What is the Difference Between Autonomic and Paratonic Movements?

The main difference between autonomic and paratonic movements lies in the stimuli that trigger them. Autonomic movements are spontaneous and take place due to internal stimuli, while paratonic movements occur due to external stimuli. Both types of movements are exhibited by plants and some unicellular organisms.

Autonomic movements:

• Also known as autotropism.
• Takes place spontaneously without any external stimuli.
• Occurs due to internal stimuli, especially due to the involvement of genes.
• Examples include growth and development, as well as movements related to gravity (geotropism) or light (phototropism).

Paratonic movements:

• Also known as tropic movements or tropisms.
• Occurs due to external stimuli such as light, gravity, water, or touch.
• Can be either positive (movement towards the stimulus) or negative (movement away from the stimulus).
• Examples include phototropism (growth towards light), geotropism (response to gravity), hydrotropism (response to water), and thigmotropism (response to touch).

In summary, autonomic movements are spontaneous responses to internal stimuli, while paratonic movements are induced responses to external stimuli. Both types of movements are essential for plant growth, development, and adaptation to their environment.

Comparative Table: Autonomic vs Paratonic Movements

The key difference between autonomic and paratonic movements lies in the stimuli that trigger them. Autonomic movements are responses to internal causes, such as genes, while paratonic movements are responses to external stimuli, such as heat, light, or touch. Here is a table comparing the two types of movements:

Autonomic movements are often spontaneous or automatic movements in plants that are not in response to external stimuli, while paratonic movements, also known as tropic movements or tropisms, are plant movements in response to external stimuli.