(i) Leaves are changed into spines.
(ii) The stem is green and fleshy.
7. Write the names of some water plants.
Water hyacinth, Pistia, Lotus, Water lily
IV. Answer the following questions.
1. Write any two functions of each:
(a) Stem
(i) Supports the whole plant,
(ii) Transports food from leaf and water from root.
(b) Root
(i) Fixes the plant firmly to the soil
(ii) Absorbs water and minerals from the soil.
(c) Flower
(i) Develops into fruit
(ii) Helps plant to reproduce.
2. Why is leaf called food factory of the plant?
Leaf prepares food for the plant with the help of water, carbon dioxide sunlight, and chlorophyll. Hence it is called the food factory of the plant.
3. Differentiate between taproot and fibrous root.
Taproot:
(i) Thick main root that goes deep into the soil.
(ii) Side roots are developed from the main root.
Fibrous root:
(i) No main root and the roots do not go deep into the soil.
(ii) Roots are developed from the base of the stem.
4. Give two examples of:
(a) Fruit having only one seed
Mango, Coconut
(b) Fruit having many seeds
Papaya, orange
5. Name two free floating plants.
(i) Water hyacinth.
(ii) Pistia.
6. Look at the picture of a water lily.
(a) Which parts of the plant can you see?
We can see the flowers and the leaves, at the surface.
(b) Where are the plant‛s roots and stem?
The plant's roots and stem are in the mud under the water.
V. Project
Collect the information about vegetables that were cooked in your friends houses for the last two days. Fill the table with the particulars.
From the table, answer the following questions.
(a) In how many houses did they cook leafy vegetables?
one
(b) Which vegetable is cooked the most?
Cauliflower
Warm-up
Unscramble the words and label the parts of the plant.
( ETSM, TORO, ELFA, FURTI, LOFEWR , SDEE )
Let us Do
Take two small potted plants. Cut the root of one of the plants and fix it in the pot. Now water the plants for two to three days. You will observe that the plant without roots will wilt and die. In the absence of roots, plants die.
This activity proves that the function of the roots is to absorb Water and Minerals from the soil.
Let us Write
True or false
1. The roots grow into the soil. (True)
2. Fibrous root has a main root. (False)
3. Root absorbs water from soil. (True)
4. Potato stores food in its root. (False)
5. Grass has fibrous roots. (True)
Which method is easier to identify? Touching or smelling?
Answer : smelling
Let us Do
Collect the leaves of different kinds of plants.
1. Arrange the leaves from small to big. 2. Group the leaves based on its colour.
Let us Write
Fill in the blanks.
1. Stem grows towards the sunlight.
2. Leaves originate from the Stem.
3. Green part of the plant that makes food is called Leaf.
4. Stem gives support to the whole plant.
5. Water from soil is absorbed by the root of the plant.
Think and Write
1. List out the fruits that do not have seeds. Banana, pineapple.
2. Write down the names of the fruit trees that you have never seen, but have tasted their fruits. apple, strawberry.
Let us Do
Connect the leaf with its fruit.
Let us Connect
Match the plants with their living places.
Let us Try
A. Select the ‘INCORRECT‛ statement from the following.
1. Desert plants grow in hot, dry and sandy places.
2. Plants in coastal areas tolerant to saline water.
3. Mountain plants have needle like leaves.
4. Teak is an example of desert plant. (Incorrect)
B. Tick (√) the odd one.
1. Teak, Tamarind, Mango, Opuntia ✔
2. Opuntia, Aloe vera, Pine ✔, Date palm
C. Circle/underline the places which are land habitats.
Forest, Pond, Mountain, River
Tree, Ocean, Desert, Cave
Let us Try
A. Mark ‘L” for land plants and ‘W‛ for water plants.
B. Colour the Water hyacinth plant.
C. Write true or false.
1. Fixed rooted plants are present in water bodies. (False)
2. Leaves of lotus are submerged in the water. (False)
3. Lotus plants are found in many ponds. (True)
4. Water hyacinth freely float with the help of spongy body filled with air. (True)
After learning this lesson, students will be able to
* identify the parts of a plant
* understand the functions of different parts of a plant
* classify plants based on their habitat
Unit 3 Plants
Warm-up
Unscramble the words and label the parts of the plant.
