Principles Of Inheritance And Variation

Both Statement I and Statement II are correct.

Statement I: Phenylketonuria (PKU) is an example of Pleiotropy. Pleiotropy refers to a single gene influencing multiple phenotypic traits. In the case of PKU, a mutation in the gene responsible for producing the enzyme phenylalanine hydroxylase (PAH) leads to various phenotypic effects beyond the inability to metabolize phenylalanine.

Statement II: Affected individuals lack an enzyme that converts phenylalanine into tyrosine. This statement accurately describes the underlying cause of PKU. Due to the absence or dysfunction of phenylalanine hydroxylase, individuals with PKU cannot convert phenylalanine into tyrosine, leading to an accumulation of phenylalanine in the body.

Therefore, both Statement I and Statement II are correct.

The correct answer is: (B) and (D) only.

A new breed of sheep can be developed through various methods, but the most common and appropriate option among the given choices is "Cross breeding.

To prove the theory of mutation, Hugo de Vries used the plant Oenothera Lamarckiana, also known as the Evening Primrose.

Hugo de Vries conducted extensive studies on Oenothera Lamarckiana and observed sudden and heritable variations in its traits, which he attributed to mutations. These findings played a significant role in supporting the theory of mutation as a mechanism for evolution and genetic variation.