Q.Transgenic animals are those which have a) Foreign DNA in some of their cells b) Foreign DNA in all their cells c) Foreign RNA in some of their cells d) Foreign RNA in all their cells

Step 1. Recall that transgenic animals are produced by introducing the transgene at a very early stage — typically into a fertilised egg or early embryo — before the organism's cells have begun to differentiate and multiply into the full-grown animal. Step 2. Because the foreign DNA is incorporated before this widespread cell division, it is copied into essentially every cell lineage as the embryo develops, meaning a genuine transgenic animal carries the foreign DNA in all of its cells, not just a subset. Step 3. Rule out the RNA-based options — transgenesis specifically introduces foreign DNA into the genome (a heritable change), not foreign RNA, which would not be stably inherited from cell to cell in the same way. Step 4. Rule out 'some of their cells' — that would describe a genetic mosaic or a somatic gene-therapy patient (as …

Distinguish germline-level transgenesis (foreign DNA in every cell) from somatic gene therapy (foreign DNA in only the …

• Confusing transgenic animals (whole-genome, every-cell modification) with somatic gene therapy patients (only specific treated cells carry the change). …