( ETSM, TORO, ELFA, FURTI, LOFEWR , SDEE )
I. Plants are nature's gift
A plant has many parts. Each part has a set of function to do.
The basic parts of a plant are root, stem, leaf, flower, fruit and seed.
Let us learn about various parts of the plant, their structure and function.
Root
The root is a part of the plant that usually grows under the soil. Roots can be of different shapes and sizes. It grows away from sunlight into the soil. They are of two main types: tap root and fibrous root.
Taproot
Taproot has one main, thick root. It grows from the radicle and goes deep into the soil. Many small thin roots grow out from the main root. Plants such as carrot, beetroot, turnip, mango and neem have taproots.
Fibrous Root
A fibrous root consists of many thin roots of different sizes. They grow from the base of the stem and all of them are bunched together. They do not go deep into the soil. Plants such as grass, paddy, wheat and onion have fibrous roots.
Functions of Root
Fixation: Root fixes the plant firmly to the soil. Without the roots, a plant would fall on the ground.
Absorption: Roots absorb water and minerals required for the plant from the soil.
Storage of food: In some plants, roots store food. E.g., Carrot, Radish, Beetroot.
Difference between taproot and fibrous root
Taproot:
Thick main root that goes deep into the soil.
Side roots are developed from the main root.
Looks like a long tap E.g., Tamarind, Guava.
Fibrous root:
No main root and the roots do not go deep into the soil.
Roots are developed from the base of the stem.
Looks like a bunch. E.g., Corn, Sugarcane.
Do you know
Avecinnia plants have roots above the ground.
Let us Do
Take two small potted plants. Cut the root of one of the plants and fix it in the pot. Now water the plants for two to three days. You will observe that the plant without roots will wilt and die. In the absence of roots, plants die.
This acivity proves that the function of the roots is to absorb Water and Minerals from the soil.
Let us Do
Take two coconut shells. Fill them with soil. Sow green gram in one and paddy in another. Keep them under sunlight and water them. After a week observe the features of roots.
Let us Write
True or false
1. The roots grow into the soil. (True)
2. Fibrous root has a main root. (False)
3. Root absorbs water from soil. (True)
4. Potato stores food in its root. (False)
5. Grass has fibrous roots. (True)
Stem
The stem is the main part of the shoot system. It grows towards the sunlight. It looks green when it is young. Branches, leaves, buds, flowers and fruits grow from the stem.
Herbs such as coriander and mint have a thin and weak stem. Trees such as peepal and banyan have very strong and thick stem called trunk. As trees grow older, their trunks grow wider.
Functions of the Stem
* It supports the whole plant.
* It transports food from leaf and water from root to various parts of the plant.
* Some stems store excess food in them. E.g., Potato, Onion.
Leaves
Leaves originate from the surface of the stem. It is flat, thin and green. Leaves of different plants have different shapes, sizes and colours. Some leaves have even a specific smell.
Functions of Leaf
* Leaf prepares food for the plant with the help of water, carbon dioxide and in the presence of sunlight and chlorophyll. This process is called photo synthesis. Hence, it is called the food factory of the plant.
* The loss of water in the form of gas (water vapour) happens through the tiny pores in the leaves. This process is called transpiration. It gives cooling effect to the plant.
* Leaves of some plants are edible and rich in nutrients. E.g., Greens, Cabbage.
Let us Play
Collect the leaves of coriander, mint, eucalyptus, tamarind, amla, neem and tulsi.
Select two students and cover their eyes with a handkerchief. Give one leaf to each of them. and ask them to identify the leaf by touching or and the other by smelling it. Find out who identifies more leaves.
Which method is easier to identify?
