Parts of Plants and Their Functions

The plants make the environment on this planet. They are an essential part of our lives. They lead human life and vegetation across the globe. There is a reason why the schools taught us biology in class 8th. Because it is important to know the prominence of plants in our lives.

The plants are autotrophs. They make their own food by photosynthesis. They intake carbon dioxide and release oxygen. They ensure purification in their surroundings and proper respiration for organisms around them.

There are different parts of plants which have their own feature and functions to do. They all hold an important place in the ecosystem and for healthy surroundings. The primary parts of the plant are – Roots, Stem, and Leaves. They are present in all types of plants.

And the secondary parts are – flowers and fruits which are not present in every plant. The parts differ from plant to plant as they all are scattered in different regions and conditions. Let’s take a look at those parts and their functions in detail.

Roots

The roots are the most important part of a plant. They are underground and together form a root system of a plant. They are responsible for holding the plant with the soil.

They act like an anchor on which the plant holds on to remain stable. They also regulate the plant’s health by absorbing nutrients, minerals, and water from the soil. These in turn help a plant grow. They also store food materials for the future.

The peak of the root has a root cap to protect them. The embryo once developed grows into radicals and forms the primary roots of the plant.

It also consists of lateral roots or the secondary/tertiary roots. The monocots are an exception here. Their primary roots grow into a large number of roots because the primary one is short-lived.

Sometimes roots also grow upwards to get oxygen for better respiration, called pneumatophores. Some other reasons for roots modification are – For Food Storage, For better Respiration, Nodulated Roots, and For Support.

Types of Roots

1. Tap root system – In dicotyledon plants, the radicle forms the primary roots which stay inside the soil. The lateral roots are secondary and tertiary. An example is a mustard.
2. Fibrous root system – The original roots live for a short time and a large number of roots replaces it over time. The roots begin from the stem base. An example is a wheat.
3. Adventitious Roots – In this case, The roots grow from the plant and are not radical. An example is the banyan tree. The hanging like the structure of this tree is the prop root. And in the case of sugarcane, the roots support from the stem base and are stilt root.
4. Pneumatophores Roots – In this case, the roots come out of the soil for better respiration. An example is Rhizophora, as they grow in swampy areas.

Stem

It is the second most important part of the plant after roots. It is above the ground and is green at a younger phase but turns brown as it grows. They support the shoot system of a plant and consist of leaves, fruits, and flowers.

The part where the leaves grow is a node and space between two nodes is an internode. They stand vertical on the ground and arise from plumule.

At a younger phase, they are weak but grow the strongest over time. They become the trunk and have a thick outer layer called bark. We can say that the stem supports the plant structure and later the tree.

Apart from supporting, they help in vegetative propagation. Potato and ginger have modified stems to store food.

It has various features that are essential for plants. The primary one is to support the framework and structure of the plant. This includes holding buds, flowers, leaves, and fruits. It maintains the strength of the plant by keeping it straight.

Another function is to act as a channel of transportation for water and minerals from roots to different parts of the plant. It also acts as a storeroom where the starch is stored.

An exception here is opuntia, which lives in desert areas. Its stems get thick with time to prevent water loss due to transpiration. Another function of the stem is to reproduce by vegetative propagation. This allows bearing flowers and fruits.

It is an asexual method of reproduction. It protects the xylem and phloem and allows their smooth functioning. The stem modification takes place in Potato, Ginger, and Turmeric.

Leaves

Leaves are again an important part of the plants. They are home to chlorophyll which is responsible for the production of food for plants. It uses sunlight, carbon dioxide, and water to prepare the food. A leaf further has three primary divisions – petiole, leaf base, and lamina.

The petiole keeps the leaf cool by exposing it to the wind. The leaf base is the extended part of the leaf. And the lamina has veins to transport minerals and provide rigidity to the leaf. There are mainly two types of leaves.

They are Simple Leaf and Compound Leaf. when the petiole connects the lamina to the main stem, it becomes a simple leaf. But a compound leaf is made of two leaflets.

The main function of the leaf is to carry out the process of photosynthesis. It prepares the food by using water and Co2 in presence of sunlight. Another important function is to remove excess water from plants called transpiration. It is done through small pores present on the surface called stomata.

They also store nutrients and water produced during photosynthesis. A succulent is an example of this function. Lastly, some plants use them for reproduction as well. An example is Bryophyllum. Leaves may modify to perform other functions as well as functions.

In order to defend the plants, they become tendrils to climb spines. This is common in cacti. The leaves of plants like onion and garlic often have to store food. And most of the insectivorous plants have modified leaves.

Leaf Venation and Transpiration

The pavement of veins and the veinlets in the lamina is leaf venation. Reticulate is when veinlets create a network. The ventilation is parallel when the veins run parallel to each other, this is common in monocotyledons. And most of the dicotyledonous plants have reticulate venation.

The plants absorb water from the soil but do not utilize all of it. This water usually evaporates through stomata and this process is transpiration. This creates a suction pull which allows water to reach heights of the plants.

This water absorption increases in the shade, dim light, under the fan, and inside poly bad. This is because of the transpiration rate increases in windy environments.

The plants are capable of taking in oxygen and releasing co2 and roots can respire too. And photosynthesis takes place during the day and the night. And for some organisms oxygen is poisonous and WBC uses it to kill bacteria.

Flowers

The flowers are not present in all the plants. They are colorful and serene to look at. They are the reproducing body of the plant. It has four primary parts – Petals, Sepals, Stamens, and Pistil. The petals are a colorful part and attract insects.

The sepals are the green leafy looking part under the petals which protects the bud. Then the stamens are the male reproductive part and have anther and filament. The androecium has the stamen. And a sterile stamen is staminode.

While the pistil is the female reproductive part and has stigma, style, and ovary. The pistil is a part of Gynoecium. The arrangement of ovules is Placentation. It follows the sexual reproduction process. It can be bisexual too. The arrangement of sepal and petals is aestivation.

Fruits

The flowering plants are responsible for bearing fruits. The mature ovary develops into a fruit after fertilization. First, they become and seed then a fruit. The fruits which do not go through fertilization are parthenocarpic and the process is Parthenocarpy.

Transportation in Plants

The complex tissues are most important as they are responsible for the transportation system in the plant. It includes phloem and xylem. They facilitate the transfer of water, nutrients, and food throughout the plant. The xylem consists of parenchyma, fibers, vessels, and tracheids.

This tissue transports the liquid matter to the entire plant. The transportation starts at the root and goes till every leaf. It supports the plant with lignin made components. While the phloem is made up of fibers, companion cells, sieve cells, and sieve tubes. It is responsible for transporting food throughout the plant.

Conclusion

This article was a biology article for competitive exams like UPSC, RRB, SSC, and more. It comes under basic science topics or ideas which are present in most of the competitive exams. This article covers the basic functions of plants, their parts, and their distinctive features.

This has a high chance of appearing in the UPSC Prelims exam. It is because it is a very primary level or basic topic. The chances of it coming in UPSC Mains is comparatively low.

But again if you are a science aspirant then this article will help you build your basic understanding of the subject. All the aspirants must read this article before appearing for the exams.