Question

Shock movement of leaves of sensitive plants, Mimosa pudica are
A) Thermonaty
B) Seismonasty
C) Hydrotropism
D) Chemonasty

Answer 1

Hint: Mimosa pudica is a sensitive plant characterised as a perennial flowering plant or creeping annual plant belonging to the Family Fabaceae.

Complete Answer:
Option a: Thermonasty is defined as a non-directional response produced by the plants when it is subjected to altering temperature conditions. Thus, this is the incorrect option.
Option b: Seismonasty or thigmonasty is defined as a nastic response produced either by plants or fungus as and when they are touched or sense a feel of vibration. Mimosa pudica are popular for their leaf movements i.e. gradual opening and closing of leaves according to the position of petioles. This is often acknowledged as the rhythmic movement of the plant often associated with the alteration of the day and night cycle of the environment. Thus, this is the correct option.
Option c: Hydrotropism is defined as a response generated by the plants wherein the plant growth is determined in terms of its directional growth. This directional growth is brought either by water concentration gradient or a stimulus. Thus, this is the incorrect option.
Option d: This is a nastic response produced by the plants in response to the presence of either the chemicals or the nutrients. Thus, this is the incorrect option.

Therefore, the correct option is b) Seismography.

Note: Seismonasty is also defined as a shock movement that is a characteristic feature of the Mimosa pudica plant. Other plants which have similar response are,
- Venus fly trap
- Dionaea