Touching or smelling?
Answer :smelling
Let us Do
Collect the leaves of different kinds of plants.
1. Arrange the leaves from small to big.
2. Group the leaves based on its colour.
Let us Write
Fill in the blanks.
1. Stem grows towards the sunlight.
2. Leaves originate from the Stem.
3. Green part of the plant that makes food is called Leaf.
4. Stem gives support to the whole plant.
5. Water from soil is absorbed by the root of the plant.
Flowers
Flowers are the most beautiful part of the plant. They are of different shapes, size, colours and fragrance. A flower develops from the bud. The soft and brightly colored part of a flower is called petal. The green part that lies under the petal and supports it is called sepal. The middle of the flower has two parts called the stamen and pistil.
Functions of the flower
* It develops into fruit.
* It helps plant to reproduce.
Fruits and Seeds
Fruit is the fleshy part of the plant. The fruits are developed from the flowers. Most fruits have seeds.
* Some fruits have only one seed. E.g., Apricot, Mango, Coconut and Peach.
* Some fruits have many seeds. E.g., Papaya, Watermelon and Orange.
* Some are seedless. E.g., Pineapple and Banana.
New plants are grown from seeds.
Think and Write
1. List out the fruits that do not have seeds. Banana, pineapple.
2. Write down the names of the fruit trees that you have never seen, but have tasted their fruits. apple, strawberry.
Let us Do
Connect the leaf with its fruit.
IV. Plants and their habitat
Plants grow almost everywhere on Earth i.e. on land (terrestrial plants) and in water (aquatic plants). The plants adapt to their surroundings and hence have special characteristics based on their habitat.
The natural home of a plant is called its habitat. Plants make suitable adjustment with their surroundings to meet their requirements. This is known as adaptation.
Terrestrial or Land Plants
The plants that grow on the land are of different habitats such as deserts, plains,mountains and forests. Let us learn about the adaptation of different land plants.
Plants in Desert
These plants grow in hot, dry and sandy places. Deserts get very less rainfall and experience high temperature. Hence, there is scarcity of water. Let us see how these plants have adapted to this habitat.
* Leaves are changed to spines to reduce the loss of water.
* The stem is green and fleshy. They store water and produce food.
* These plants have a long root that goes deep into the soil.
E.g., Opuntia, Date Palm and Aloe vera.
Plants on Mountain
These plants grow in cold and freezing places. There is a cool weather in mountain. Let us see how these plants have adapted to this habitat.
* These trees are conical in shape. This shape allows snow to slide from the trees easily.
* Needle like leaves help them to survive in cold conditions like snow.
* These trees do not shed leaves.
* They have cones instead of flowers. These cones protect the seeds during harsh winter. E.g., Pine tree.
Plants in Plains
* Plants in plains need to adapt to both dry conditions and extreme temperatures.
* They grow in warmer climate and usually shed their leaves in winter to protect themselves from cold.
* They have flat and broad leaves.
* They have thick and woody stem. E.g., Mango, Banyan, Teak.
Do you know
Banyan, Peepal and Tamarind trees live more than hundred years.
Plants in Coastal Areas
* They are tall and mostly straight.
* The leaves are called frond.
* The frond look like feathers meant for protection from wind.
* These plants tolerant to saline (salt) water. E.g., Coconut tree.
Let us Connect
Match the plants with their living places.
Let us Try
A. Select the ‘INCORRECT’ statement from the following.
1. Desert plants grow in hot, dry and sandy places.
2. Plants in coastal areas tolerant to saline water.
3. Mountain plants have needle like leaves.
4. Teak is an example of desert plant. (Incorrect)
B. Tick (√) the odd one.
1. Teak, Tamarind, Mango, Opuntia Opuntia ✔
2. Opuntia, Aloe vera, Pine, Date palm Pine ✔
C. Circle the places which are land habitats.
Forest Pond Mountain River
Tree Ocean DesertCave
V. Plants in Water
The plants that grow in water bodies like ponds and lakes are called water plants or aquatic plants. They are classified into following types.
