| Classwise Additional Science Questions with Solutions (Class 6th to 10th) | ||||||||||||||
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| Classwise Additional Science Questions with Solutions (Class 11th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
| Classwise Additional Science NCERT Questions with Solutions (Class 12th) | ||||||||||||||
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Class 7th Science Additional Questions
1. Nutrition In Plants
This chapter explores how plants obtain nutrients for their survival. It focuses on **autotrophic nutrition**, where green plants produce their own food through **photosynthesis** using sunlight, water, carbon dioxide ($\textsf{CO}_2$), and minerals. The process, vital for all life as it provides food and oxygen, is explained. **Heterotrophic nutrition** in plants, such as parasitic plants (e.g., Cuscuta) obtaining food from hosts, saprophytic plants (e.g., fungi, though sometimes classified separately) absorbing nutrients from dead matter, and insectivorous plants (e.g., Pitcher plant) trapping insects for nutrients, is also discussed, highlighting the diverse nutritional strategies in the plant kingdom.
2. Nutrition In Animals
This chapter explains how animals obtain and process food, as they are **heterotrophs**, depending on plants or other animals for sustenance. It describes the different steps involved in animal nutrition: **ingestion** (taking in food), **digestion** (breaking down complex food into simpler substances), **absorption** (uptake of digested food), **assimilation** (utilisation of absorbed food), and **egestion** (removal of undigested waste). The structure and function of the **human digestive system** are explained in detail. The process of digestion in other animals like grass-eating animals (ruminants) and Amoeba is also discussed, showcasing varied feeding mechanisms.
3. Fibre To Fabric
Building upon knowledge of fibres, this chapter delves specifically into obtaining **animal fibres**, particularly **wool** and **silk**. It describes how wool is obtained from the fleece of animals like sheep, goat, and yak through processes like shearing, scouring, sorting, and spinning to make woollen yarn and fabric. The life cycle of the **silk moth** and the process of obtaining silk fibre from cocoons through **sericulture** are explained. This chapter highlights the techniques used to convert these natural animal products into valuable textiles used for clothing and other purposes.
4. Heat
This chapter introduces the concepts of **heat** and **temperature**. Heat is defined as a form of energy transferred due to temperature difference, always flowing from hotter to colder objects. Temperature is a measure of the degree of hotness or coldness. Different scales for measuring temperature (Celsius, Fahrenheit) and the use of **thermometers** (clinical and laboratory) are discussed. The three primary modes of **heat transfer** – **conduction** (through solids by particle vibration), **convection** (through fluids by bulk movement), and **radiation** (via electromagnetic waves, even through vacuum) – are explained with everyday examples like cooking and feeling warmth from a fire.
5. Acids, Bases And Salts
This chapter explores the properties of three important classes of chemical substances: **acids**, **bases**, and **salts**. Acids are typically sour (e.g., vinegar), while bases are bitter and feel soapy (e.g., soap solution). **Indicators**, such as litmus paper, turmeric, and china rose extract, are used to test if a substance is acidic or basic. The reaction between an acid and a base, resulting in the formation of a salt and water, is called **neutralisation**. Examples of acids, bases, and salts found in nature, laboratories, and daily life are discussed.
6. Physical And Chemical Changes
This chapter helps distinguish between two fundamental types of changes observed in matter. A **physical change** alters the form or appearance of a substance but not its chemical composition; these changes are often reversible (e.g., melting ice, dissolving sugar in water, tearing paper). A **chemical change** results in the formation of new substances with different properties; these changes are usually irreversible and may involve heat, light, gas evolution, or precipitate formation (e.g., burning wood, rusting of iron, cooking food). Recognizing these differences is key to understanding transformations around us.
7. Weather, Climate And Adaptations Of Animals To Climate
This chapter differentiates between **weather** (short-term atmospheric conditions of a place) and **climate** (long-term average weather pattern of a region). Factors influencing weather and climate are discussed. A key focus is on how animals exhibit special features or behaviors called **adaptations** that help them survive and thrive in specific climatic conditions. Examples of adaptations in animals living in extremely cold regions (e.g., polar bears, penguins) and tropical rainforests (e.g., monkeys, elephants) are presented, illustrating the remarkable ways life forms are suited to their environment.
8. Winds, Storms And Cyclones
This chapter explores the dynamics of air movement and associated weather phenomena. It explains that **wind** is caused by the movement of air from regions of high pressure to low pressure, often created by uneven heating of the Earth's surface. The chapter discusses how increasing wind speed and pressure differences can lead to **storms** and powerful weather systems like **cyclones**. The destructive nature of cyclones, particularly for coastal regions, is highlighted. Safety measures and preparedness during storms and cyclones are also discussed, emphasizing the importance of understanding and responding to these natural events.
