Science

Think It Over (Page 28) Q – How is the study of cells and tissues significant for understanding the life processes and human welfare? A – Studying cells and tissues helps scientists understand the natural biological processes that control how plants and animals grow, develop, and survive. By understanding these intricate processes, researchers can replicate … Read more

Think It Over Q – Why do suspended particles settle in muddy water over time but not in milk? A – In muddy water, the mud particles are quite large and heavy (it is a suspension). Gravity pulls these heavy particles down to the bottom over time. Milk, however, is a colloid. The fat and … Read more

Q: Where does a cell come from? A: A new cell comes from a pre-existing (already existing) cell through a process called cell division. When a living cell grows, it divides into new cells to help an organism grow and heal. Q: How have technological interventions facilitated the creation of new knowledge in understanding the … Read more

Question Set 1 (Page 3) 1. A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 10.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case? Answer: The work done … Read more

Page 2: Activity 3.1 What happens in the reaction flask? When the solutions X and Y are mixed, they react with each other. For example, if you mix copper sulphate (blue) and sodium carbonate, a chemical reaction happens and new substances are formed. Do you think that a chemical reaction has taken place? Yes, a … Read more

Activity 5.1 (Page 50)   Question: What do we observe as we look through the lens? Can we draw the structures that we are able to see through the microscope, on an observation sheet? Does it look like Fig. 5.2? Answer: When we look through the lens of the microscope, we see small structures that … Read more

Activity 11.1 Questions: “• Take a tuning fork and set it vibrating by striking its prong on a rubber pad. Bring it near your ear. • Do you hear any sound? • Touch one of the prongs of the vibrating tuning fork with your finger and share your experience with your friends. • Now, suspend … Read more

In-Text Questions and Answers What are canal rays? Answer: Canal rays are streams of positively charged particles discovered by E. Goldstein. They are also known as anode rays. These rays are produced in a gas discharge tube and move in a direction opposite to that of electrons. If an atom contains one electron and one … Read more

In-text Questions and Answers State the universal law of gravitation. Answer: The universal law of gravitation states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Write the formula to … Read more

In-Text Questions Answers 1. What is a tissue? A tissue is a group of similar cells that work together to perform a specific function in an organism. This organization allows the cells to be more efficient in carrying out tasks like movement, support, or transporting nutrients. 2. What is the utility of tissues in multi-cellular … Read more