Describe pedigree analysis and draw its symbols.

(N/A) Pedigree analysis is the study of the inheritance of a particular trait,abnormality,or disease in a family over several generations. It is represented as a family tree.
In human genetics,pedigree analysis is a powerful tool because controlled crosses,which are possible in organisms like pea plants,cannot be performed in humans due to reasons such as: $(i)$ The progeny produced is very small (usually one) and takes a long time to mature. $(ii)$ Controlled crosses are not ethically or practically possible.
The standard symbols used in pedigree analysis are as follows:
| Symbol | Meaning |
| :--- | :--- |
| Square | Male |
| Circle | Female |
| Diamond | Sex unspecified |
| Shaded symbols | Affected individuals |
| Square-Circle connected by horizontal line | Mating |
| Square-Circle connected by double horizontal line | Mating between relatives (consanguineous mating) |
| Parents connected by horizontal line with offspring below | Parents with children (in order of birth from left to right) |
| Parents with a shaded square below | Parents with an affected male child |
| Diamond with number $5$ inside | Five unaffected offspring |