9. Soil
**Soil** is a vital natural resource supporting plant life and is formed through the weathering of rocks. This chapter discusses the composition of soil, including mineral particles, humus (organic matter), water, air, and living organisms. Different types of soil (**sandy, clayey, loamy**) are described based on particle size and properties like water holding capacity and percolation rate. The chapter addresses the issue of **soil erosion** (removal of the fertile top layer) and methods for **soil conservation**, emphasizing the importance of protecting this precious, slow-forming resource for agriculture and maintaining ecosystems.
10. Respiration In Organisms
This chapter explains **respiration**, the essential life process by which living organisms obtain energy from food. It discusses **aerobic respiration** (requiring oxygen) and **anaerobic respiration** (without oxygen). Respiration in various organisms is covered: breathing (external respiration) and cellular respiration in humans, respiration through skin in earthworms, through tracheae in insects, and through gills in fish. Respiration in plants, involving gas exchange through stomata (leaves) and lenticels (stems), is also detailed, highlighting the mechanisms organisms use to release energy for their metabolic activities.
11. Transportation In Animals And Plants
This chapter explores how essential substances like nutrients, water, gases, and waste products are transported within living organisms. In **animals**, the **circulatory system** (blood, blood vessels, heart) is the primary transport system. The structure and function of the human circulatory system and heart are explained. In **plants**, **xylem** tissues transport water and minerals from roots to leaves, while **phloem** tissues transport food (sugars) synthesized during photosynthesis from leaves to other parts. The process of **transpiration** also plays a role in water movement, showcasing the sophisticated transport networks in living beings.
12. Reproduction In Plants
This chapter explains how plants produce new individuals, ensuring the continuation of plant species. It discusses both **asexual reproduction**, which involves a single parent and methods like vegetative propagation (using plant parts like roots, stems, leaves), budding, fragmentation, and spore formation, and **sexual reproduction**, which typically involves two parents and the fusion of gametes, occurring in flowers. The processes of **pollination** (transfer of pollen) and **fertilisation** (fusion of male and female gametes) leading to the formation of seeds and fruits are explained, highlighting the diversity of reproductive strategies in the plant kingdom.
13. Motion And Time
This chapter introduces the concepts of **motion** and its measurement using time. It defines motion and discusses different types of motion, including uniform motion (constant speed) and non-uniform motion (changing speed). The necessity of measuring time accurately using various devices is discussed. The concept of **speed** ($\textsf{Speed} = \frac{\textsf{Distance}}{\textsf{Time}}$) is introduced as the rate of change of position. Methods for measuring speed and representing motion using **distance-time graphs** are explained, providing quantitative tools for analyzing the movement of objects.
14. Electric Current And Its Effects
This chapter explores the effects produced by the flow of **electric current**. It revisits the components of a simple electric circuit and how they are represented using standard symbols. The chapter focuses on the **heating effect of electric current**, where electrical energy is converted into heat (e.g., in electric heaters, bulbs). It also discusses the **magnetic effect of electric current**, where a current-carrying wire produces a magnetic field around it, explaining the working principle of an electromagnet. The chapter emphasizes 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 phenomenon of **reflection**, the bouncing of light off surfaces like mirrors. The laws of reflection and image formation by **plane mirrors** are discussed. Image formation by **spherical mirrors** (concave and convex) is also introduced. The chapter briefly covers the concept of **refraction** (bending of light) and how light enables us to see the world, highlighting the fundamental principles of optics.
16. Water: A Precious Resource
This chapter highlights the vital importance of **water** and the increasing concerns about its availability. It discusses various sources of fresh water and the different forms water takes. The continuous circulation of water on, above, and below the Earth's surface through the **water cycle** is explained. The chapter emphasizes that usable water is a **precious resource** and discusses the causes of water scarcity. Methods for **water conservation**, such as rainwater harvesting, drip irrigation, and reducing wastage, are highlighted, stressing the urgent need for responsible water management for sustainable living, especially relevant in water-stressed regions of India.
17. Forests: Our Lifeline
Forests are vital ecosystems that provide numerous benefits to humans and the environment. This chapter explores forests as complex living systems, highlighting their role in maintaining ecological balance, preventing soil erosion, influencing the water cycle, and purifying air. It discusses the diversity of organisms found in forests and the concept of **food chains** and **food webs**, illustrating the interdependence among living beings. The chapter emphasizes the importance of **forest conservation** for timber, medicines, livelihoods, and protecting biodiversity, showcasing forests as essential for life and sustainable development, a valuable natural heritage in India.
18. Wastewater Story
This chapter addresses the issue of **wastewater** generated from various sources like homes, industries, and hospitals. It explains what wastewater is and the impurities it contains. The process of **wastewater treatment** in a **sewage treatment plant (STP)** is described, involving multiple stages like physical, chemical, and biological processes to remove pollutants before releasing the treated water back into water bodies. The chapter emphasizes the importance of proper sanitation and wastewater management to prevent pollution and protect public health and the environment, highlighting the need for effective infrastructure, especially in urban areas in India.