Current Affairs 3rd Class

Living and Non-living Things    

Things around us can be divided into two categories man- made things Natural things

 

The things which are made by man are called man-made things. Television, chair aeroplane, etc., examples of man-made things.

 

The things which occur in the nature ar natural things. Trees, sun, animals rocks, etc., are examples of natural things.

 

Natural things are again divided into two categories: living things and non-living things.

 

The things which have life in them are called living things. Animals, people, trees are living things.

 

The things which do not have life in them are called non-living things. Rocks, clouds water, etc., are some examples of non-livings things.

 

Feature of livings things:

  (a) Living things move: Animals move from one place to another. Fish swim. Birds fly. Plants also show movement.   (b) All living things grow on their own: Seeds grow and become trees. Babies grow into men or women. Egg grow to become hen.   (c) All living things need food: To grow and live, living things need food. Without food living things cannot live and will starve to death.   (d) All living things breathe in and out: Living things cannot live without air. They take in air through nose or gills or stomata   (e) All living things grow old and die: A stone remains unchanged forever but we cannot. We grow old, become weak and die   (g) All living things reproduce: Human beings give birth to babies. Animals either lay eggs or give birth to young ones.  

Features of non-living reproduce:

  (a) Non - living things do not have life.   (b) Non - living things cannot move on their own   (c) Non - living things do not breathe.   (d) Non- living things do not grow.   (d) Non - living things do not eat food and do not grow old and die.   (f) Non - living things do not feel.   (g) Non - living things do not reproduce.  

Reproduction

The process by which living things produce their own kind is called reproduction. Only living things reproduce

Animals and Plants    

Both plants and animals are living things. But they are different from each other in many ways.

 

The following are the differences between plants and animals.

  (a)        Movement Animals move from one place to another. Human beings move from one place to another, birds fly and fish swim. But plants are fixed to the ground. Plants cannot move from one place to another place like animals. However, plants show movements.   (b)        Food Habits Animals have different food habits. Some animals depend completely on plants and eat them. Such animals are called herbivores or plant-eating animals, e.g., Goat, Cow. Some animals like tiger and lion eat other animals. They are called carnivores or animals that feed on other animals.   Some animals eat both plants and other animals. They are called omnivores.   All green plants produce their own food. Plants absorb water and minerals through their roots, carbon dioxide through their leaves and combine them in the presence of sunlight to make their food.   However, non-green plants like moulds and mushrooms cannot make their own food. They get their food from decaying matter in the soil.   (c)        Breathing habits Animals breathe through the nose, lungs, gills or air holes. Some animals such as insects, e.g., houseflies and cockroaches have air holes on their body to breathe. These air holes are also called spiracles. Plants have small pores on their leaves to breathe in and out. These pores are called stomata.   (d)        Reproduction Some animals like birds and snakes lay eggs while cats, dogs, lions and human beings give birth to young ones. Plants can reproduce from seeds, stems, roots, bulbs or other parts of the plant.   (e)        Sense Organs Animals have sense organs like skin, nose, eyes, ears and tongue. These organs help them to find the food and express their feelings. Plants do not have any sense organs. However they respond to light, gravity, water, etc. Some plants like touch-me-not can respond to touch.

Animals (Their Food and Home)    

Animals are living things. They need food to grow and to build their bodies.

 

Plants make their own food but animals cannot make their own food. Some animals like cows, horses, goats and sheep eat grass and other plants. They are called herbivores.

 

Some animals like frogs, dogs, cats, lions and tigers eat the flesh of those animals which eat plants. Such animals are called carnivores.

 

Some animals like bear and human beings eat both plants and other animals. Such animals are called omnivores.

 

Food chains are diagrams showing the eating habits of various animals. Food chains always start with plants since they are the producers of food.

In the above food chain grass produces food. It can prepare food on its own. So, it is the producer. Deer cannot make its own food. It eats grass. It is a herbivore. Lion also cannot make its own food. Lion eats the deer. It is a carnivore.  

