Explain the following phenomena .
a) Turner's Syndrome .
b) Down Syndrome .

Explanation

a) Turner.s Syndrome : The karyotype is `45` , X is due to monosomy `23` rd pair where one X-chromosome is last . A turner female does not show Barr bodies in her somatic cells . The symptoms are short stature, gonadal dysgenesis, webbed neck and broad shield like chest with widely spaced nipples .
b) Down syndrome : Down syndrome is a genetic condition that causes delays in physicals and intellectual development . The cause of this genetic disorder is the presence of an additional copy of the chromosome numbered `21` (Trisomy of `21`st set) . The Karyotype is designated as TRISOMY `21 (47, XX, +21)` . Characters are short statured, round head, furrowed tongue and partially opened mouth . Mental development and physical development is retarded .