6.2.2 Movement Due to Growth

Description

Quick Overview

This section explains how growth in plants results in movement, differentiating between movements due to growth and responsive movements.

Standard

Plants exhibit movements due to growth, such as the tendrils of climbing plants and the directional growth of shoots and roots. These movements help plants adapt to their environment, responding to stimuli like light, gravity, and water through phenomena known as tropisms.

Detailed

Detailed Summary

In this section, we explore how plants exhibit movement as a result of growth, primarily focusing on tropisms, which are directional movements towards or away from stimuli. An example includes the tendrils of climbing plants, which wrap around supports when they encounter them; this is due to differential growth where one side of the tendril grows faster than the other. Additionally, plants respond to light via phototropism, where shoots grow towards light, and to gravity via geotropism, where roots grow downwards. These adaptive movements ensure optimal exposure to sunlight and anchorage in the soil, thus enhancing the chances of survival. The section emphasizes that while some plant movements are quick, such as those seen in sensitive plants, growth-related movements tend to be slower and highlight the biological significance of hormone action in promoting this growth.

Key Concepts

  • Growth Movement: Movement in plants as a result of growth processes.

  • Tropisms: Directional movements in response to environmental changes.

  • Auxins: Key hormones facilitating growth and directional movement in plants.

Memory Aids

🎵 Rhymes Time

  • To grow towards the light, the shoot will sway, / Auxins promote growth in a sunny way.

📖 Fascinating Stories

  • Once upon a time, a little sunflower longed for the sun. Each morning it stretched and turned toward the light, seeking warmth and nourishment through its bending shoots.

🧠 Other Memory Gems

  • A-D-G: Auxins, Directional growth, Geotropism.

🎯 Super Acronyms

P-G = Plant Growth

  • Remember that photosynthesis guides how plants grow towards light.

Examples

  • The bending of sunflower stems towards sunlight (phototropism).

  • Roots growing down towards the gravitational pull (geotropism).

  • Tendrils of a pea plant wrapping around a fence for support.

Glossary of Terms

  • Term: Phototropism

    Definition:

    Directional growth of a plant shoot towards light.

  • Term: Geotropism

    Definition:

    Growth of plant roots downward in response to gravity.

  • Term: Tendril

    Definition:

    A specialized structure used by climbing plants to attach and support themselves.

  • Term: Auxin

    Definition:

    A plant hormone that promotes elongation of cells, facilitating growth towards light.

  • Term: Hormone

    Definition:

    A chemical substance produced in one part of an organism that influences growth and behavior in other parts.