What are the important parts of plants? CBSE Class 6 exam notes

We see plants everywhere. Plants have different shapes, sizes and colours, and look completely different from animals. Plants grow in the soil and are stationary; they can’t move. If you are preparing for the upcoming CBSE Class 6 exams, and want to score more in Science, then go through the article to learn more about important parts of plants. 

Parts of a plant

1. Shoot system
2. Root system

1. Shoot system: This is the part of the plant that we can see because it lies above the soil. It comprises the leaves, fruits, flowers, stems, bud, node, and internode. 

• Flower: It is the reproductive part of the plant. Seed formation and reproduction occur inside it so that a new flower or plant is formed. Flowers are beautiful and different in colours and shapes. A flower has different parts – petal, pistil, stamen, and sepal. Petals are modified colourful leaves that surround the reproductive parts of flowers. Have you ever noticed rose petals? Petals attract pollinating agents like honey bees, who help in the pollen transportation. The sepal is the green part that protects the flower in the bud. Both petals and sepals are modified leaves. Stamen is the male reproductive organ of a flower. Each stamen contains two main parts —anther and filament. The anther is a sac containing pollen grains. The filament is the stalk-like part of the stamen. The pistil is the female reproductive part of the plant. It is also called carpel. It is the innermost part of the  flower. It has three parts — stigma, style and ovary. Stigma is a sticky receptive organ where  pollen grains settle. Style is the stalk of the pistil. The ovary is the swollen base that contains ovules. When the  pollen comes to  the flower for pollination, the stigma receives it; style  transports it to the ovary, which contains ovules. The pollen combines with  the ovules to form seeds.
• Fruit: After the flowers appear on a plant, fruit is formed inside those flowers. When the formation of the fruit is complete, the flowers around it wither away and fall off. Fruits like apples and mangoes are always formed from a flower, while vegetables like onion and carrot are formed from other parts of the plant.
• Stem: The stem is the upright part of the plant. The flowers, fruits, and leaves are all attached to the stem. The stem bears terminal buds for growth in length. The function of the stem is to give support to the leaves, flowers and fruits attached to it. It also conducts water and minerals from roots to the leaves and fruits. The food produced in the leaves is transported to the roots, fruits and organs of storage through the stem. 
• Leaf: Mostly, leaves are green, but sometimes those can be of different colours. The leaves perform an important function of helping the plants prepare food. A leaf has different parts – leaf base, axil, midrib, margin, tip, vein, lamina and venules. The petiole is a stalk-like structure that connects the leaf with the stem. The surface of the leaf is called the lamina or the leaf blade. Lamina has veins spread all over it. The veins arise  from the midrib, which extends through the center of the leaf. The midrib and veins help transport water and food from one part of the plant to the other. The tip of the leaf is pointed.

            Leaf venation: The veins are present on the leaf in different forms:

1. Reticulate venation: Veins are present in a net-like pattern. For example, mango leaves and apple leaves.
2. Parallel venation: Veins are arranged parallel to each other. For example, banana leaves.

         Functions of leaves:

• Transpiration: Transpiration is the loss of water from the leaves in the form of water vapour. There are tiny openings or pores on the surface of the leaves called stomata, which help in transpiration. The plant uses only 1% of the water absorbed by the roots for photosynthesis. The rest of the water is lost by transpiration. Transpiration helps the plants cool. It is also an important process in the water cycle.
• Photosynthesis: It is the process by which the plants prepare their food by using carbon dioxide and water in the presence of sunlight. Chlorophyll pigment present inside  the leaves is important for photosynthesis. So, leaves help the plants in photosynthesis. Leaves act as the kitchen of the  plants, as the food is prepared there.
• Node: is the part of the stem from where new leaves, flowers, and branches arise. 
• Internode: Suppose there is a node on the stem from where a branch arises. A little further, there is another node that gives rise to a flower. There is a distance between these two nodes. This distance is called an internode.
• Bud: Bud is a small outgrowth that gives rise to a new leaf or a new flower. You all must have seen rosebuds in gardens and how they bloom into new flowers. Bud is always present on a node. The largest bud is that of cabbage. 

1. Root system: The root is the non-leaf, non-nodes bearing part of the plant’s body that typically lies below the soil’s surface. We can not see this part because it lies underneath the soil. The roots hold the plant strongly in the soil. If the plant’s roots are not strong, they will fall off whenever a strong wind blows. Each functional root is covered at the tip by a root cap. The root has five parts- root cap, growing point, region of elongation, root hair zone, and zone of mature cells. Plants whose roots are embedded deep into the soil can stand strong against the wind.

