Science(7th cbse) 1 Nutrition in Plants. 2 Nutrition in Animals. 3 Fibre to Fabric. 4 Heat. 5 Acids, Bases and Salts. 6 Physical and Chemical Changes

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1 Science(7th cbse) Chapter Number Chapter Name 1 Nutrition in Plants 2 Nutrition in Animals 3 Fibre to Fabric 4 Heat 5 Acids, Bases and Salts 6 Physical and Chemical Changes 7 Weather, Climate and Adaptations of Animals to Climate 8 Winds, Storms and Cyclones 9 Soil 10 Respiration in Organisms 11 Transportation in Animals and Plants 12 Reproduction in Plants 13 Motion and Time 14 Electric Current and its Effects 15 Light 16 Water: A Precious Resource 17 Forests: Our Lifeline 18 Wastewater Story

2 1 Nutrition in Plants Plants make their own food using sunlight, water, carbon dioxide, and other minerals present in their environment. Most of the plants use photosynthesis process to make their food using a green pigment in their leaves called Chlorophyll. Some plants that do not have chlorophyll use different methods to make their food. They take food from other plants or even eat insects. 2 Nutrition in Animals Animal nutrition covers nutrient requirements, how the food is consumed, and how the body utilizes the food. Digestion is process that converts complex food substances to simpler ones. Nutrition involves the following: 1. Ingestion, 2. Digestion, 3. Absorption, 4. Assimilation, and 5. Egestion Ruminants are grazing animals like cows and deers. They quickly ingest the food and store it in rumen and later brings the food back to mouth for chewing it well. Amoeba ingests the food using its feet. 3 Fibre to Fabric Silk comes from silkworms and wool comes from sheep, goat and yak. Sheep hair is sheared off from the its body, scoured, sorted, dried, dyed, spun and woven to yield wool. Silkworms are caterpillars of silk moth, during their life cycle, the worms spin cocoons of silk fibres. Silk fibres are separated out from the cocoon and reeled into silk threads. The silk threads can be weaved into silk cloth. 4 Heat Thermometer is a device that measures the temperature of an object in a reliable manner. We can use a clinical thermometer to measure ourbody temperature. Heat is transferred from a body at a higher temperature to a body at lower temperature. Conduction, Convection, and Radiation are the different methods of heat transfer. Heat passes easily through heat conductors. Heat does not pass easily through insulators. Dark colored objects absorb heat more easily through radiation. 5 Acids, Bases and Salts Do you know what makes lemon and vinegar sour in taste? It is Acids. Acids taste sour while Bases taste bitter and feel soapy to touch. Litmus is an indicator as it can be used to test whether a substance is acidic or basic.

3 Acid turns blue litmus red and Bases turn red litmus blue. Substances are called neutral when they are neither acidic nor basic. When you combine an acid and a base, they neutralise each other to form salt. The resulting salt could be acidic, basic, or neutral. 6 Physical and Chemical Changes Have you noticed, changes happen everywhere and at all times? All changes can be divided into two categories - Physical and Chemical. Physical changes are the changes in physical properties that does not produce any new substances. These changes can be reversed like - melting of ice. Chemical changes are permanent and the original substances loses its composition and properties. These changes cannot be reversed like - rusting of iron. 7 Weather, Climate and Adaptations of Animals to Climate Weather is the daily atmospheric condition of a place. It is determined by the temperature, humidity, rainfall, wind speed etc. Sun drives the changes in the weather. Climate is the average weather pattern of a place taken over a period of 25 years. Animals adapt themselves to the climatic conditions of a place. Animals may migrate to different places to escape from cold and harsh conditions like the polar region. Many animals and plants are found in the tropical region due to the hospitable climate. 8 Winds, Storms and Cyclones Air exerts pressure on its surroundings. Air expands when heated and contracts when cooled. When the air is heated it becomes lighter and it rises. This causes the air pressure to reduce. The cooler air in the surrounding areas moves in to balance the pressure. This movement of air is called the wind. Wind movements are caused by uneven heating of earth. The water vapor in the air causes the rain. High speed winds with severe rain are calledcyclones. 9 Soil Apart from water, air and sunshine; all living beings need SOIL for existence. A section through different layers of the soil is called the soil profile. Soil has various layers called horizons. Sandy, loamy, and clayey are the different types of soils. Water percolates at different rates through different types of soil. The water held in the soil is called the soil moisture. Different types of crops are grown in different types of soils. 10 Respiration in Organisms Respiration releases energy from food. The oxygen that we inhale breaks down glucose into carbon dioxide and water. This releases the energy.

