- 01 Nutrition in Plants
01 Nutrition in Plants
I n Class VI you learnt that food is essential for all living organisms. You also learnt that carbohydrates, proteins, fats, vitamins and minerals are components of food. These components of food are necessary for our body and are called nutrients
- 02 Nutrition in Animals
02 Nutrition in Animals
You have learnt in Chapter 1 that plants can prepare their own food by the process of photosynthesis but animals cannot. Animals get their food from plants, either directly by Eating plants or indirectly by eating animals that eat plants. Some animals eat both plants and animals. Recall that all organisms including humans require food for growth, repair and functioning of the body. Animal nutrition includes nutrient requirement, mode of intake of food and its utilisation in the body.
- 03 Fibre to Fabric
03 Fibre to Fabric
In Class VI you have learnt about some fibres obtained from plants.You also learnt that wool and silk fibres are obtained from animals. Wool is obtained from the fleece (hair) of sheep or yak. Silk fibres come from cocoons of the silk moth. Do you know which part of the sheep’s body yields fibres? Are you aware how these fibres are converted into the woollen yarn that we buy from the market to knit sweaters? Do you have any idea how silk fibres are made into silk, which is woven into saris?
- 04 Heat
In Chapter 3 you learnt that woollen clothes are made from animal fibres. You also know that cotton clothes are made from plant fibres. We wear woollen clothes during winters when it is cold outside. Woollen clothes keep us warm. We prefer to wear light coloured cotton clothes when it is hot. These give us a feeling of coolness. You might have wondered why particular types ofclothes are suitable for a particular season.
- 05 Acids, Bases and Salts
05 Acids, Bases and Salts
We use in our daily life a large number of substances such as lemon, tamarind, common salt, sugar and vinegar. Do they have the same taste? Let us recall tastes of some edible substances listed
- 06 Physical and Chemical Changes
06 Physical and Chemical Changes
Every day you come across many changes in your surroundings. These changes may involve one or more substances. For example, yourmother may ask you to dissolve sugar in water to make a cold drink. Making a sugar solution is a change. Similarly, setting curd from milk is a change.Sometimes milk becomes sour. Souring of milk is a change. Stretched rubber band also represents a change.
- 07 Weather, Climate and Adaptations of Animals to Climate
07 Weather, Climate and Adaptations of Animals to Climate
Do you remember the things that you were asked to pack when you were heading for a hill station? When the sky is cloudy, your parents insist that you carry an umbrella. Have you heard elders in your family discuss the weather before planning a family function? You must have also heard the experts discussing the weather before the start of a game.Have you ever wondered why? The weather may have a profound effect on the game. It has a profound effect on our lives. Many of our daily activities are planned based on the weather predicted for that day. There are daily reports of the weather on the television and radio and in the newspapers. But do you know what this weather really is?
- 08 Winds, Storms and Cyclones
08 Winds, Storms and Cyclones
Orissa was hit by a cyclone with wind speed of 200 km/h on 18 October 1999. The cyclone smashed 45,000 houses making 7,00,000 people homeless. On 29 October the same year, a second cyclone with wind speed of 260 km/h hit Orissa again. It was accompanied by water waves about 9 m high. Thousands of people lost their lives. Property worth crores of rupees was destroyed. The cyclone affected agriculture, transport,communication, and electricity supply.
- 09 Soil
Soil is one of the most important natural resources. It supports the growth of plants by holding the roots firmly and supplying water and nutrients. It is the home for many organisms. Soil is essential for agriculture. Agriculture provides food, clothing and shelter for all. Soil is thus an inseparable part of our life. The earthy fragrance of soil after the first rain is always refreshing.
- 10 Respiration in Organisms
10 Respiration in Organisms
One day Boojho was eagerly waiting to meet his grandparents who were coming to the town after a year. He was in a real hurry as he wanted to receive them at the bus-stop. He ran fast and reached the bus-stop in a few minutes. He was breathing rapidly. His grandmother asked him why he was breathing so fast. Boojhotold her that he came running all the way.But the question got stuck in his mind.He wondered why running makes a person breathe faster. The answer to Boojhoís question lies in understanding why we breathe. Breathing is a part of respiration. Let us learn about respiration.
- 11 Transportation in Animals and Plants
11 Transportation in Animals and Plants
You have learnt earlier that all organisms need food, water and oxygen for survival. They need to transport all these to various parts of their body. Further, animals need to transport wastes to parts from where they can be removed. Have you wondered how all this is achieved? Look at Fig. 11.1. Do you see the heart and the blood vessels? They function to transport substances and together form the circulatory system. In this chapter you shall learn about transport of substances in plants and animals.
- 12 Reproduction in Plants
12 Reproduction in Plants
To produce its kind is a characteristic of all living organisms. You have already learnt this in Class VI. The production of new individuals from their parents is known as reproduction. But, how do plants reproduce? There are different modes of reproduction in plants which we shall learn in this chapter.
- 13 Motion and Time
13 Motion and Time
In Class VI, you learnt about different types of motions. You learnt that a motion could be along a straight line,it could be circular or periodic. Can you recall these three types of motions?
- 14 Electric Current and its Effects
14 Electric Current and its Effects
You might have tried the game ‘How steady is your hand?’ suggested in Chapter 12 of Class VI. If not, you may try it out now. Paheli and Boojho had also set up the game by connecting an electric circuit as suggested in Class VI. They had lots of fun trying it out with their families and friends. They enjoyed it so much that they decided to suggest it to a cousin of theirs who stayed in a different town. So, Paheli made a neat drawing showing how the various electric components were to be connected.
- 15 Light
You might have seen a beam of sunlight when it enters a room through a narrow opening or a hole. You may have also seen beams of light from the headlamps of scooters, cars and engines of trains [Fig. 15.1 (a)]. Similarly, a beam of light can be seen from a torch. Some of you may have seen a beam of searchlight from a light house or from an airport tower.
- 16 Water: A Precious Resource
16 Water: A Precious Resource
“Jal Hai, To Kal Hai”
“If you have water, you can think of the future”
- 17 Forests: Our Lifeline
17 Forests: Our Lifeline
- 18 Wastewater Story
18 Wastewater Story
WATER, OUR LIFELINE
Clean water is a basic need of human
being. Let us make a mindmap of the
many uses of clean water.