How does phototropism occur in plants?

Name: Problem 6, Chapter 7: NCERT Class 10 Science
Uploaded: 2021-08-05T11:10:26-08:00
Duration: 3 min 21 s
Channel: Anitha Mary
Description: How does phototropism occur in plants?

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Key Concepts

Phototropism

Phototropism is a growth response in plants where the direction of growth is determined by the direction of light. This process enables plants to optimize their exposure to sunlight, which is crucial for photosynthesis and overall survival.

Auxin Distribution

Auxins are a class of plant hormones that play a central role in phototropism. When a plant is exposed to light, auxins redistribute unevenly, accumulating more on the side that receives less light. This uneven distribution causes cells on the shaded side to elongate more than those on the illuminated side.

Light Perception Mechanisms

Plants possess specialized photoreceptors that detect light intensity and direction, particularly blue light. These photoreceptors initiate a signal transduction cascade that results in the redistribution of hormones such as auxin, guiding the plant's growth towards the light source.

Differential Cell Elongation

The uneven distribution of auxin leads to differential cell elongation, where the cells on the side of the stem receiving less light expand more, causing the stem to bend towards the light. This mechanism is essential for adapting to varying light conditions and maintaining optimal growth.

Transcript

00:01 In this question, we are going to discuss about the phototrophysm in plants.

00:10 So what is this phototrophysm? it is a movement of plant towards light.

00:14 So the plant moves directionally response to light which is called as phototrophysm.

00:20 Plant is composed of two systems.

00:23 One is the shoot system and other one is the root system.

00:28 Shute system is the system which is above the soil of the plant.

00:33 And the root system as the plant passed which is under the soil so the shoot responds to bending towards a light and root response by bending away from light so shoot is so bending towards light towards light or the sunlight and root system where it bends away from the sunlight so there is a special hormone which is responsible for this phototrophism.

01:13 So this hormone is called as oxen.

01:20 The process is when sunlight falls straight on the plants.

01:23 The hormone oxen is synthesized at the stem tip.

01:28 And it spreads uniformly throughout the stem.

01:31 The equal distribution of this oxen helps the stem to grow straight.

01:37 So let's see how the plant grows in the presence of sunlight.

01:44 So this, the first plant is where the sunlight falls straight on the plant and the oxen's on the stem tip is equally distributed.

01:56 So straight sunlight is got...