Question

Albinism and phenylketonuria are disorders due to
(A) Recessive autosomal genes
(B) Dominant autosomal genes
(C) Dominant sex genes
(D) Recessive sex genes

Answer 1

Hint: Genetic disorders occur due to the mutation or changes in the gene of the organism that transfer from one organism to the other organism. These are classified into a single gene, chromosomal and the complex genetic disorders. Albinism and the phenylketonuria are the inherited disorders.

Complete Answer:
(1) Albinism:
Albinism is the genetic disease that occurs due to the very little or absence of the melanin in the skin. It mainly occurs due to the mutations or changes in the gene that encodes the tyrosinase. The melanin is the coloring pigment present in the skins, hair and eyes. The symptoms of the disease are pale white or pinkish skin in the body and the white hairs even at the childhood age. And these people are sensitive to sunlight.

(2) Phenylketonuria:
It is also an inherited disorder that is mainly due to the decrease in the metabolism of the amino acid. It is characterized by the mutation in the gene for the phenylalanine hydrogenase enzyme. If this disease remains untreated, it may lead to many diseases like mental disorder, behavioral problems, lighter thin skin, small head, heart problems and intellectual disability. These are of two types as classic and variant. This can be avoided by eating the foods with the diet of low phenylalanine.
Hence these disorders are mainly due to the recessive autosomal genes.

Thus, the option (A) is correct.

Note: There is no curable treatment for the phenylketonuria. But if the child has this disorder the healthy normal brain can be controlled with the less phenylketonuria diet. And albinism is also not curable. The glasses or the contact lenses protect the albinism people from the exposure to sunlight.