Each egg has a hard protective outer shell. Inside the shell there is a clear sticky Iiquid called albumen [ also called egg white ). Inside it there is a yellow liquid called yolk that provides food to the body growing inside. This body is called the embryo. The embryo develops into a chicken  only when an egg is kept  warm . The parent bird keeps the egg warm by sitting on it. After 21 days the fully grown chick breaks the egg and comes out. This is called hatching.                                Animals that give birth to young ones produ e milk to feed them are called mammals. These Animals carry their yound ones inside their bodies till they are born. Cow horse tat elephants cat squirrel mongoose etc. belong to this group of Animals Human beings are also mammals.

Bachendri Pal was the first Indian woman and the fifth climbing in the world to climb Mount Everest, in 1984. She was born at Nakuri in Garhwal. At the age of 12, she started mountain climbing with her friends. After her graduation, she joined the Nehru Institute of Mountaineering to be trained as a high altitude  mountaineer. In 1984, she was selected as a member of the fourth indian expedition to Mount Everest. On 23 May 1984 she reached the world highest peak. The base camp also serves as the  entre of operation for climbers. It has normally houses fix machines laptops and other communication equipment. Doctors are available at the camp.

Normally when sunlight falls on the earth some of heat is absorbed by the earth, surface while others are reflected back to space. Carbon dioxide and other gases from a blanket over earth surface trap its heat as a result some heat energy is not allowed to escape. This is known as the green house effect. The increase in the temperature of the earth due to green house effect causes global warming it has become a matter of concern for the environmentantalists. They are finding out ways and techniques to deal with such an alarming situation.

Machinery producing less noise should be used Noisy generators should be kept in a sound proof pollution. Silence zones near schools hospitals residence and offices should should be marked.                                   (  Soil pollution )

The physical and chemical changes in soil that cause harm to plants and animals are called soil pollution. Soil pollution can be caused by excessive use of chemical in agriculture.  Dumping of garbage, polythene bags and plastic in the soil.

Modern water filter used the techraque of RO ( Reverse osmosis). Ans ultraviolet radiation to print water. fresh water in rivers lakes and streams which we. Can readily use forms only 0.3 % all the water available on the earth. we must use water very sensibly we. Should not waist water or pollution water. We can adopt following steps to save water at home: Reuse kitchen water to water plansts in your garden.  Close taps properly after use. Replace or repair leaking taps pipes immediately. Avoid using a shower for bathing as it uses more water. Also avoid the use of a House pipe for washing vehicles. Do not throw plastics and polythene bags into a water sources or a drain. Create awareness about water conservation among people.

In most houses, especially in cities water come through pipes the water is obtained from a nearby water body and sent to a water treatment plant. Once treated and purified the water is distributed throughout the taps in our houses, from where we can get the water supplied through the pipes. In some houses, piped water supply is available only at a certain times in a day. Hence. It is necessary to store water in overhead tanks that it is because freely used all the time.

{Purification of water}

Purification of water is very essential before consuming it. Water can be purified by following methods: 

             Boiling

Water should be boiled for fifteen minutes to kill the germs and bacteria.

          Filtration

It is a common method of water purification. In this method, water is passed through a filering device to remove impurities like dust and germs. The traditional water filter used two or three pots One upon the other to filter water. 

     Water purification 

1. Boiling 2. Chlorination 3. Filtration.

  Chlorination 

Chlorination tablets are mixed in water to kill germs.       

Land thickly covered with trees, bushes and creepers is called a forest. We get many useful things from the trees in a forest such as pulp for paper, fruits, medicines and raw materials for many other products that are produced in factories. Forests are found mainly in areas where there is sufficient rainfall. Ideally, one third of the total area of a country should be one. Fifth of india total area is forest.                         {.Types of forest}

There are different types of forests. These depend on the climate, the kind soil and the amount of rainfall. They are:                1. Tropical Rain Forests.

  2. Mountain Vaetation.

   3. Tropical deciduous forests.

People living in forests  depend on various forest products for living unlike people living in cities or villages. They are called adivasi or tribals. Jarwa, kol, Bhil, Munda , Gond,Khasis,Santhals are some of the adivasi groups living in different forests of India.  Tribal people depend on forest resources for their living women gather various forest products such a tendu leaves, berries bamboo, fruits, sal, seeds, mahua, gum and medicinal plants. From the raw materials collected from the jungles these women make basket mats brooms etc. 

Water pollution 

70 of our planet is covered with water. However only about 3 of earth water is fresh. Fresh water is needed by humans ans plant  so we should control the pollution of water.  Addition of pollution into water bodies such as rivers or lakes is called water pollution.  Bathing animals  washing cloths and utensils in water bodies also lead to pollution. Immersion of idols during festivals. Chemical wastes bodies. If harms and kills aquatic flora and fauna. Pollution water caues diseases like typhoid diarrhoea cholera jaundice.

Water pollution 

70 of our planet is covered with water. However only about 3 of earth water is fresh. Fresh water is needed by humans ans plant  so we should control the pollution of water.  Addition of pollution into water bodies such as rivers or lakes is called water pollution.  Bathing animals  washing cloths and utensils in water bodies also lead to pollution. Immersion of idols during festivals. Chemical wastes bodies. If harms and kills aquatic flora and fauna. Pollution water caues diseases like typhoid diarrhoea cholera jaundice.

As water is a bad conduct of heat so there is alway an uneven heating pattern noticed in case of land mass and mass and water bodies. In summer the landmass of northern Indian is much hotter that the surrounding water in the oceans most of the times. The air above the land becomes hot up and rise and the wind from the ocean carrying water bodies these winds called winter monsoon bring scanty rainfall to coastal tamil Nadu  as they take moisture while blowing over Bay of Bengal.

Differant types of storms are caused by strond by strong air cirrents and are accompanied by lightning heavy rains and high speed winds lightning there the storms may occur on land or over the seas.                             Thunderstorm.               Thunderstorm occur in hot humid tropical areas such as india most frequently. the air over the land gets heated becomes light  and rises. In doing so the water vapour condenses fast form tiny droplets of Water which freeze forming ice particles during the condensation of water  vapour and freezing of droplets. A large a large anount of heat is given out which further pushes the air up at a  higher speed.