NCERT Solutions Curiosity Chapter 2 In-text Questions — What Are the Levels of Organisation in the Body of a Living Organism?
Book page 14 Updated on2026-09-05
Q1.
But how do these cells help in performing various functions in the body? Let us find out.
Answer
Cells of one kind group together, and the group does a job that no single cell could do alone. The digestive system, which you studied in Grade 7, shows this clearly.
The food pipe contains a group of muscle cells. These cells contract and relax in a wave-like manner, pushing the food down to the stomach. The wave is possible only because the cells are thin, flexible and spindle-shaped, and because they act one after another rather than all at once.
The stomach wall also has muscle cells; these churn the food.
Other cells in the inner lining of the stomach produce digestive juices and acid that help break down the food.
None of these cells digests food by itself. Digestion is possible because all of them work together.
The levels of organisation (Fig. 2.7), with the digestive system as the example.
The idea behind it: a group of similar cells forms a tissue; different tissues are organised into an organ; several organs working together make an organ system; and all the organ systems together make the complete organism. The cell is the basic unit of life, just as a brick is the basic unit of a wall — but a single brick is not a wall, and a single cell is not a stomach.