add a note on symbols used in pedigree analysis.

Hint:

Pedigree analysis helps detect inheritance patterns of traits. Remember: Square = male, Circle = female, shading = affected.

Answer 1

Role of Pedigree Analysis: Pedigree analysis is the study of inheritance of traits in humans using family records and ancestral lineage. It helps in: \[\begin{array}{rl} \bullet & \text{Tracing the inheritance pattern of specific traits or genetic disorders.} \\ \bullet & \text{Identifying whether a trait is dominant, recessive, autosomal, or sex-linked.} \\ \bullet & \text{Predicting the risk of genetic diseases in future generations.} \\ \bullet & \text{Assisting in genetic counseling and disease prevention.} \\ \end{array}\] Symbols used in Pedigree Analysis: \[\begin{array}{rl} \bullet & \text{\(\square\) = Male} \\ \bullet & \text{\(\bigcirc\) = Female} \\ \bullet & \text{\(\square\) or \(\bigcirc\) shaded = Affected individual} \\ \bullet & \text{Horizontal line between male and female = Mating} \\ \bullet & \text{Vertical line from parents = Offspring} \\ \bullet & \text{Roman numerals = Generations (I, II, III …)} \\ \end{array}\] Significance: Pedigree analysis is an essential tool in human genetics since controlled crosses cannot be performed as in plants/animals.