Sasmita madam
Fundamental Unit of Life Page No. 51 Q1. Who discovered cells and how? Ans: The cell was first discovered by Robert Hooke in 1665. He examined thin slices of cork under a self-made microscope and saw a multitude of tiny hollow spaces that he remarked looked like the walled compartments of a honeycomb. He termed these spaces as ‘cell’ meaning ‘small room’ in Latin. Microscope and Cork cells Q2. Why is the cell called the structural and functional unit of life? Ans: All living organisms are made up of cells. This shows that the cell is the structural unit of life. Each living cell can perform certain basic functions that are characteristic of all living forms. Example: (i) Phagocytic cells eat or kill unwanted or foreign particles inside the body (e.g., WBCs). (ii) Some cells secrete enzymes and hormones, e.g., pancreatic cells, small intestinal cells, and liver cells. Page No. 53 Q1. How do substances like CO₂ and water move in and out of the cell? Discuss. Ans: CO₂ mo...