Some animals are useful to us. We keep such animals in our houses and farms. These animals are called domestic animals. Animals like cows, buffaloes and goats give us milk. Animals like camels, donkeys, oxen, horses and elephants carry loads and perform various works. Birds like hens and ducks give us eggs which have lots of energy.

 

Some animals such as dogs, lions, foxes and tigers have long, sharp and pointed teeth called canines in front and sharp edged teeth at the back to carve flesh from the bones and to crack bones. They act like scissors (shears).

 

Animals like frog, lizard, snake and crocodile do not bite or chew the food. They swallow their food as a whole.

 

Animals like rats, rabbits and squirrels have very sharp front teeth which help them in cutting the seeds, fruits and other materials. Such teeth are called gnawing teeth and they gnaw their food.

 

Some animals like babies of cats, dogs, cows, horses and buffaloes suck liquid food. The suck milk from their mothers.

 

Grass-eating animals like cows, buffaloes, horses and goats have strong flat front teeth to cut the grass and leaves of the plants. They also have strong and broad back teeth to grind the food.

  These animals swallow the food without chewing it. After sometime they bring the food from their stomach back into the mouth and then they chew the food. This is called chewing the cud and such animals are called cud-chewing animals.  

The leech sucks the blood of animals like cows and buffaloes. It sticks to the animals with the help of suckers and sucks the blood.

 

The butterfly has a long mouth part with which it sucks nectar from various flowers.

      

Spiders make webs and traps small insects like flies and mosquitoes and then eats them.

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Birds      

Birds are the most beautiful animals on earth. Most of them can fly.

 

The body of a bird is made of a strong framework of bones. These bones are hollow and filled with air. Its body is light but strong. It is boat-shaped and so it is able to fly in the air easily.

 

A bird has wings in place of arms. These wings have feathers which help it to fly.

 

Birds have strong muscles which move the wings up and down. These muscles attach the wings to the breast bone and are called flight muscles.

 

A bird's body is covered with feathers. Some of the feathers cover the body and keep it warm. These feathers are called down feathers.

 

The feathers attached to the wings and tail-bone, help the bird to fly. These feathers are called the flight feathers.

 

The tail of a bird acts like the rudder of a boat. It is made up of feathers and helps the bird to change its direction during flight.

 

When a bird wants to fly, it flaps its wings and goes up gradually into the air. When the bird flaps its wings, the air under the wings pushes the bird up. When it reaches high in the air, it does not need to flap its wings any more.

 

Bird's flight consists of two main movements. They are upstroke and down stroke. When the wings move upwards, the movement of the wings is called upstroke movement. When the wings move downwards, the movement of the wings is called down stroke movement. The tail feathers are used to steer, brake and change the direction.

 

Birds fly to different extent. Some birds like pigeon and crow fly over long distances. In the olden days, pigeons were used to carry letters from one place to another.

 

Birds like cock and hen fly only short distances. They usually walk.

 

Some birds like eagle, vulture and kite fly at great heights. They have sharp eyes to locate their prey on the ground.

 

Some birds like sparrow fly at low heights.

 

Some birds like Kiwi, Ostrich and Penguin do not fly at all. They move on the ground with the help of their legs. Such birds are called flightless birds.

 

Some kind of birds live in water. They have oil glands which keep their feathers waterproof.

   

This oil does not let their feathers get wet or damaged by water. They have webbed feet to swim in the water. Ducks, swans, gulls, pelicans and cranes are some examples of water birds.

Beaks and Claws of Birds      

Birds have no teeth but they all have beaks and claws. Different kinds of birds have diffeffent kinds of beaks and claws. Beaks and claws tell us a lot about birds.

 

Beaks help the birds to pick up their food and also to protect themselves from the enemies. Claws help in catching, holding and eating food. They protect the birds from their enemies. They help the birds in walking, in swimming, in climbing and perching.

