The growth movements of plant parts in which the direction of the stimulus determines the direction of the response are known as tropic movements or tropism. Plants also have non-directional movements, which may not be growth-dependent. Name the movement which causes ‘X’ and ‘Y’ to grow downwards and upwards respectively. (1) Write the name of a hormone that plays a major role in falling of leaves. rapid cell division. (1) Leaves of the sensitive plant move very quickly in response to ‘touch’. How is this stimulus of touch communicated and explain how the movement takes place? (2)OR Name the plant hormone which is synthesized at the shoot tip. How does this hormone help the plant to bend towards light? (2)

I. II. Abscisic acid (ABA) Cytokini III. The leaves of Mimosa pudica fold in response to touch due to Thigmonastic (Seismonastic) Movement. The stimulus is communicated by an electrochemical signal, leading to changes in turgor pressure in specialized cells called pulvini. When touched, water moves out of pulvini cells, causing them to collapse, leading to the folding of leaves.OR Auxin is the hormone synthesized at the shoot tip. Auxin accumulates on the shaded side of the shoot. This promotes cell elongation on that side, causing the shoot to bend towards the light. This response is called Phototropism (Positive Phototropism in shoots).

X: Positive Geotropism (towards stimukus)Y: Negative Geotropism (away from stimulus) Abscisic acid Cytokinin When the leaves of sensitive plants are touched, the water pressure within specialized cells at the base of the leaves, known as pulvini, causes the leaves to fold upward due to a loss of turgor pressure. This process involves chemical signals that facilitate water migration out of the cells.OR Auxin is a plant hormone synthesized at the shoot apex. The inclination of plants toward light is known as phototropism. In the stem, the shaded side contains a higher concentration of auxin and exhibits increased elongation, resulting in the stem bending towards the light.

The growth movements of plant parts in which the direction of the stimulus determines the direction of the response is knwon as tropic movements or tropism. Plants also have non-directional - Science

प्रश्न

The growth movements of plant parts in which the direction of the stimulus determines the direction of the response are known as tropic movements or tropism. Plants also have non-directional movements, which may not be growth-dependent.

Name the movement which causes ‘X’ and ‘Y’ to grow downwards and upwards respectively. (1)
Write the name of a hormone that plays a major role in
1. falling of leaves.
2. rapid cell division. (1)
1. Leaves of the sensitive plant move very quickly in response to ‘touch’. How is this stimulus of touch communicated and explain how the movement takes place? (2)
  OR
2. Name the plant hormone which is synthesized at the shoot tip. How does this hormone help the plant to bend towards light? (2)

घटनेचा अभ्यास

उत्तर १

II.

Abscisic acid (ABA)
Cytokini

III.

- The leaves of Mimosa pudica fold in response to touch due to Thigmonastic (Seismonastic) Movement.
- The stimulus is communicated by an electrochemical signal, leading to changes in turgor pressure in specialized cells called pulvini.
- When touched, water moves out of pulvini cells, causing them to collapse, leading to the folding of leaves.
  OR
- Auxin is the hormone synthesized at the shoot tip.
- Auxin accumulates on the shaded side of the shoot. This promotes cell elongation on that side, causing the shoot to bend towards the light. This response is called Phototropism (Positive Phototropism in shoots).

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उत्तर २

X: Positive Geotropism (towards stimukus)
Y: Negative Geotropism (away from stimulus)
1. Abscisic acid
2. Cytokinin
1. When the leaves of sensitive plants are touched, the water pressure within specialized cells at the base of the leaves, known as pulvini, causes the leaves to fold upward due to a loss of turgor pressure. This process involves chemical signals that facilitate water migration out of the cells.
  OR
2. Auxin is a plant hormone synthesized at the shoot apex. The inclination of plants toward light is known as phototropism. In the stem, the shaded side contains a higher concentration of auxin and exhibits increased elongation, resulting in the stem bending towards the light.