Physical DNA delivery — The microprojectile (gene gun) method introduces DNA into plant cells by what means?

Introduction / Context:
Biolistics, also known as the microprojectile method or gene gun, is a widely used physical technique for plant transformation, especially when cell walls or species traits make Agrobacterium methods inefficient. Understanding the principle clarifies when and why to choose this method.

Given Data / Assumptions:

• DNA can be precipitated onto dense microcarriers (gold or tungsten).
• High-velocity acceleration enables particles to cross cell walls and membranes.
• Delivery can target many cells or tissues simultaneously.

Concept / Approach:
In biolistics, DNA-coated particles are accelerated using pressurized helium, gunpowder charges, or spring-driven devices. The particles penetrate tissues, releasing DNA inside cells where it can integrate or be transiently expressed. This is fundamentally a ballistic (kinetic) delivery mechanism rather than micromanipulation with needles or electric field–mediated pore formation.

Step-by-Step Solution:

Verification / Alternative check:
Fluorescent reporter assays (e.g., GUS, GFP) show rapid transient expression post-bombardment, confirming ballistic entry.

Why Other Options Are Wrong:

• Micromanipulator/needles: describe microinjection, not biolistics, and are low-throughput.
• Electroporation of intact leaves without particles is a different technique and less common for whole tissues.
• “Any of the above” conflates distinct methods.

Common Pitfalls:
Using the term “bolistics” colloquially; the standard term is “ballistics/biolistics,” but the concept is the same: kinetic delivery with microprojectiles.

Final Answer:
with the help of bolistics