4 Aerobic respiration uses oxygen to breakdown the food. Anaerobic respiration does not use oxygen. For example, when we exercise, our muscles do not have enough oxygen. Therefore, the muscles breakdown food without the oxygen. Breathing is a process of respiration during which oxygen is inhaled and carbon-dioxide is exhaled. Humans and animals use lung as the respiratory organ. Earthworm breathes through its skin and fish uses its gills. Plants use their leaves and roots to take in air. 11 Transportation in Animals and Plants Living organisms need a transport system to transport food, gases, mineral salts, hormones which is required for normal functioning. Transportation of substances is done by the Circulatory System comprising of blood, blood vessels (arteries, veins and capillaries) and heart. The movement of the blood from the heart to all parts of the body and back to the heart is calledcirculation of Blood. During, this blood flows to arteries with pressure called blood pressure. It is measured with an instrument called Sphygmomanometer. Transportation of water and food take place by Xylem (water) and Phloem (food) through diffusion and osmosis. Diffusion - movement of gas or liquid from higher concentration region to lower concentration region Osmosis - movement of water molecules from a weaker solution to a stronger solution through a semipermeable membrane. 12 Reproduction in Plants Living things give birth to young ones by the process called Reproduction. Plants reproduce asexually by - Budding, Spore formation, Fragmentation. Vegetative reproduction (vegetative part give rise to new ones) through Leaf or Stem or Root Artificial vegetative propagation - growing plants using artificial methods such as cutting, layering and grafting. Tissue culture is a modern method of vegetative reproduction. Sexual reproduction - Flower is the reproductive part of a plant. Male part of flower is Stamen - filament, anther. Anthers have pollen grains, which are the male sex cells. Female part of a flower is Pistil. It has Ovary, Ovules, Style, Stigma. Ovules contain egg cell. The transfer of pollen grains called Pollination will take place either by self pollination or cross pollination. The fusion of male gamete and female gamete called Fertilisation. Fertilisation results into the formation of zygote. Ovary grows into the fruit, ovules develop into seeds, Seeds contain baby plant called an embryo and reserve food in fleshy cotyledons. Dispersal of seeds take place. Seed germinates under favourable conditions

5 13 Motion and Time Motion makes the world go 'round'. When we think of motion we often think of cars, bicycles, kids running, basketballs bouncing and airplanes flying. But motion is so much more. A body is said to be in motion if it changes its position with respect to fixed point or objects around it. Explore the different types of motions in your daily life: Oscillatory motion - motion of swing Rectilinear motion - motion of car on straight road Rotational motion - motion of merry-go-round Calculate the speed of an object by finding out the distance covered by the object in unit time. Also compare which object is moving faster. Learn about simple pendulum and methods to find its time period. Motion of objects can be presented in pictorial form by their distance-time graphs. Learn to draw different distance-time graphs for uniform motion and non-uniform motion 14 Electric Current and its Effects Do you know what is common between an electric eel, a bolt of lightning, and a glowing bulb? It is electricity! An electric eel is a fish that makes its own electricity, Lightning is spark of electricity in the air and bulb uses electricity to glow. Electricity is a form of energy produced by charges. It is difficult to imagine our life without electricity. An electric circuit is closed path in which current flows. It comprises of electric components (cell or battery, bulb, switch ). Learn to make different electrical circuits and distinguish between open and closed circuit. Explore and understands the different effects of electricity in your daily life. Heating effect - Heating of Electric iron Mechanical effect - Working of Vacuum cleaner Magnetic effect - Working of electric bell Chemical effect - Polishing of artificial jewellery Learn to save electrical appliances from excessive current by using electric fuse. Current can rise due to following reasons : Overloading ( too many higher power appliances turned on ) Short circuiting ( live wire and neutral wire joined together ) Fluctuation in voltage

6 15 Light The branch of physics dealing with the properties and behaviour of light is called optics. Light is a form of energy which helps us to see the objects. Have you ever wondered why we are able to see the different objects around us, their images in a mirror or in a pond? This is simply due to reflection of light. It is the phenomenon of bouncing back of light after striking a smooth polished surface. Why is the word "ambulance" written backwards in ambulance car? This is due to lateral inversion -The phenomenon due to which the left side of an object appears to be right side of the object in its image in a reflecting medium (mirror ) and vice-versa is called lateral inversion. Enjoy interesting trivia related to spherical mirrors(concave and convex) and plane mirror, optics, sunlight. Understand the differences between mirrors and lenses. Learn about the formation of rainbow. Did you know that you can see a rainbow only when your back is towards the sun? 16 Water: A Precious Resource Water is one of the most precious resource on Earth and is necessary for all living beings. We use water for different purposes like drinking, cooking, bathing, washing and many more activities. Pure water is colorless, odorless and tasteless. 17 Forests: Our Lifeline We enjoy observing the beauty of nature but we never think about the living things that live on trees. Forest is an ecosystem with a community of trees, shrubs, herbs, microorganism and animals. Most life exists vertically in trees. This vertical part of forest is divided into overstorey, the canopy, understorey and the forest floor. Importance of forests - it provides food, shelter, oxygen, cools the atmosphere, recharges ground water. Useful products such as timber, oil, rubber etc. are obtained from forest Interdependence of plants and animals in forests: Food chain is a series of organisms in which each organism is eaten by the next member in the chain. Producers, consumers and decomposers are the members of food chain. A food web is a series of interconnected food chains representing the feeding relationships of the organisms 18 Wastewater Story self explanatory