Pick out the correct statements:
(i) Hemophilia is a sex – linked recessive disease
(ii) Down’s syndrome is due to aneuploidy
(iii) Phenylketonuria is an autosomal recessive gene disorder
(iv) Sickle cell anaemia is an X-linked recessive gene disorder

The correct option is D (i), (ii) and (iii) are correct
Hemophilia is a sex – linked recessive disease that impairs the body's ability to make blood clots.
Down’s syndrome (trisomy 21) is caused due to aneuploidy.
Phenylketonuria is an autosomal recessive gene disorder.

Sickle-cell disease is caused by a gene mutation that leads to the production of sickle haemoglobin, which affects the function of the red blood cells in the body. This mutation is inherited from the parents of an individual in an autosomal recessive pattern.
Autosomal means that the mutation is not unique to the X or Y chromosome and can, therefore, affect males and female equally.
Recessive means that the mutation must be present in both the father and the mother in order for the child to get the sickle cell disease.