which of the following is the main reason mimosa pudica shows movement even though it lacks a nervous system?

Mimosa pudica moves mainly because of rapid changes in turgor (water pressure) in special cells at the pulvinus, not because of a nervous system.

Quick Scoop

When you touch the leaves of Mimosa pudica (the “touch‑me‑not”), a mechanical stimulus triggers an electrical signal (action potential) that travels through the pulvinus, a small swollen joint at the base of the leaf or leaflet. This signal causes ions like potassium and chloride to move out of certain motor cells, water rapidly follows, those cells lose turgor and collapse slightly, and the leaflets fold and droop.

So in school‑level question terms, the “main reason” for its movement is:

• Rapid loss and redistribution of turgor pressure in pulvinar motor cells (turgor‑driven movement).

If the options include things like:

• “Presence of specialized motor cells in the pulvinus that undergo turgor changes”
  versus

• “Well‑developed nervous system”

• “Growth movement”

• “Muscular tissues”

then the correct choice is the one that mentions turgor changes in pulvinar motor cells or turgor changes in the pulvinus.

In short: Mimosa pudica moves because touch induces electrical signals that cause sudden turgor changes in pulvinus cells, making the leaf fold, even though it has no nerves.