How is the movement of leaves of the sensitive plant different from the movement of shoot towards light?

Question

Answer

Difference between the movement of leaves of the sensitive plant and movement of shoot towards light.

(i) Movement of leaves of the sensitive plant is not directional to the stimulus of touch. But the movement of shoot is directional towards light.

(ii) Movement of leaves (drooping down) of sensitive plant is due to change in the amount of water present in them. The movement of the shoot towards light is due to growth controlled by growth hormone called auxin.

Answer

Answer

**Movement of Leaves of the Sensitive Plant**

The sensitive plant, scientifically known as Mimosa pudica, is a fascinating plant that exhibits a unique movement of its leaves when touched or disturbed. This movement is often referred to as 'thigmonasty' or 'nyctinasty.' The leaves of the sensitive plant fold inward or droop when they are touched or exposed to certain stimuli. Let's explore how this movement differs from the movement of shoots towards light.

**1. Mechanism of Leaf Movement:**

The movement of leaves in the sensitive plant is a result of changes in the turgor pressure within specialized cells called pulvinus. The pulvini are located at the base of each leaflet and respond to external stimuli by rapidly losing turgidity. This loss of turgor pressure causes the leaflets to fold or droop, providing protection to the plant.

**2. Response to Touch:**

When the sensitive plant is touched, the pulvinus cells lose turgidity due to the activation of specific ion channels. This causes the leaflets to fold inward, making the plant appear wilted or droopy. This response to touch is an adaptive mechanism to deter herbivores and protect the plant from potential harm.

**3. Duration of Leaf Movement:**

The movement of the sensitive plant's leaves in response to touch is temporary and reversible. Once the stimulus is removed or after a certain period of time, the leaves gradually regain turgidity, and the leaflets unfold, resuming their original position.

**4. Movement of Shoots towards Light:**

In contrast to the temporary leaf movement of the sensitive plant, the movement of shoots towards light, known as phototropism, is a more extended and continuous process. Phototropism is a growth response in which plant shoots bend towards a light source, optimizing their exposure to sunlight for photosynthesis.

**5. Mechanism of Shoot Movement:**

Phototropism is primarily regulated by the plant hormone auxin, which accumulates on the shaded side of the shoot. This uneven distribution of auxin causes the cells on the shaded side to elongate, resulting in the bending of the shoot towards the light. The movement of shoots towards light is a process that occurs over an extended period, allowing the plant to maximize its access to sunlight for efficient photosynthesis.

**6. Duration of Shoot Movement:**

Unlike the temporary leaf movement in the sensitive plant, the movement of shoots towards light continues until the light source is no longer available or the plant reaches a suitable position for optimal light exposure. This movement is a growth response that enables the plant to adapt to its environment and ensure proper energy production through photosynthesis.

In conclusion, the movement of leaves in the sensitive plant is a temporary and reversible response to touch, while the movement of shoots towards light is a continuous growth response known as phototropism. Both these movements serve specific adaptive purposes in plants and are controlled by different mechanisms.

Similar Class 10 Doubts

How is the movement of the leaves of the sensitive plant different from the movement of a shoot towards light?

Which of the following is not a growth dependent response?

In twodifferent kinds of phototropic movement, shootsrespond by bending towards light while rootsrespond by bending away from it. How does this helpthe plant?

What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?

What is the difference between he manner in which movement takes place in a sensitive plant and the movement in our legs?

Top Courses for Class 10View all

Science Class 10

Social Studies (SST) Class 10

Mathematics (Maths) Class 10

English Grammar Advanced

English Grammar Basic

Top Courses for Class 10

Top Courses for Class 10

Suggested Free Tests

Related Content

About Class 10

Class 10 Study Material

Class 10 All Subjects

NCERT Textbook Solutions

Other Classes

Important Links

Company