CBSE Class 8 Science Important Questions

Below are 10 important questions from Class 8 Science chapters that are important for preparing well and understanding concepts easily.

1. What are the different methods of crop production?

Ans: Crop production involves several methods, including traditional farming, organic farming, and modern agricultural techniques. Traditional farming relies on manual labour and natural fertilisers, while organic farming uses no synthetic chemicals and focuses on sustainable practices. Modern agricultural techniques, such as precision farming and hydroponics, utilise technology and scientific methods to maximise yield and efficiency. Each method has its advantages and disadvantages, affecting the environment and food quality. Understanding these methods helps in choosing sustainable practices that ensure food security.

2. How do microorganisms benefit humans?

Ans: Microorganisms play a crucial role in various processes that benefit humans. They are essential in the production of antibiotics, which help fight infections. In agriculture, certain bacteria enhance soil fertility by fixing nitrogen, while fungi decompose organic matter, enriching the soil. Microorganisms are also vital in the food industry, used in the fermentation process to produce yoghurt, cheese, and other products. Moreover, they aid in waste management by breaking down organic waste. Understanding these benefits highlights the importance of microorganisms in our daily lives.

3. What is the process of fossil fuel formation?

Ans: Fossil fuels, such as coal and petroleum, are formed from the remains of ancient plants and animals that were buried under layers of sediment millions of years ago. Over time, heat and pressure transformed these organic materials into hydrocarbons. Coal is primarily formed from plant remains in swampy areas, while petroleum originates from marine organisms. The extraction and use of fossil fuels have significant impacts on energy production and the environment, making it crucial to understand their formation and implications.

4. What are the different types of combustion?

Ans: Combustion is the chemical process of burning, producing heat and light. There are three main types of combustion: complete, incomplete, and spontaneous. Complete combustion occurs when a fuel burns in sufficient oxygen, producing carbon dioxide and water. Incomplete combustion happens when there is a limited oxygen supply, resulting in carbon monoxide and soot. Spontaneous combustion occurs without an external ignition source, often due to high temperatures. Understanding these types is essential for safety and efficiency in various applications.

5. Why is conservation of biodiversity important?

Ans: Conserving biodiversity is vital for maintaining ecological balance and supporting life on Earth. Biodiversity contributes to ecosystem stability, resilience, and productivity. It provides essential services such as pollination, nutrient cycling, and climate regulation. Moreover, a diverse gene pool is crucial for food security and medicine development. Protecting habitats and species from extinction ensures the survival of ecosystems, which in turn supports human well-being. Awareness and action towards conservation are essential for a sustainable future.

6. How does reproduction occur in animals?

Ans: Reproduction in animals can be classified into two main types: sexual and asexual reproduction. Sexual reproduction involves the fusion of male and female gametes, resulting in offspring with genetic variation. This process includes courtship, mating, and fertilisation, leading to the development of embryos. In contrast, asexual reproduction occurs without the fusion of gametes, producing clones of the parent organism, as seen in certain species of starfish and bacteria. Understanding these reproductive methods is crucial for studying animal biology and conservation.

7. What are the changes that occur during adolescence?

Ans: Adolescence is a critical developmental stage marked by significant physical, emotional, and psychological changes. Physically, individuals experience growth spurts, changes in body composition, and the development of secondary sexual characteristics. Emotionally, adolescents may face mood swings, identity exploration, and increased independence. Psychologically, they begin to develop critical thinking and decision-making skills. Understanding these changes is essential for supporting adolescents during this transitional period, promoting healthy development and well-being.

8. How do force and pressure relate to each other?

Ans: Force and pressure are closely related concepts in physics. Force is defined as any push or pull acting on an object, while pressure is the force applied per unit area. When a force is exerted over a smaller area, the pressure increases. For example, a sharp knife can cut through materials easily because it exerts high pressure on a small surface area. Understanding this relationship is essential in various applications, from engineering to everyday situations, such as using a tire pump or medical equipment.

9. What are the effects of friction in our daily lives?

Ans: Friction is the resistance that occurs when two surfaces contact each other. It plays a vital role in our daily lives, enabling movement and preventing slipping. For example, friction allows us to walk without sliding and helps vehicles grip the road. However, friction can also cause wear and tear on surfaces, leading to energy loss in machines. Understanding the effects of friction helps in designing better tools and machines, improving safety, and increasing efficiency in various applications.

10. What causes sound and how does it travel?

Ans: Sound is produced by vibrating objects, which create pressure waves in the surrounding medium, typically air. These vibrations cause air molecules to compress and rarefy, forming sound waves that travel through the medium. Sound travels faster in solids and liquids than in gases due to the closer arrangement of particles. The pitch and volume of sound depend on the frequency and amplitude of the vibrations. Understanding how sound is generated and transmitted is essential for applications in communication, music, and technology.

Here are some key questions for Class 8 Science. For a clearer understanding of each chapter, refer to the Chapter-wise Important Questions table. This table will assist you in understanding the main concepts and preparing effectively for your exams.

How do Science Important Questions Class 8 Help You with Exams?

• Important questions help you focus on key concepts, which makes studying more effective and efficient. By knowing what to prioritise, you can ensure you understand the main ideas of each chapter.

• Practising these questions boosts your confidence and skills by allowing you to apply what you’ve learned. The more you practise, the more comfortable you’ll feel with the material.

• They can reveal topics you find challenging, giving you the opportunity to dedicate more time to those areas before the exam. This targeted approach helps you improve in specific subjects.

• Regularly revising important questions reinforces your memory, making it easier to recall information during the exam. Consistent practice helps solidify your understanding of the concepts.

• These questions prepare you for the exam format, allowing you to become familiar with the types of questions you might encounter. This also improves your time management skills during the test.

• Reviewing your answers helps you assess your progress and understand where you stand in your studies. It allows you to adjust your study methods based on what you find challenging or easy.

Vedantu's CBSE Class 8 Science important questions are a valuable resource for students preparing for exams. By focusing on key concepts and providing practice opportunities, these questions help students build confidence and improve their understanding of the subject. They also assist in identifying challenging areas, allowing for targeted study. Regular revision with these questions enhances problem-solving skills, making exam preparation more effective. Overall, using Vedantu's important questions can greatly support students in achieving success in their Class 8 Science exams.

Additional Study Materials for Class 8 Science