 

Short, hard and horny beaks can be found in sparrows, pigeons, peacocks and finches which eat nuts, grains and seeds. They break their food into small pieces with their beaks and they also use them to drive away other birds.

 

Parrots have hooked beaks. It helps them to crack nuts and hard fruits. The curved beak helps them to eat even hard and unripe fruits. They are useful in climbing.

 

Eagles, vultures, kites and hawks have strong, sharp and hooked beaks which help them to tear flesh into small pieces.

 

Birds like woodpeckers which make holes in the trunks of trees to pick insects have chisel-shaped strong and heavy beaks.

 

Swallows have short and broad beaks. Their mouths are very sticky inside. Swallows go round and round in the air with their mouth open. They catch insects and flies which stick inside their mouth.

 

The hoopoe has a long, slender and curved beak which it uses to pull out insects from holes in the ground.

 

Ducks have flat and broad beak. This is used for digging up the mud under water. The beak of the duck has got strainers all along the edge. Water and mud go out along these strainers and small plants or tiny water animals remain in the mouth.

 

Kingfishers and storks have broad, long and pointed beaks which help them to catch fish from the rivers and ponds.

 

Sunbirds have long, pointed and thin beaks. Their beaks help them to suck nectar or juice from the fruits and flowers.

 

Perching birds like the crow, sparrow and mynahs have long, slender claws. They have four toes three in the front and one at the back. This kind of toes help the birds to hold the branches of trees firmly and they can even sleep while perching. Perching birds hop on the ground.

 

Climbing birds like parrot and kingfisher have two toes in front and two at the back. Climbing birds can cling to the trees.

 

Preying birds like the eagle, hank and owl have very strong and sharp claws which help them to catch and hold their prey very firmly. These birds may carry their prey to long distances.

 

Scratching birds like hens and cocks use their claws to scratch the earth for seeds and worms. These birds have strong more...

Birds and Their Nests    

Many birds build nests. Different birds build different types of nests in different places with different types of materials.

 

In our India, birds mostly build their nests in the months of February and March before the summer and rains.

 

Birds build nests to lay, Tiatch eggs and reproduce young ones. They build nests to protect the young babies from heat, light, cold and rain.

 

Birds usually build their nests where enemies cannot harm them and where they can easily get their food.

 

Most birds build their nests on trees, in broken walls, old buildings, ventilators, etc.

 

Birds use grass, feathers, twigs, paper, old clothes, grass, cotton, wool, small leaves, etc., to build their nests.

 

Sparrow and pigeon make their nests on branches of trees, windows and ventilators of  houses and other places with bits of straw, grass,  eaves, pieces of clothes, cotton threads, feathers, etc.

 

A tailorbird makes its nest out of two or three large leaves. It uses its sharp beak like a needle to sew and join the leaves together with bits of wool, cotton or spider's web. The nest is lined with grass, thread and dried grass to keep it warm and cozy.

 

The weaverbird weaves a nest out of grass, finer strips of palm or banana leaves. The nest hangs down from a branch of tree and the entrance is from the lower end.

 

A woodpecker cuts a hole in the trunk of a tree with its sharp and hard bark. The hollow space is lined with chips of wood to make it cozy and warm.

 

A bulbul makes its nest with dry grass in hedges and bushes. Its nest is like a deep cup. The eggs and young birds do not fall out of it.

 

Vultures make big nests on tall trees with sticks. Their nests look like a shallow cup.

 

Penguins collect few pebbles and stones on the ground to make their nests.

 

Patridges and ducks dig holes in the ground with their beaks and feet to make their nests. They put some grass and leaves to keep the nest warm.

 

Owls build nests in the hollow of a tree or a wall and line it with feathers and grass.

 

Koels do not build nests and cleverly lay their eggs in a crow's nest. The mother crow hatches them as her own eggs and feeds them along with their own babies because they look quite alike.

