Science · World of living · chapter 5 of 13

Class 10 Science Chapter 5: Life Processes Assertion-reason questions with answers

2 assertion-reason questions on Life Processes, each with its answer and the reason, written from the NCERT chapter. Open a question's solution to check your working; then take the free test to find your next chapter. Each question gives an Assertion (A) and a Reason (R); choose how they stand to each other.

Question 1
Assertion (A): The gastric glands release mucus along with hydrochloric acid. Reason (R): Mucus protects the inner lining of the stomach from the action of the acid.
Show answer

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Both are true. Mucus is released with the acid precisely to protect the stomach lining from that acid, so R explains A.

Question 2
Assertion (A): The ventricles of the human heart have thicker muscular walls than the atria. Reason (R): Valves in the heart prevent blood from flowing backwards when the atria or ventricles contract.
Show answer

Answer: (b) Both A and R are true, but R is not the correct explanation of A.

Both are true, but the ventricle walls are thick because the ventricles pump blood into the various organs; the valves do not explain the thickness.

Take the free Class 10 Science testSee the Class 10 flashcards

← Chapter 4: Carbon and its CompoundsChapter 6: Control and Coordination →