Q. (a) Explain how auxins help in bending of plant stem towards light.?

Question

Answer

When a lot of light falls on one surface of plant and all auxin hormones move in shaded area where light isn't falling, it allow plant to grow toward the direction of light.

Thank you.. :-)

Answer

Auxin is a plant hormone it helps in growth of the plant part it is a growth promoter hormone
when a light falls on a plant part auxin gets deposited on the opposite of the sun rays
any as it is a growth promoter it makes cell enlargement on the opposite side which makes the plant to bend towards sun rays and show positive phototropism

Answer

Auxins hormones helps in cell elongation and hence due to phototropism auxins elongate cells in either side of plant which help in bending of plant or flower towards tge direction of light.

Answer

When light is coming from one side of the plant, Auxin diffuses towards the shady side of the shoot. This concentration of Auxin stimulates the cell to grow longer on the side of shoot which away from the light.

Answer

Introduction:
Auxins are plant hormones that play a crucial role in various aspects of plant growth and development. One of their important functions is phototropism, which is the bending of plant stems towards a light source. In this response, we will explain how auxins help in the bending of plant stems towards light in detail.

Key points:
- Phototropism is a vital mechanism that allows plants to optimize their exposure to light, which is essential for photosynthesis.
- The bending of plant stems towards light is a result of differential growth on the shaded and illuminated sides of the stem.
- Auxins, particularly the main auxin called indole-3-acetic acid (IAA), are responsible for this differential growth.

Explanation:
1. Perception of light:
- Photoreceptor proteins in plant cells, specifically in the shoot tips, are responsible for perceiving the direction and intensity of light.
- When light is perceived, a signal is transmitted to the cells in the shoot tip.

2. Redistribution of auxins:
- The perception of light triggers the redistribution of auxins in the shoot tip.
- Auxins are usually synthesized in the apical meristem, which is the growing tip of the stem.
- Light perception leads to the movement of auxins from the illuminated side to the shaded side of the stem.

3. Differential auxin concentration:
- The redistribution of auxins results in a higher concentration of auxins on the shaded side of the stem compared to the illuminated side.
- This difference in auxin concentration leads to differential growth between the two sides.

4. Cell elongation:
- Auxins promote cell elongation by loosening the cell wall, allowing the cells to expand.
- On the shaded side of the stem with higher auxin concentration, cell elongation is stimulated, leading to faster growth compared to the illuminated side.

5. Bending towards light:
- As a result of the differential growth, the stem bends towards the light source.
- The cells on the shaded side elongate more rapidly, causing the stem to curve towards the light.

Conclusion:
Auxins play a crucial role in the bending of plant stems towards light. They facilitate the differential growth of cells on the shaded and illuminated sides of the stem, causing the stem to curve and optimize its exposure to light. This phototropic response is essential for plants' ability to perform photosynthesis and grow towards favorable light conditions.

Similar Class 10 Doubts

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

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

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

Illustrate with the help of a diagram the effect of auxins in different parts of plant?

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

Related Content

About Class 10

Class 10 Study Material

Class 10 All Subjects

NCERT Textbook Solutions

Other Classes

Important Links

Company