Structures and their Functions in Plants

Key Concepts

• Plants and their importance
• Different parts of plants
• Vascular and nonvascular plants
• Roots and root system
• Structure and functions of stem
• Structure and functions of leaf

Introduction: 

We know that plants are living things. They do so much more than just add beauty to our surroundings. 

Plants provide us with the food that we eat and also some of the clothes we wear. They even give off a gas called oxygen that we breathe. 

Earth would be a barren place without plants. Because of plants, our planet is full of life. 

Plants come in a variety of sizes, shapes, and colors. Some are so small we can barely see them. Others can be as tall as skyscrapers.  

On Earth, the giant California redwoods are the tallest living things. Some are even 112 meters (367 feet) tall. That means it is taller than the Statue of Liberty! 

Explanation: 

In all, there are around 400,000 different types of plants. Each one is unique. Yet, most plants share some common parts.  

Plants have different parts, like roots, stems, leaves, flowers, and fruit. These structures help them survive. 

These parts act like different components of a system that help the plant to perform various functions required for its growth, reproduction, behavior and survival. 

We know that plants are classified as shrubs, bushes, trees, etc., but plants are also divided into two types vascular and non-vascular plants. 

Plants that do not have proper root, stem and leaves are called vascular plants. 

Non-vascular plants are small plants that grow close to the ground and act like sponges, soaking up water and minerals. Mosses are an example of non-vascular plants. Some parts of non-vascular plants resemble the structures of vascular plants, but their functions are different. 

For example, non-vascular plants have structures that resemble roots, but these parts do not absorb water. Instead, they help anchor the non-vascular plant to the ground. These plants either lack stems or leaves. In place of stems or leaves, they have a stalk on which leaflike structures grow. 

The majority of plants we see on a daily basis are vascular plants. Water and nutrients are transported in vascular plants by a system of tubes. These tubes run through the roots, stems, and leaves of the plant. The roots help to absorb the nutrients and water and anchor the plant in the ground. The stem of a plant has leaves attached to it.  These leaves help the plant prepare its food. 

All flowering plants, such as rosebushes and magnolia trees, are vascular plants. Flowers are reproductive structures, although they are not found on all vascular plants. Cones are reproductive structures produced by some vascular plants, such as pine trees. 

Roots: 

Plants require roots and stems to take in and transport the materials they require to survive and grow. A plant’s root system is commonly found below ground.  

In most cases, you won’t be able to see it. Roots keep the plant stable in the ground. Roots store food made by the plant’s leaves like in carrots, radishes, beetroot, etc. 

Roots also absorb water and materials called minerals from the soil. The plants get nutrients from the water and minerals present in the soil.  

A nutrient is any material required by living things for energy, growth, and repair. Plants also need nutrients to live and grow. 

Types of roots: 

Although all roots perform the same functions, different plants have different types of roots. 

There are two main types of roots—fibrous roots and taproots. 

Many plants have one large root called a taproot. Taproots are thick, strong roots that grow deep in the soil. They grow deep into the soil toward Earth’s center due to gravity. Taproots take in water and nutrients from the soil. They also store food made by the plant. Carrots are examples of taproot system. 

 

In some plants, like grass and pine trees, the roots spread out in various directions. This type of root is called a fibrous root system.  

Fibrous roots are thin, branching roots that grow close to the surface. Fibrous roots of the same plant are all about the same size. They grow longer than taproots. Fibrous roots also grow close to the surface to take in water after it rains. Grasses and most trees have fibrous roots. 

Stem: 

Stems are structures that support the leaves, flowers, and fruits of plants. 

Stems often grow up towards the light, plants’ primary source of energy. Most plant stems have small tubes that move water, sugar and minerals from the roots to the leaves. At the same time, food prepared in the leaves is transported from the leaves to the stems and roots via other tubes. 

Some plants store the food that they produce in their stems, like sugar cane or asparagus. 

Most plant stems grow above ground, but some plants have stems that remain underground. 

Some stems are thin and grow along the surface of the ground. The stem of a pumpkin is able to grow roots and a new plant. Other stems, called vines, grow parts that wrap around objects that support the plant. 

a)Herbaceous

b) Woody 

    Trees and Shrubs 

 

Stems come in a variety of shapes, sizes, and colors. 

Woody stems are thick, rigid and non-flexible. Some plants, such as trees, have a single, hard, woody stem called a trunk. Shrubs have numerous smaller, woody stems. Trees and shrubs live for more than one growing season. 

Some stems are herbaceous. They are green in color, soft and flexible. 

Green stems are often found in smaller plants such as daisies. Many plants with soft stems sprout, grow and die all in one season. 

Leaves:  

Leaves are the structure of a plant that uses sunlight to produce sugar for the plant’s food. 

Leaves come in various shapes and sizes. They can be round, heart-shaped, or triangular. They can also be long, short, wide, or narrow.  

Different types of leaves have different textures. Some plant leaves have small hairs that make them feel fuzzy. These hairs help the plant from drying out and protect it from animals. Other plants have leaves which are smooth and waxy. This waxy coating helps the plant from drying out. 

Leaves also have veins. These veins are tiny tubes that help carry food made by the leaves to the plant’s flowers, stems, and roots. 

Veins also help to carry water and minerals through the leaves. 

When the veins are filled with water, they even help support the leaves. 

Leaves make their own food by the process of photosynthesis. During photosynthesis, plants use sunlight, water, and a gas in the air called carbon dioxide. Plants use these materials to make sugar, which is a source of food and energy for plants. 

Some plants utilize their leaves to store water like in cactus or food like in spinach or lettuce. Leaves have small openings known as stomata, underneath it, that allows the plant to get rid of extra water as part of the process of transpiration.

Summary

• Plants provide us with the food that we eat and also some of the clothes we wear. They release a gas called oxygen, which we breathe.
• Plants come in a variety of sizes, shapes, and colors. There is various type of plants found on earth which differ in their structures.
• However, there are some basic parts that are shared by most plants.
• These parts act like different components of a system that help the plant to perform
• various functions required for its growth, reproduction, behavior and survival. Plants require roots to take in and transport the materials they require to survive and grow.
• A plant’s root system is commonly found below ground. Roots are covered with root hairs. Roots help absorb water and minerals from the soll.
• There are two main types of roots-fibrous roots and taproots.
• Fibrous roots are thin, branching roots that grow close to the surface to take in water
• after it rains. • Taproots are thick, strong roots that grow deep in the soll.
• Stems are structures that support the leaves, flowers, and fruits of plants.
• Stems are of two types – woody and herbaceous.
• Stems carry nutrients and water from roots to the other parts of the plant. They transport food from leaves to other parts of plant.
• Some stems can store food.
• Leaves are the structure of a plant that uses sunlight to produce sugar for the plant’s food Some plants use leaves to store water or food.
• Most leaves have veins which are like tiny pipes that carry water, nutrients and food.