Question

Three Mark Questions :
(a) Name the kind of diseases/disorders that are likely to occur in human if,
(i) There's a mutation in the gene that codes for an enzyme phenylalanine hydrolase.
(ii) There is an extra copy of chromosome 21.
(iii) The karyotype is XXY.
(b) Mention any one symptom of the diseases/disorders named above.

Answer 1

a) (i) Phenylketonuria (ii) Down's syndrome (iii) Klinefelter's syndrome

b) In Klinefelter's syndrome, the males start developing feminine characters (such as the development of breast). Such individuals are sterile.