 

When the nest is ready, mother bird lays the eggs. Mother bird and father bird sit on them to keep them warm. Father bird also protects the eggs from enemies. When the shell of the egg breaks and baby bird comes out they have no feathers and their eyes are closed. They are week. Mother bird feeds them. Parent birds teach them more...

Plant Life    

Plants are living things. They need air, water, minerals and light to prepare food and grow.

 

A plant consists of two main parts: root system and shoot system.

 

The part of the plant which remains under the ground is called root and the part which remains above the ground is called shoot.

 

Usually roots are of two types: fibrous roots and tap roots.

 

When a number of roots grow from the end of the stem, it is called fibrous root. Plants like onion, grass, wheat and rice have fibrous roots.

 

When a long main root grows from the end of the stem and many small side roots grow from the main root, it is called a tap root, e.g., bean, balsam, mustard and mango.

 

Roots fix the plant to the soil. The tiny hairs on the root absorb water and minerals from the soil and push it up into the shoot. In some plants like carrot, radish, turnip and beetroot. The roots store food in them.

 

Stem holds the plant upright on the ground. Stem bears the branches, leaves, fruits and flowers.

 

Stem carries water and minerals from roots to all the other parts of the plant. Stem also transports food prepared by leaves to different parts of the plant.

 

Leaves are also called food factories of the plants because it is the leaves that manufactures the food.

 

Leaf has a flat and broad part called leaf blade which has tiny holes. These holes are called stomata. Plants breathe air in and out through these stomata.

 

Each leaf has a main vein and many side veins coming out of it. Veins bring water and minerals to the leaves.

 

Leaves contain a substance called chlorophyll. It helps making food using carbon dioxide and water in presence of sunlight. The process by which plants make their food from air, water and sunlight is called photosynthesis.

 

Flowers are the most beautiful part of the plant. They help in reproduction because they grow into fruits and seeds.

 

Fruits are formed from flowers and have seeds in them. Some fruits like mango have one seed while pear, tomato, papaya have many seeds. Banana has no seeds.

 

There are two methods of sowing seeds: direct method and indirect method. In direct method seeds of crop plants like wheat, maize, gram, beans and peas are scattered and sown directly in the fields. Seeds of crops like rice are grown first in small seedbeds, when the seedlings are few inches high, they are taken out and planted in the fields. This method is called indirect method or transplanting.

   

Soil    

Soil is formed by the breaking up of rocks. By the action of sun, wind and rains rocks are broken down into small pieces. The acids produced by the roots of plants also help to break down the rocks. These pieces of rocks are carried to other places by running water and strong winds.

 

Different places have different types of soil. The type of soil depends upon the kind of rock from which it is formed. Soils differ in the size of the grains and different constituents present in it.

 

Most of the soils contain coarse particles of gravel, small pieces of stones, sand particles clay, moisture and humus. Humus is made up of rotten leaves and decayed bodies of plants and animals. Humus is dark brown or black in colour.

 

There are four kings soil: gravel, sandy soil, clay and loam.

 

Gravel is made up of very large grains which do not hold any water between them. They hold a lot of air.

 

The sandy soil has grains smaller than those of gravel. It is grey or brown in colour. The particles are lossely packed and there is lot of air in the spaces between the particles. If we pour water on a heap of sandy soil, water sinks quickly. Sandy soil is mostly found in the deserts and on the beaches. Water drains easily through sandy soil.

 

Clay is made up of very fine grains which stick together. Clay can hold a lot of water but very little air. Clay is used for making toys and other articles.

 

Loam is a kind of soil which we get if we mix equal amount of sand and clay. Loam can hold enough water and air for the use of plants. Loam to which humus has been added makes a soil which is best for the growth of plants.

 

Air and Water  

Air and water are necessary for our living. Without them all plants and animals would die.