   Functions of the  root:

• They absorb water and minerals from the  soil
• The  anchor the plant to the soil
• They store food in some plants like sweet potato, radish, turnip etc.
• They give mechanical support to the plant
• Roots prevent soil erosion 
• Roots take part in the transport of absorbed water and minerals to the shoot system
• Roots help the free-floating plants balancing

 Types of roots:

• Taproot: These consist of primary roots in the centre and secondary roots from the sides. Secondary roots are also called lateral roots. They have a reticulate venation. For example, carrots, radish etc.
• Fibrous root: Many roots grow from a single point in fibrous roots. They have parallel venation. For example, wheat, rice, maize, onion, banana, sugarcane etc.

Types of plants

Depending on the size of the stem, we can categorise plants into different types:

1. Herbs: Herbs are plants that have short and thin stems. Herbs have green stems. They need very small space for growing, so they can be grown inside planters. Can you grow a tree inside a planter? No. Because they need more space inside the soil for spreading their roots firmly. Their lifetime is short. Herbs are used as a seasoning and also are medicinal. For example, rosemary, thyme, coriander, mint, oregano etc. 
2. Shrubs: Shrubs have hard and thin stems. They are taller in size than herbs. They live for a shorter time. They need smaller space for spreading their branches. For example, roses, tulsi etc. 
3. Trees: We find trees everywhere around us. They have thick and strong stems, which are called trunks. They live for a longer time. They need larger space  for spreading the branches. For example, banyan trees, mango trees etc. There are two types of trees- annual and perennial trees. Annual trees shed their branches every year. Perennial trees are evergreen; they never shed their leaves. 

            Functions of trees:

• Trees provide us shelter against the sun and rain
• Trees produce fruits for us to eat
• Birds build their homes on trees in the form of nests

1. Creepers: These are plants that cannot stand upright as their stems are too weak. They spread on the ground. For example, pumpkin plants, watermelon, muskmelon plants
2. Climbers: These plants take support of the surrounding structures like walls and ladders and grow on them, as they have weak stems. The climbers have organs that help them to cling for support. For example, a cucumber plant, grape plant, money plant etc. The difference between a creeper and a climber is that creepers spread on the ground, while climbers grow upright by taking support from the structures around them. 

Fun facts about plants

• There are 3 lakh 15 thousand varieties of plants known on earth.
• The oxygen we breathe in comes from plants. The main function of plants is to produce oxygen. 
• The basil plant is the tallest plant, with a height of 3.34 metres.
• Some plants are used in the manufacture of medicines.
• Some plants help in relieving stress and induce calmness.
• Cucumber is a not a vegetable; it is a fruit because of the presence of seeds inside it.
• Some trees like Ginkgo Biloba can survive for hundreds of years.
• The wood derived from an average tree can be used to make upto 171,100 pencils.

FAQs

1. How are plants different from animals?

2. What is the difference between fruits and vegetables?

Fruits are formed from the flower of the plant, while vegetables are derived from other parts of the plant. Fruits are mostly sweet, while vegetables are not sweet.

3. What is photosynthesis?

Photosynthesis is the process by which green plants produce their food from carbon dioxide gas and water in the presence of sunlight. Plants have a special pigment called chlorophyll that helps them carry out photosynthesis. Oxygen is released due to photosynthesis, and animals take up this to carry out their respiration.

4. Do plants feel pain?

We feel pain because we have special structures in our body called pain receptors. Pain receptors get activated whenever a painful stimulus is applied to the skin. Plants lack pain receptors. So they do not feel pain.

5. Why do we need to study the parts of plants?

1. Knowledge of the parts of plants and their structure in different plants is essential for recognising or identifying plants.
2. Study of the parts of plants and their functions is required for various aspects of plant life like genetics, anatomy etc
3. It helps us understand the structural adaptations of plants to their environment — for storage, protection, climbing etc.
4. Certain important criteria for the classification of plants are obtained by studying them.
5. Plants with different structures are adopted by horticulturists for growth in lawns, gardens, parks, etc.

6. Why are plants important?

Plants are a very important part of our ecosystem.

1. Plants release oxygen in the air for us to breathe.
2. Some plants like tulsi, aloe vera, and neem have medicinal properties. 
3. Plants act as homes for birds. Have you ever discovered a nest on a tree?
4. Plants act as a protector against air pollution. They keep our air clean.
5. Plants have an important role in maintaining soil quality.
6. Plants provide food for us in the form of fruits and vegetables.
7. Plants keep our water bodies clean by releasing oxygen and taking up carbon dioxide.
8. Plants are aesthetically pleasing. They beautify our surroundings.
9. Plants give us shade against sunlight.
10. Trees provide us with wood that is used to make pencils and paper.
11. Plants take part in the rain cycle.
12. Perfumes are derived from plants.
13. Spices are derived from plants.
14. Plants help maintain the climate.

7. Can plants grow without sunlight?

Some plants can grow without sunlight. Those plants are called shade-loving plants. Examples of such plants are rubber plants, money plants, begonia etc. Those are used inside our homes as decoration pieces.