| Non-Rationalised Science NCERT Notes and Solutions (Class 6th to 10th) | ||||||||||||||
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| Non-Rationalised Science NCERT Notes and Solutions (Class 11th) | ||||||||||||||
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| Non-Rationalised Science NCERT Notes and Solutions (Class 12th) | ||||||||||||||
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Class 7th Science NCERT Notes and Solutions (Non-Rationalised)
1. Nutrition In Plants
This chapter explains how plants obtain nutrients. Plants are autotrophs, meaning they produce their own food through **photosynthesis**. The process involves using sunlight, water, carbon dioxide ($\textsf{CO}_2$), and minerals to synthesize carbohydrates. Heterotrophic nutrition in plants, such as parasitic plants (like Cuscuta) and insectivorous plants (like Pitcher plant), is also discussed. The chapter highlights the vital role of photosynthesis for all life on Earth.
2. Nutrition In Animals
This chapter explores how animals obtain and process food, as they are heterotrophs. It describes the different modes of nutrition, including ingestion, digestion, absorption, assimilation, and egestion. The digestive system in humans is explained in detail, covering the mouth, oesophagus, stomach, small intestine, large intestine, and associated glands. Digestion in other animals like grass-eating animals (ruminants) and amoeba is also briefly discussed, highlighting adaptations for obtaining nutrients.
3. Fibre To Fabric
Building upon Class 6 concepts, this chapter focuses on animal fibres, particularly wool and silk. It describes how wool is obtained from sheep and other animals through processes like shearing, scouring, sorting, and spinning. The life cycle of the silk moth and the process of obtaining silk from cocoons through sericulture are explained. Understanding these processes reveals how these valuable natural fibres are produced and processed into fabric.
4. Heat
This chapter delves into the concept of heat and temperature. It explains that heat is a form of energy that flows from a hotter object to a colder one. Different scales for measuring temperature, such as Celsius and Fahrenheit, and the use of thermometers (clinical and laboratory) are discussed. The three modes of heat transfer – **conduction** (in solids), **convection** (in fluids), and **radiation** (through empty space) – are explained with daily life examples.
5. Acids, Bases And Salts
This chapter introduces the properties of acids, bases, and salts. Acids are typically sour, while bases are bitter and soapy. Indicators like litmus paper, turmeric, and china rose are used to distinguish between acidic and basic substances. The process of **neutralisation**, where an acid reacts with a base to form salt and water, is explained. Examples of acids, bases, and salts found in nature and daily life are provided.
6. Physical And Chemical Changes
This chapter helps distinguish between **physical changes**, which alter the appearance or state of a substance but not its chemical composition (like melting wax or tearing paper), and **chemical changes**, which result in the formation of new substances with different properties (like burning magnesium or rusting iron). The chapter uses various examples and activities to illustrate these concepts and the irreversibility often associated with chemical changes.
7. Weather, Climate And Adaptations Of Animals To Climate
This chapter differentiates between weather (short-term atmospheric conditions) and climate (long-term average weather pattern). It discusses factors influencing weather and climate. A key focus is on how animals are **adapted** to survive in specific climates, such as polar regions (e.g., polar bears, penguins) and tropical rainforests (e.g., monkeys, elephants). Understanding adaptations reveals the remarkable ways life forms cope with their environmental challenges.
8. Winds, Storms And Cyclones
This chapter explores the power of moving air. It explains that wind is caused by differences in air pressure and that air expands on heating. The formation of winds, thunderstorms, and dangerous phenomena like **cyclones** is discussed. Safety measures to be taken during storms and cyclones are highlighted, particularly relevant in coastal areas of India. Understanding these natural events helps in preparedness and minimizing damage.
9. Soil
Soil is a vital natural resource supporting plant growth. This chapter discusses the formation of soil through weathering and its composition (minerals, organic matter, water, air, living organisms). Different types of soil (sandy, clayey, loamy) are described based on particle size and properties like water percolation rate. Soil erosion, its causes, and methods for soil conservation are also covered, emphasizing the importance of healthy soil for agriculture and the environment.
10. Respiration In Organisms
Respiration is the process by which organisms obtain energy from food. This chapter explains aerobic respiration (requiring oxygen) and anaerobic respiration (without oxygen). Respiration in humans is detailed, including breathing and cellular respiration. Respiration in other organisms like earthworms (through skin), insects (tracheae), fish (gills), and plants (through stomata and lenticels) is also discussed. Understanding respiration reveals how living beings release energy for their activities.
11. Transportation In Animals And Plants
This chapter explores how essential substances are transported within living organisms. In animals, the circulatory system (blood, blood vessels, heart) transports nutrients, oxygen, and waste products. The human circulatory system is explained, along with the lymphatic system. In plants, **xylem** transports water and minerals from roots to leaves, while **phloem** transports food (sugars) from leaves to other parts. Transpiration, the loss of water vapor from leaves, is also discussed.
12. Reproduction In Plants
This chapter explains how plants produce new individuals. It covers **asexual reproduction** methods like vegetative propagation (through stems, roots, leaves), budding, fragmentation, and spore formation. **Sexual reproduction** in plants, involving flowers, is also introduced, detailing pollination (transfer of pollen) and fertilisation (fusion of male and female gametes) leading to seed and fruit formation. Understanding plant reproduction is vital for agriculture and maintaining plant populations.
13. Motion And Time
This chapter builds upon the concept of motion by introducing the measurement of time and speed. Different types of motion (uniform and non-uniform) are discussed. Various devices used to measure time historically and currently are mentioned. The concept of **speed** ($\textsf{Speed} = \frac{\textsf{Distance}}{\textsf{Time}}$) is introduced as the rate of change of position, and how to measure and represent it using graphs is explained, forming a basis for further physics studies.
14. Electric Current And Its Effects
This chapter explores the effects produced by electric current. It revisits electric circuits and components. The **heating effect of electric current** (e.g., in electric heaters, bulbs) and the **magnetic effect of electric current** (producing a magnetic field around a wire, used in electromagnets) are explained. Simple circuit diagrams are used to represent connections. The chapter also introduces safety precautions when dealing with electricity.
15. Light
This chapter delves deeper into the properties of light. It confirms that light travels in straight lines and explains the formation of images by plane mirrors. Reflection of light from different surfaces and the laws of reflection are discussed. Image formation by spherical mirrors (concave and convex) is briefly introduced. The chapter also explores the scattering of light, explaining phenomena like why the sky appears blue.
16. Water: A Precious Resource
This chapter emphasises the importance and scarcity of water. It discusses different forms of water and sources of fresh water. The uneven distribution of water resources and the reasons for water scarcity are explained. Methods of water conservation, rainwater harvesting, and efficient water management practices are highlighted. The chapter stresses the need for responsible usage and conservation of this precious resource, particularly relevant in regions facing water stress in India.
17. Forests: Our Lifeline
Forests are vital ecosystems providing numerous benefits. This chapter explores forests as dynamic living entities, discussing their role in the water cycle, preventing soil erosion, purifying air, and providing timber, medicines, and other products. It explains the concept of a food chain and food web within a forest ecosystem and highlights the interdependence of various organisms. The chapter stresses the importance of forest conservation for ecological balance and human well-being.
18. Wastewater Story
This chapter addresses the issue of wastewater and its management. It explains what wastewater is and where it comes from. The process of wastewater treatment in a sewage treatment plant (STP) is described, including physical, chemical, and biological processes to remove pollutants before releasing treated water. Proper sanitation practices and alternatives like composting toilets are discussed, emphasizing the importance of managing wastewater to prevent pollution and protect public health.