Q.Which part of the plant is best suited for making virus-free plants and why?

In a plant infected with a virus, the virus particles spread through the plant mainly via its vascular tissue (phloem/xylem network) and, to some extent, through connections between neighbouring cells. However, the apical meristem — the actively dividing tissue at the very tip of a shoot (the shoot apex) — largely lacks a developed vascular system connecting it to the rest of the plant, and its cells divide very rapidly.

Because of this:

• The virus is unable to reach or multiply effectively in the outermost cells of the meristematic tip, since the route (vascular tissue) through which it usually spreads is absent or poorly developed there.
• Even if some virus particles are present, the very rapid cell division in the meristem means that new, virus-free cells are produced faster than the virus can multiply and spread into them, so the growing tip effectively stays ahead of the infection. …

Name the meristematic tip as the answer first, then give the two-part biological reasoning: absence of vascular tissue (the virus's usual route) and rapid cell division o …

• Naming a wrong plant part (e.g., leaf, root) instead of the shoot-tip/apical meristem.
• Giving the answer without the reasoning (lack of vascular connection + fast cell division), which is the actual biological explanation being asked for. …