Free floating plants
Fixed rooted plants
Submerged plants
1. Free Floating Plants
* These are found on the surface of the water.
* They freely float with the help of spongy body filled with air.
* They have poorly developed roots.
E.g., Water hyacinth (Agaya thamarai), Pistia.
2. Fixed Rooted Plants
* These plants have root that are fixed in the bottom of the water bodies.
* These plants have air tubes in their stem to help them float.
* Their leaves are broad and coated with wax to make them water proof.
E.g., Water lily, Lotus.
3. Submerged Plants
* These plants are completely submerged in the water.
* Their stem is thin and leaves are very small.
* There is no opening on the leaf surface.
* They breathe through stem. E.g., Vallisneria, Hydrilla.
Let us Try
A. Mark ‘L” for land plants and ‘W’ for water plants.
B. Colour the Water hyacinth plant.
C. Write true or false.
1. Fixed rooted plants are present in water bodies. (False)
2. Leaves of lotus are submerged in the water. (False)
3. Lotus plants are found in many ponds. (True)
4. Water hyacinth freely float with the help of spongy body filled with air. (True)
Nature is full of wonders. Shall we explore some of them?
Lily
Why does water not stay on the leaf of the lily?
The leaf of a lily has a waxy coat on the upper surface. It has a notch too. Water does not stay on the leaf because of the notch and the waxy coating.
Nuts under the soil
Usually nuts are seen on the stem part of the plant. In groundnut plants, the nuts are under the soil.
Nuts are also called seeds.
Kurinji
The Kurinji or Neelakurinji shrub is found in the Nilgiri mountains in Tamil Nadu.
The flowers of the Neelakurinji bloom only once in 12 years.
They are purple blue in colour. Nilgiri, the Blue Mountain, gets its name from these flowers.
Touch Me Not Plant
Have you seen this plant? It is found in many places.
It is a small herb. When you touch the leaves of this plant, they close. So it is called the ‘Touch Me Not‛ plant. The leaves open a few minutes later.
Calotropis – Erukku
Calotropis is a shrub. It has a group of waxy flowers. Its flowers are either white or lavender in colour. It is also known as the ‘Crown Flower‛ since it looks like a crown.
Draw and colour the Erukku leaf.
Colour and Fragrance of Flowers
Flowers have beautiful colours and many have fragrance. Insects are friends of the flowers. They are attracted by the colour and smell of flowers. Flowers have nectar. Insects and birds come to suck the nectar from the flowers.
Many of the flowers that bloom at night are white in colour and they have a wonderful fragrance.
Many of the flowers that bloom during the day have attractive colours and are less fragrant.
Join the dots and colour the picture.
Wonders of Nature-Animals
Chameleon
Have you seen this animal? It is called a chameleon. It is a type of lizard. It changes its skin colour to merge with the surroundings. This helps it to escape from its enemies.
Lizard
Have you seen a lizard clinging upside down on the ceiling? Lizards have toe pads that help them stick on to the wall. If the tail of the lizard is cut, it grows back in one or two months.
Spider
Do you remember that insects have only six legs? Spiders are notinsects because they have eight legs. Spiders make threads called spider silk with which they create spider webs. The threads in the web are very strong and sticky. The webs help the spider catch insects like flies for its food.
Dog
Dogs can smell much better than us. They can even hear very soft sounds and sounds from far away. They are trained and used by the police to identify thieves. These dogs are called sniffer dogs. They are also used to search for people during natural disasters like earth quakes.
Rat
The rat is a small animal that lives in houses and fields. Rats can live withoutwater for even longer periods of time than camels. They can bite hard wood with their teeth. Some of their teethkeep growing. Rats grind their teeth to prevent them from becoming too big.
Snail
The snail has two pairs of feelers on its head. One pair is long and the other is short. The eyes are on the longer pair. If we touch the snail, it pulls its body backinto its shell like a tortoise.
