Why is pedigree analysis done in humans?

Why is pedigree analysis done in humans? List two reasons why the Mendelian experiments cannot be carried out in human beings.

(i) Pedigree analysis is carried out for studying inheritance of human traits. It is also useful when studying species with a long generation time.
(ii) The common Mendelian experiments are not possible in humans because
(a) Generation period is long.
(b) Progeny of a couple is small