Which of the following methods is most suited to assess function of a gene:

D i.e. Transgenic animals Mutations that completely disrupt the function of a geneQ are called knock out mutation. And the techniques for disrupting or knocking out of a specific gene in a specific cell, tissue or organ is called conditional /directed knock outs or targeted gene disruption (ablation). Transgenic animals can be produced by micro injecting one or few cloned genes into the nuclei of feilized egg (ovum)Q. If the new gene becomes successfully integrated into a chromosome, it will be present in the germline of few animals. By careful breeding homozygous transgenic line can be established. Although Southern /Nohern blot tests can assess changes in DNA /RNA and suggest a function of gene but it is necessary to conduct a specific genetic analysis in genetically modified animals to correctly define gene function. Many of gene knock outs do not have an apperent phenotype, either because of redundant functions of other genes or because the phenotype is subtleQ. Whereas homozygous transgenic animals (homozygous for new gene or genes) cause many features of disorder.