Title CBSE Class 10 Science Question Paper 2024.pdf ✅

3 www.bankofbiology.com (c) Tiger, grass, snake, frog (d) Grasshopper, grass, snake, frog, eagle Answer: (c) Tiger, grass, snake, frog 16. In which of the following organisms, multiple fission is a means of asexual reproduction? 1 (a) Yeast (b) Leishmania (c) Paramecium (d) Plasmodium Answer: (d) Plasmodium For Q. Nos. 17 to 20, two statements are given – One labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below: (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A). (c) Assertion (A) is true, but Reason (R) is false. (d) Assertion (A) is false, but Reason (R) is true. 17. Assertion (A): Hydrogen gas is not evolved when zinc reacts with nitric acid. Reason (R): Nitric acid oxidises the hydrogen gas produced to water and itself gets reduced. 1 Answer: (a) Both Assertion (A) and Reason (R) are true and Reason (R) is (A the correct explanation of the Assertion). 18. Assertion (A): Accumulation of harmful chemicals is maximum in the organisms at the highest trophic level of a food chain. Reason (R): Harmful chemicals are sprayed on the crops to protect them from diseases and pests. 1 Answer: (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A). 19. Assertion (A): The rate of breathing in aquatic organisms is much faster than in terrestrial organisms. Reason (R): The amount of oxygen dissolved in water is very high as compared to the amount of oxygen in air. 1 Answer: (c) Assertion (A) is true, but Reason (R) is false. 20. Assertion (A): The rainbow is a natural spectrum of sunlight in the sky. 1 Reason (R): The rainbow is formed in the sky when the sun is overhead and water droplets are also present in the air. Answer: (d) Assertion (A) is false, but Reason (R) is true. SECTION – B 21. Name the type of chemical reaction in which calcium oxide reacts with water. Justify your answer by giving balanced chemical equation for the chemical reaction. 2 Answer: The reaction between calcium oxide and water is an example of a combination reaction. CaO + H2O → Ca(OH)2 22. State one role of each of the following in the human digestive system: 2 (i) Hydrochloric acid (ii) Villi (iii) Anal Sphincter (iv) Lipase Answer: (i) Hydrochloric acid (HCl) creates an acidic environment in the stomach, which helps in the digestion of proteins and activates pepsinogen into pepsin. (ii) Villi increase the surface area of the small intestine for the absorption of nutrients. (iii) The anal sphincter controls the release of faeces from the rectum through the anus. (iv) Lipase is an enzyme that breaks down fats into fatty acids and glycerol in the small intestine. 23. (A) How is the movement of leaves of a sensitive plant different from the downward movement of the roots? 2 OR (B) There is a hormone which regulates carbohydrate, protein, and fat metabolism in our body. Name the hormone and the gland which secretes it. Why is it important for us to have iodised salt in our diet? 2 Answer: