Modification of root, stem and leaf | Macmillan Education India

Summary

This educational script delves into the fascinating world of plant modifications, detailing how roots and shoots adapt for various functions beyond their primary roles. It explains how roots can be modified for storage, support, respiration, and absorption, while stems may store food or provide additional support through structures like tendrils and stolons. The script also highlights unique leaf adaptations for food storage, support, and protection, including the specialized functions of carnivorous plants. The engaging narrative is designed to spark curiosity about the diverse ways plants evolve to thrive in their environments.

Takeaways

• 🌱 The part of the plant that grows above the soil after germination is called the shoot system, which includes branches, leaves, flowers, and fruits.
• 🌿 The root system grows underground and has two primary functions: fixation and absorption of nutrients and water from the soil.
• 🔄 Roots can be modified to perform additional functions such as storage, additional support, respiration, and additional absorption.
• 🥔 Examples of modified roots include tuberous roots for food storage, prop roots for support, stilt roots for mechanical support, and pneumatophores for respiration in marshy conditions.
• 🌳 The shoot system's stem is primarily responsible for transporting fluids and nutrients and providing support to the plant.
• 🌵 Modified stems can store food, like in the case of the cactus, which has a thick green stem that holds water for survival in arid conditions.
• 🌿 Stems can also be modified into tendrils that coil around supports to help the plant climb, as seen in passionflower and pumpkin plants.
• 🌷 The primary function of leaves is photosynthesis, but they can also be modified to serve other purposes such as food storage, support, and defense.
• 🌿 Modified leaves can become tendrils for support, spines for defense against herbivores, or large flat structures to help plants float on water, like in water lilies.
• 🌵 Cacti have modified leaves into spines to reduce water loss, adapting to desert environments.
• 🌮 Carnivorous plants like the Venus flytrap and pitcher plant have modified leaves to trap and digest insects for nutrition.

Q & A

What are the two primary functions of roots in a plant?

The two primary functions of roots are fixation, which anchors the plant to the ground, and absorption, which allows the roots to take in nutrients and water from the soil necessary for plant growth.

What are the four main additional functions that roots can be modified to perform?

Roots can be modified to perform four main additional functions: storage of food, additional support, respiration, and additional absorption.

What is the term for the swollen roots of some plants that store excess food?

The swollen roots that store excess food are called tuberous roots.

How do aerial roots in banyan trees provide additional support to the plant?

Aerial roots in banyan trees hang vertically from the branches and act like pillars when they reach the ground, providing additional support to the tree.

What is the function of stilt roots in the Indian crew pine or pandanus plant?

Stilt roots in the Indian crew pine or pandanus plant develop obliquely downwards and act like stilts, providing mechanical support to the plant.

What is the purpose of pneumatophores in certain trees growing in marshy places?

Pneumatophores are modified roots that grow upward to help trees in marshy places respire, as they cannot get enough oxygen from the soil.

What is the role of the feeder roots in the money plant?

Feeder roots in the money plant are long and slender, helping the plant absorb additional nutrients and water from the soil, which contributes to its rapid growth.

What are the primary functions of a stem in a plant?

The primary functions of a stem are the transportation of fluids and nutrients to different parts of the plant and providing support.

How are stems modified to store food in some plants?

In some plants, stems are modified to store food underground, such as in tubers, bulbs, and rhizomes, which can be roughly spherical, conical, or grow horizontally under the soil, respectively.

What is the function of tendrils in plants like the passionflower and pumpkin?

Tendrils in plants like the passionflower and pumpkin are modified stems that coil around a support to help the plant climb, providing additional structural support.

How are leaves modified in carnivorous plants to trap and digest small animals?

In carnivorous plants like the Venus flytrap and the pitcher plant, leaves are modified to form traps that capture and digest small animals, providing the plant with additional nutrients.