 

Our earth is surrounded by a layer of air called atmosphere. Atmosphere contains oxygen. Oxygen helps to burn the food in our body and give energy.

 

As we go higher from the earth, air decreases. On the mountains, the air is thinner.

 

We all need water. We use water for drinking, bathing, cooking, washing our clothes, etc. Plants and animals too need water. Without water all the living things would die.

 

The water we see is in liquid form. It can be poured into a vessel. Water takes the shape of the vessel it is in. It has no fixed shape.

 

We cannot see or feel the water in the air because it is in the form of gas. This gas is called water vapour. When water is kept in a refrigerator it changes into ice. Ice is the solid form of water.

 

Water can be found in three forms-solid ice, liquid form of water and gaseous form of water vapour.

 

Seas, ocean, rivers, ponds and lakes are big resources of water. Polar ice caps and mountain peaks contain ice.

 

When we heat a solid it becomes liquid. Ice which is a solid when heated becomes water which is a liquid. This process of heating ice to change it into water is called melting.

 

When a liquid is heated it it becomes a gas. When liquid water is heated in a kettle we can observe steam coming out of it. Steam is nothing but water vapour. Heating water to change it into water vapour is called boiling or evaporation.

 

When a gas is cooled it becomes liquid. When we cool the water vapour it becomes liquid water. This process of changing water vapour into water by cooling is called condensation.

 

When liquid water is further cooled, it becomes ice. This process is called freezing. The refrigerator in our home freezes water into ice.

       

Rain gauge is an instrument used to measure how much rain has fallen. It is a tall round metal. Can Inside this can a large collecting funnel which empties rain water into a narrow centimeters of rain has fallen.

       

Weather  

Weather changes all the time, from day to day and from month to month. Weather depends upon the Sun, clouds, wind and rain.

 

The Sun gives us heat and light which make our days warm. Sun is very hot in the afternoon because the rays fall directly on us. In the mornings and evenings it is not very warm because we get slanting rays from the sun. In the nights, no heat or light comes from the sun. Therefore, days are hot and nights are cool. And also days are hotter in summer but cooler in winter.

 

Cloudy days are cooler than sunny days because clouds obstruct the Sun's rays. Cloudy nights are warmer than the clear nights because clouds do not allow the heat of the Earth to escape.

 

Clouds are classified into four categories. The clouds which look like locks of hair are called cirrus clouds. The puffed-up cottony clouds are called cumulus clouds. The clouds which are like sheets or layers are called stratus clouds. The clouds that give rainy weather are called nimbus clouds.

 

Air currents or flowing air is called wind. When the wind blows very softly, it is called breeze. Strong winds are called storms.

 

Winds also affect the weather. During summer, hot winds called 'loo' make the weather very unpleasant and uncomfortable. During winter cold winds that flow make the days very cold.

 

Some clouds bring us rain. When it rains, the Earth is cooled and plants get water. Farmers need water for their crops. But, too much rains cause floods which damage crops, buildings and human beings.

 

Water evaporates from the lakes, seas and oceans due to sunlight. This water vapour rises above into the atmosphere and cool down to form drops of water. These drops of water come closer to form clouds. When the clouds cool down, it rains. This rain water flows down to ponds, lakes, rivers and finally seas. In this way water flows from oceans to atmosphere to land and finally again to oceans. This is called water cycle.

 

When the weather remains almost the same for a period of time. We call this period a season. We have four seasons in our country. They are summer season, rainy season, winter season and spring season.

 

In summer, days are longer, very warm and dry. Afternoons are very hot and we sweat a lot. We prefer to stay indoors and sit under shady trees. We wear light and cotton clothes in the summer. We drink lots of water, cool drinks and eat ice cream. We eat fruits like water melon, mangoes and litchies.

Rainy season is also called monsoon and it comes after summer. Dark clouds fill the sky and bring us rains. When it rains, it becomes very nice and cool. When it does not rain, weather becomes hot and humid and we more...